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https://dev.mysql.com/doc/refman/8.4/en/data-dictionary-file-removal.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h2 class="title">
<a name="data-dictionary-file-removal">
</a>
16.2 Removal of File-based Metadata Storage
</h2>
</div>
</div>
</div>
<a class="indexterm" name="idm46045167771040">
</a>
<p>
In previous MySQL releases, dictionary data was partially stored
in metadata files. Issues with file-based metadata storage
included expensive file scans, susceptibility to file
system-related bugs, complex code for handling of replication and
crash recovery failure states, and a lack of extensibility that
made it difficult to add metadata for new features and relational
objects.
</p>
<p>
The metadata files listed below are removed from MySQL. Unless
otherwise noted, data previously stored in metadata files is now
stored in data dictionary tables.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="filename">
.frm
</code>
files: Table metadata files. With
the removal of
<code class="filename">
.frm
</code>
files:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
The 64KB table definition size limit imposed by the
<code class="filename">
.frm
</code>
file structure is removed.
</p>
</li>
<li class="listitem">
<p>
The Information Schema
<a class="link" href="information-schema-tables-table.html" title="28.3.38 The INFORMATION_SCHEMA TABLES Table">
<code class="literal">
TABLES
</code>
</a>
table's
<code class="literal">
VERSION
</code>
column reports a
hardcoded value of
<code class="literal">
10
</code>
, which is the
last
<code class="filename">
.frm
</code>
file version used in MySQL
5.7.
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
<code class="filename">
.par
</code>
files: Partition definition files.
<code class="literal">
InnoDB
</code>
stopped using partition definition
files in MySQL 5.7 with the introduction of native
partitioning support for
<code class="literal">
InnoDB
</code>
tables.
</p>
</li>
<li class="listitem">
<p>
<code class="filename">
.TRN
</code>
files: Trigger namespace files.
</p>
</li>
<li class="listitem">
<p>
<code class="filename">
.TRG
</code>
files: Trigger parameter files.
</p>
</li>
<li class="listitem">
<p>
<code class="filename">
.isl
</code>
files:
<code class="literal">
InnoDB
</code>
Symbolic Link files containing the location of
<a class="link" href="glossary.html#glos_file_per_table" title="file-per-table">
file-per-table
</a>
tablespace files created outside of the data directory.
</p>
</li>
<li class="listitem">
<p>
<code class="filename">
db.opt
</code>
files: Database configuration
files. These files, one per database directory, contained
database default character set attributes.
</p>
</li>
<li class="listitem">
<p>
<code class="filename">
ddl_log.log
</code>
file: The file contained
records of metadata operations generated by data definition
statements such as
<a class="link" href="drop-table.html" title="15.1.32 DROP TABLE Statement">
<code class="literal">
DROP TABLE
</code>
</a>
and
<a class="link" href="alter-table.html" title="15.1.9 ALTER TABLE Statement">
<code class="literal">
ALTER TABLE
</code>
</a>
.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/replication-gtids-failover.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="replication-gtids-failover">
</a>
19.1.3.5 Using GTIDs for Failover and Scaleout
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045145975472">
</a>
<a class="indexterm" name="idm46045145973984">
</a>
<p>
There are a number of techniques when using MySQL Replication with
Global Transaction Identifiers (GTIDs) for provisioning a new
replica which can then be used for scaleout, being promoted to
source as necessary for failover. This section describes the
following techniques:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="xref" href="replication-gtids-failover.html#replication-gtids-failover-replicate" title="Simple replication">
Simple replication
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="replication-gtids-failover.html#replication-gtids-failover-copy" title="Copying data and transactions to the replica">
Copying data and transactions to the replica
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="replication-gtids-failover.html#replication-gtids-failover-empty" title="Injecting empty transactions">
Injecting empty transactions
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="replication-gtids-failover.html#replication-gtids-failover-gtid-purged" title="Excluding transactions with gtid_purged">
Excluding transactions with gtid_purged
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="replication-gtids-failover.html#replication-gtids-restoring-mysqlbinlog" title="Restoring GTID mode replicas">
Restoring GTID mode replicas
</a>
</p>
</li>
</ul>
</div>
<p>
Global transaction identifiers were added to MySQL Replication for
the purpose of simplifying in general management of the
replication data flow and of failover activities in particular.
Each identifier uniquely identifies a set of binary log events
that together make up a transaction. GTIDs play a key role in
applying changes to the database: the server automatically skips
any transaction having an identifier which the server recognizes
as one that it has processed before. This behavior is critical for
automatic replication positioning and correct failover.
</p>
<p>
The mapping between identifiers and sets of events comprising a
given transaction is captured in the binary log. This poses some
challenges when provisioning a new server with data from another
existing server. To reproduce the identifier set on the new
server, it is necessary to copy the identifiers from the old
server to the new one, and to preserve the relationship between
the identifiers and the actual events. This is necessary for
restoring a replica that is immediately available as a candidate
to become a new source on failover or switchover.
</p>
<p>
<a name="replication-gtids-failover-replicate">
</a>
<b>
Simple replication.
</b>
The easiest way to reproduce all identifiers and transactions on
a new server is to make the new server into the replica of a
source that has the entire execution history, and enable global
transaction identifiers on both servers. See
<a class="xref" href="replication-gtids-howto.html" title="19.1.3.4 Setting Up Replication Using GTIDs">
Section 19.1.3.4, “Setting Up Replication Using GTIDs”
</a>
, for more information.
</p>
<p>
Once replication is started, the new server copies the entire
binary log from the source and thus obtains all information about
all GTIDs.
</p>
<p>
This method is simple and effective, but requires the replica to
read the binary log from the source; it can sometimes take a
comparatively long time for the new replica to catch up with the
source, so this method is not suitable for fast failover or
restoring from backup. This section explains how to avoid fetching
all of the execution history from the source by copying binary log
files to the new server.
</p>
<p>
<a name="replication-gtids-failover-copy">
</a>
<b>
Copying data and transactions to the replica.
</b>
Executing the entire transaction history can be time-consuming
when the source server has processed a large number of
transactions previously, and this can represent a major
bottleneck when setting up a new replica. To eliminate this
requirement, a snapshot of the data set, the binary logs and the
global transaction information the source server contains can be
imported to the new replica. The server where the snapshot is
taken can be either the source or one of its replicas, but you
must ensure that the server has processed all required
transactions before copying the data.
</p>
<p>
There are several variants of this method, the difference being in
the manner in which data dumps and transactions from binary logs
are transferred to the replica, as outlined here:
</p>
<div class="variablelist">
<dl class="variablelist">
<dt>
<span class="term">
Data Set
</span>
</dt>
<dd>
<div class="orderedlist">
<ol class="orderedlist" type="1">
<li class="listitem">
<p>
Create a dump file using
<a class="link" href="mysqldump.html" title="6.5.4 mysqldump — A Database Backup Program">
<span class="command">
<strong>
mysqldump
</strong>
</span>
</a>
on
the source server. Set the
<a class="link" href="mysqldump.html" title="6.5.4 mysqldump — A Database Backup Program">
<span class="command">
<strong>
mysqldump
</strong>
</span>
</a>
option
<a class="link" href="mysqldump.html#option_mysqldump_source-data">
<code class="option">
--source-data
</code>
</a>
to 1, to include a
<a class="link" href="change-replication-source-to.html" title="15.4.2.2 CHANGE REPLICATION SOURCE TO Statement">
<code class="literal">
CHANGE
REPLICATION SOURCE TO
</code>
</a>
statement with binary
logging information. Set the
<a class="link" href="mysqldump.html#option_mysqldump_set-gtid-purged">
<code class="option">
--set-gtid-purged
</code>
</a>
option to
<code class="literal">
AUTO
</code>
(the default) or
<code class="literal">
ON
</code>
, to include information about
executed transactions in the dump. Then use the
<a class="link" href="mysql.html" title="6.5.1 mysql — The MySQL Command-Line Client">
<span class="command">
<strong>
mysql
</strong>
</span>
</a>
client to import the dump file
on the target server.
</p>
</li>
<li class="listitem">
<p>
Alternatively, create a data snapshot of the source
server using raw data files, then copy these files to
the target server, following the instructions in
<a class="xref" href="replication-snapshot-method.html" title="19.1.2.5 Choosing a Method for Data Snapshots">
Section 19.1.2.5, “Choosing a Method for Data Snapshots”
</a>
. If you
use
<a class="link" href="innodb-storage-engine.html" title="Chapter 17 The InnoDB Storage Engine">
<code class="literal">
InnoDB
</code>
</a>
tables, you can
use the
<span class="command">
<strong>
mysqlbackup
</strong>
</span>
command from the
MySQL Enterprise Backup component to produce a consistent snapshot. This
command records the log name and offset corresponding to
the snapshot to be used on the replica. MySQL Enterprise Backup is a
commercial product that is included as part of a MySQL
Enterprise subscription. See
<a class="xref" href="mysql-enterprise-backup.html" title="32.1 MySQL Enterprise Backup Overview">
Section 32.1, “MySQL Enterprise Backup Overview”
</a>
for detailed
information.
</p>
</li>
<li class="listitem">
<p>
Alternatively, stop both the source and target servers,
copy the contents of the source's data directory to the
new replica's data directory, then restart the
replica. If you use this method, the replica must be
configured for GTID-based replication, in other words
with
<a class="link" href="replication-options-gtids.html#sysvar_gtid_mode">
<code class="literal">
gtid_mode=ON
</code>
</a>
. For
instructions and important information for this method,
see
<a class="xref" href="replication-howto-additionalslaves.html" title="19.1.2.8 Adding Replicas to a Replication Environment">
Section 19.1.2.8, “Adding Replicas to a Replication Environment”
</a>
.
</p>
</li>
</ol>
</div>
</dd>
<dt>
<span class="term">
Transaction History
</span>
</dt>
<dd>
<p>
If the source server has a complete transaction history in
its binary logs (that is, the GTID set
<code class="literal">
@@GLOBAL.gtid_purged
</code>
is empty), you can
use these methods.
</p>
<div class="orderedlist">
<ol class="orderedlist" type="1">
<li class="listitem">
<p>
Import the binary logs from the source server to the new
replica using
<a class="link" href="mysqlbinlog.html" title="6.6.9 mysqlbinlog — Utility for Processing Binary Log Files">
<span class="command">
<strong>
mysqlbinlog
</strong>
</span>
</a>
, with the
<a class="link" href="mysqlbinlog.html#option_mysqlbinlog_read-from-remote-server">
<code class="option">
--read-from-remote-server
</code>
</a>
and
<a class="link" href="mysqlbinlog.html#option_mysqlbinlog_read-from-remote-source">
<code class="option">
--read-from-remote-source
</code>
</a>
options.
</p>
</li>
<li class="listitem">
<p>
Alternatively, copy the source server's binary log files
to the replica. You can make copies from the replica
using
<a class="link" href="mysqlbinlog.html" title="6.6.9 mysqlbinlog — Utility for Processing Binary Log Files">
<span class="command">
<strong>
mysqlbinlog
</strong>
</span>
</a>
with the
<a class="link" href="mysqlbinlog.html#option_mysqlbinlog_read-from-remote-server">
<code class="option">
--read-from-remote-server
</code>
</a>
and
<a class="link" href="mysqlbinlog.html#option_mysqlbinlog_raw">
<code class="option">
--raw
</code>
</a>
options.
These can be read into the replica by using
<a class="link" href="mysqlbinlog.html" title="6.6.9 mysqlbinlog — Utility for Processing Binary Log Files">
<span class="command">
<strong>
mysqlbinlog
</strong>
</span>
</a>
<code class="literal">
>
</code>
<code class="filename">
<em class="replaceable">
<code>
file
</code>
</em>
</code>
(without the
<a class="link" href="mysqlbinlog.html#option_mysqlbinlog_raw">
<code class="option">
--raw
</code>
</a>
option) to export the binary log files to SQL files,
then passing these files to the
<a class="link" href="mysql.html" title="6.5.1 mysql — The MySQL Command-Line Client">
<span class="command">
<strong>
mysql
</strong>
</span>
</a>
client for processing. Ensure that all of the binary log
files are processed using a single
<a class="link" href="mysql.html" title="6.5.1 mysql — The MySQL Command-Line Client">
<span class="command">
<strong>
mysql
</strong>
</span>
</a>
process, rather than multiple
connections. For example:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa14076922"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token prompt">$> </span><span class="token command">mysqlbinlog</span> copied-binlog<span class="token punctuation">.</span>000001 copied-binlog<span class="token punctuation">.</span>000002 | mysql <span class="token property">-u</span> root <span class="token property">-p</span></code></pre>
</div>
<p>
For more information, see
<a class="xref" href="mysqlbinlog-backup.html" title="6.6.9.3 Using mysqlbinlog to Back Up Binary Log Files">
Section 6.6.9.3, “Using mysqlbinlog to Back Up Binary Log Files”
</a>
.
</p>
</li>
</ol>
</div>
</dd>
</dl>
</div>
<p>
This method has the advantage that a new server is available
almost immediately; only those transactions that were committed
while the snapshot or dump file was being replayed still need to
be obtained from the existing source. This means that the
replica's availability is not instantaneous, but only a
relatively short amount of time should be required for the replica
to catch up with these few remaining transactions.
</p>
<p>
Copying over binary logs to the target server in advance is
usually faster than reading the entire transaction execution
history from the source in real time. However, it may not always
be feasible to move these files to the target when required, due
to size or other considerations. The two remaining methods for
provisioning a new replica discussed in this section use other
means to transfer information about transactions to the new
replica.
</p>
<p>
<a name="replication-gtids-failover-empty">
</a>
<b>
Injecting empty transactions.
</b>
The source's global
<a class="link" href="replication-options-gtids.html#sysvar_gtid_executed">
<code class="literal">
gtid_executed
</code>
</a>
variable contains
the set of all transactions executed on the source. Rather than
copy the binary logs when taking a snapshot to provision a new
server, you can instead note the content of
<code class="literal">
gtid_executed
</code>
on the server from which the
snapshot was taken. Before adding the new server to the
replication chain, simply commit an empty transaction on the new
server for each transaction identifier contained in the
source's
<code class="literal">
gtid_executed
</code>
, like this:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa67814831"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SET</span> GTID_NEXT<span class="token operator">=</span><span class="token string">'aaa-bbb-ccc-ddd:N'</span><span class="token punctuation">;</span>
<span class="token keyword">BEGIN</span><span class="token punctuation">;</span>
<span class="token keyword">COMMIT</span><span class="token punctuation">;</span>
<span class="token keyword">SET</span> GTID_NEXT<span class="token operator">=</span><span class="token string">'AUTOMATIC'</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
Once all transaction identifiers have been reinstated in this way
using empty transactions, you must flush and purge the
replica's binary logs, as shown here, where
<em class="replaceable">
<code>
N
</code>
</em>
is the nonzero suffix of the current
binary log file name:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa21385560"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">FLUSH</span> <span class="token keyword">LOGS</span><span class="token punctuation">;</span>
<span class="token keyword">PURGE</span> <span class="token datatype">BINARY</span> <span class="token keyword">LOGS</span> <span class="token keyword">TO</span> <span class="token string">'source-bin.00000<em class="replaceable">N</em>'</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
You should do this to prevent this server from flooding the
replication stream with false transactions in the event that it is
later promoted to the source. (The
<a class="link" href="flush.html#flush-logs">
<code class="literal">
FLUSH
LOGS
</code>
</a>
statement forces the creation of a new binary log
file;
<a class="link" href="purge-binary-logs.html" title="15.4.1.1 PURGE BINARY LOGS Statement">
<code class="literal">
PURGE BINARY LOGS
</code>
</a>
purges the
empty transactions, but retains their identifiers.)
</p>
<p>
This method creates a server that is essentially a snapshot, but
in time is able to become a source as its binary log history
converges with that of the replication stream (that is, as it
catches up with the source or sources). This outcome is similar in
effect to that obtained using the remaining provisioning method,
which we discuss in the next few paragraphs.
</p>
<p>
<a name="replication-gtids-failover-gtid-purged">
</a>
<b>
Excluding transactions with gtid_purged.
</b>
The source's global
<a class="link" href="replication-options-gtids.html#sysvar_gtid_purged">
<code class="literal">
gtid_purged
</code>
</a>
variable contains
the set of all transactions that have been purged from the
source's binary log. As with the method discussed
previously (see
<a class="xref" href="replication-gtids-failover.html#replication-gtids-failover-empty" title="Injecting empty transactions">
Injecting empty transactions
</a>
), you can
record the value of
<a class="link" href="replication-options-gtids.html#sysvar_gtid_executed">
<code class="literal">
gtid_executed
</code>
</a>
on the server
from which the snapshot was taken (in place of copying the
binary logs to the new server). Unlike the previous method,
there is no need to commit empty transactions (or to issue
<a class="link" href="purge-binary-logs.html" title="15.4.1.1 PURGE BINARY LOGS Statement">
<code class="literal">
PURGE BINARY LOGS
</code>
</a>
); instead, you
can set
<a class="link" href="replication-options-gtids.html#sysvar_gtid_purged">
<code class="literal">
gtid_purged
</code>
</a>
on the
replica directly, based on the value of
<a class="link" href="replication-options-gtids.html#sysvar_gtid_executed">
<code class="literal">
gtid_executed
</code>
</a>
on the server
from which the backup or snapshot was taken.
</p>
<p>
As with the method using empty transactions, this method creates a
server that is functionally a snapshot, but in time is able to
become a source as its binary log history converges with that of
the source and other replicas.
</p>
<p>
<a name="replication-gtids-restoring-mysqlbinlog">
</a>
<b>
Restoring GTID mode replicas.
</b>
When restoring a replica in a GTID based replication setup that
has encountered an error, injecting an empty transaction may not
solve the problem because an event does not have a GTID.
</p>
<p>
Use
<a class="link" href="mysqlbinlog.html" title="6.6.9 mysqlbinlog — Utility for Processing Binary Log Files">
<span class="command">
<strong>
mysqlbinlog
</strong>
</span>
</a>
to find the next transaction,
which is probably the first transaction in the next log file after
the event. Copy everything up to the
<code class="literal">
COMMIT
</code>
for
that transaction, being sure to include the
<code class="literal">
SET
@@SESSION.gtid_next
</code>
. Even if you are not using row-based
replication, you can still run binary log row events in the
command line client.
</p>
<p>
Stop the replica and run the transaction you copied. The
<a class="link" href="mysqlbinlog.html" title="6.6.9 mysqlbinlog — Utility for Processing Binary Log Files">
<span class="command">
<strong>
mysqlbinlog
</strong>
</span>
</a>
output sets the delimiter to
<code class="literal">
/*!*/;
</code>
, so set it back to the default, like
this:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa67197612"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">DELIMITER</span> <span class="token punctuation">;</span></code></pre>
</div>
<p>
Restart replication from the correct position automatically:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa37607622"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SET</span> gtid_next<span class="token operator">=</span>AUTOMATIC<span class="token punctuation">;</span>
<span class="token prompt">mysql></span> <span class="token keyword">RESET</span> <span class="token keyword">REPLICA</span><span class="token punctuation">;</span>
<span class="token prompt">mysql></span> <span class="token keyword">START</span> <span class="token keyword">REPLICA</span><span class="token punctuation">;</span></code></pre>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/gis-class-polygon.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="gis-class-polygon">
</a>
13.4.2.7 Polygon Class
</h4>
</div>
</div>
</div>
<p>
A
<code class="literal">
Polygon
</code>
is a planar
<code class="literal">
Surface
</code>
representing a multisided geometry.
It is defined by a single exterior boundary and zero or more
interior boundaries, where each interior boundary defines a
hole in the
<code class="literal">
Polygon
</code>
.
</p>
<p>
<span class="bold">
<strong>
<code class="literal">
Polygon
</code>
Examples
</strong>
</span>
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
On a region map,
<code class="literal">
Polygon
</code>
objects could
represent forests, districts, and so on.
</p>
</li>
</ul>
</div>
<p>
<span class="bold">
<strong>
<code class="literal">
Polygon
</code>
Assertions
</strong>
</span>
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
The boundary of a
<code class="literal">
Polygon
</code>
consists of a
set of
<code class="literal">
LinearRing
</code>
objects (that is,
<code class="literal">
LineString
</code>
objects that are both simple
and closed) that make up its exterior and interior
boundaries.
</p>
</li>
<li class="listitem">
<p>
A
<code class="literal">
Polygon
</code>
has no rings that cross. The
rings in the boundary of a
<code class="literal">
Polygon
</code>
may
intersect at a
<code class="literal">
Point
</code>
, but only as a
tangent.
</p>
</li>
<li class="listitem">
<p>
A
<code class="literal">
Polygon
</code>
has no lines, spikes, or
punctures.
</p>
</li>
<li class="listitem">
<p>
A
<code class="literal">
Polygon
</code>
has an interior that is a
connected point set.
</p>
</li>
<li class="listitem">
<p>
A
<code class="literal">
Polygon
</code>
may have holes. The exterior
of a
<code class="literal">
Polygon
</code>
with holes is not
connected. Each hole defines a connected component of the
exterior.
</p>
</li>
</ul>
</div>
<p>
The preceding assertions make a
<code class="literal">
Polygon
</code>
a
simple geometry.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/restart.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="restart">
</a>
15.7.8.8 RESTART Statement
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045168295136">
</a>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa69717273"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">RESTART</span></code></pre>
</div>
<p>
This statement stops and restarts the MySQL server. It requires
the
<a class="link" href="privileges-provided.html#priv_shutdown">
<code class="literal">
SHUTDOWN
</code>
</a>
privilege.
</p>
<p>
One use for
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
is when it is
not possible or convenient to gain command-line access to the
MySQL server on the server host to restart it. For example,
<a class="link" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
<code class="literal">
SET
PERSIST_ONLY
</code>
</a>
can be used at runtime to make
configuration changes to system variables that can be set only
at server startup, but the server must still be restarted for
those changes to take effect. The
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
statement provides a way
to do so from within client sessions, without requiring
command-line access on the server host.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
After executing a
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
statement, the client can expect the current connection to be
lost. If auto-reconnect is enabled, the connection is
reestablished after the server restarts. Otherwise, the
connection must be reestablished manually.
</p>
</div>
<p>
A successful
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
operation
requires
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
to be running in an
environment that has a monitoring process available to detect a
server shutdown performed for restart purposes:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
In the presence of a monitoring process,
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
causes
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
to terminate such that the
monitoring process can determine that it should start a new
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
instance.
</p>
</li>
<li class="listitem">
<p>
If no monitoring process is present,
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
fails with an error.
</p>
</li>
</ul>
</div>
<p>
These platforms provide the necessary monitoring support for the
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
statement:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Windows, when
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
is started as a
Windows service or standalone. (
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
forks, and one process acts as a monitor to the other, which
acts as the server.)
</p>
</li>
<li class="listitem">
<p>
Unix and Unix-like systems that use systemd or
<a class="link" href="mysqld-safe.html" title="6.3.2 mysqld_safe — MySQL Server Startup Script">
<span class="command">
<strong>
mysqld_safe
</strong>
</span>
</a>
to manage
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
.
</p>
</li>
</ul>
</div>
<p>
To configure a monitoring environment such that
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
enables the
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
statement:
</p>
<div class="orderedlist">
<ol class="orderedlist" type="1">
<li class="listitem">
<p>
Set the
<code class="literal">
MYSQLD_PARENT_PID
</code>
environment
variable to the value of the process ID of the process that
starts
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
, before starting
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
.
</p>
</li>
<li class="listitem">
<p>
When
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
performs a shutdown due to
use of the
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
statement,
it returns exit code 16.
</p>
</li>
<li class="listitem">
<p>
When the monitoring process detects an exit code of 16, it
starts
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
again. Otherwise, it exits.
</p>
</li>
</ol>
</div>
<p>
Here is a minimal example as implemented in the
<span class="command">
<strong>
bash
</strong>
</span>
shell:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-terminal"><div class="docs-select-all right" id="sa5682772"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token comment" spellcheck="true">#!/bin/bash</span>
export MYSQLD_PARENT_PID<span class="token attr-value"><span class="token punctuation">=</span>$$</span>
export MYSQLD_RESTART_EXIT<span class="token attr-value"><span class="token punctuation">=</span>16</span>
while true <span class="token punctuation">;</span> do
bin/mysqld <em class="replaceable">mysqld options here</em>
if <span class="token punctuation">[</span> $? <span class="token property">-ne</span> $MYSQLD_RESTART_EXIT <span class="token punctuation">]</span><span class="token punctuation">;</span> then
break
fi
done</code></pre>
</div>
<p>
On Windows, the forking used to implement
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
makes determining the
server process to attach to for debugging more difficult. To
alleviate this, starting the server with
<a class="link" href="server-options.html#option_mysqld_gdb">
<code class="option">
--gdb
</code>
</a>
suppresses forking, in
addition to its other actions done to set up a debugging
environment. In non-debug settings,
<a class="link" href="server-options.html#option_mysqld_no-monitor">
<code class="option">
--no-monitor
</code>
</a>
may be used for the
sole purpose of suppressing forking the monitor process. For a
server started with either
<a class="link" href="server-options.html#option_mysqld_gdb">
<code class="option">
--gdb
</code>
</a>
or
<a class="link" href="server-options.html#option_mysqld_no-monitor">
<code class="option">
--no-monitor
</code>
</a>
, executing
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
causes the server to
simply exit without restarting.
</p>
<p>
The
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
<code class="literal">
Com_restart
</code>
</a>
status variable tracks the number of
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
statements. Because
status variables are initialized for each server startup and do
not persist across restarts,
<code class="literal">
Com_restart
</code>
normally has a value of zero, but can be nonzero if
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
statements were executed
but failed.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/information-schema-schema-privileges-table.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="information-schema-schema-privileges-table">
</a>
28.3.33 The INFORMATION_SCHEMA SCHEMA_PRIVILEGES Table
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045078715120">
</a>
<p>
The
<a class="link" href="information-schema-schema-privileges-table.html" title="28.3.33 The INFORMATION_SCHEMA SCHEMA_PRIVILEGES Table">
<code class="literal">
SCHEMA_PRIVILEGES
</code>
</a>
table provides
information about schema (database) privileges. It takes its
values from the
<code class="literal">
mysql.db
</code>
system table.
</p>
<p>
The
<a class="link" href="information-schema-schema-privileges-table.html" title="28.3.33 The INFORMATION_SCHEMA SCHEMA_PRIVILEGES Table">
<code class="literal">
SCHEMA_PRIVILEGES
</code>
</a>
table has these
columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
GRANTEE
</code>
</p>
<p>
The name of the account to which the privilege is granted, in
<code class="literal">
'
<em class="replaceable">
<code>
user_name
</code>
</em>
'@'
<em class="replaceable">
<code>
host_name
</code>
</em>
'
</code>
format.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
TABLE_CATALOG
</code>
</p>
<p>
The name of the catalog to which the schema belongs. This
value is always
<code class="literal">
def
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
TABLE_SCHEMA
</code>
</p>
<p>
The name of the schema.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
PRIVILEGE_TYPE
</code>
</p>
<p>
The privilege granted. The value can be any privilege that can
be granted at the schema level; see
<a class="xref" href="grant.html" title="15.7.1.6 GRANT Statement">
Section 15.7.1.6, “GRANT Statement”
</a>
.
Each row lists a single privilege, so there is one row per
schema privilege held by the grantee.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
IS_GRANTABLE
</code>
</p>
<p>
<code class="literal">
YES
</code>
if the user has the
<a class="link" href="privileges-provided.html#priv_grant-option">
<code class="literal">
GRANT OPTION
</code>
</a>
privilege,
<code class="literal">
NO
</code>
otherwise. The output does not list
<a class="link" href="privileges-provided.html#priv_grant-option">
<code class="literal">
GRANT OPTION
</code>
</a>
as a separate row
with
<code class="literal">
PRIVILEGE_TYPE='GRANT OPTION'
</code>
.
</p>
</li>
</ul>
</div>
<h4>
<a name="idm46045078691712">
</a>
Notes
</h4>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="link" href="information-schema-schema-privileges-table.html" title="28.3.33 The INFORMATION_SCHEMA SCHEMA_PRIVILEGES Table">
<code class="literal">
SCHEMA_PRIVILEGES
</code>
</a>
is a
nonstandard
<code class="literal">
INFORMATION_SCHEMA
</code>
table.
</p>
</li>
</ul>
</div>
<p>
The following statements are
<span class="emphasis">
<em>
not
</em>
</span>
equivalent:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa20975243"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token keyword">FROM</span> INFORMATION_SCHEMA<span class="token punctuation">.</span>SCHEMA_PRIVILEGES
<span class="token keyword">SHOW</span> <span class="token keyword">GRANTS</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span></code></pre>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-replication-group-members-table.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="performance-schema-replication-group-members-table">
</a>
29.12.11.16 The replication_group_members Table
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045070710720">
</a>
<a class="indexterm" name="idm46045070709216">
</a>
<p>
This table shows network and status information for
replication group members. The network addresses shown are the
addresses used to connect clients to the group, and should not
be confused with the member's internal group
communication address specified by
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_local_address">
<code class="literal">
group_replication_local_address
</code>
</a>
.
</p>
<p>
The
<a class="link" href="performance-schema-replication-group-members-table.html" title="29.12.11.16 The replication_group_members Table">
<code class="literal">
replication_group_members
</code>
</a>
table has these columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
CHANNEL_NAME
</code>
</p>
<p>
Name of the Group Replication channel.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
MEMBER_ID
</code>
</p>
<p>
The member server UUID. This has a different value for
each member in the group. This also serves as a key
because it is unique to each member.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
MEMBER_HOST
</code>
</p>
<p>
Network address of this member (host name or IP address).
Retrieved from the member's
<a class="link" href="server-system-variables.html#sysvar_hostname">
<code class="literal">
hostname
</code>
</a>
variable. This
is the address which clients connect to, unlike the
group_replication_local_address which is used for internal
group communication.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
MEMBER_PORT
</code>
</p>
<p>
Port on which the server is listening. Retrieved from the
member's
<a class="link" href="server-system-variables.html#sysvar_port">
<code class="literal">
port
</code>
</a>
variable.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
MEMBER_STATE
</code>
</p>
<p>
Current state of this member; can be any one of the
following:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
<code class="literal">
ONLINE
</code>
: The member is in a fully
functioning state.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
RECOVERING
</code>
: The server has joined a
group from which it is retrieving data.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
OFFLINE
</code>
: The group replication
plugin is installed but has not been started.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
ERROR
</code>
: The member has encountered
an error, either during applying transactions or
during the recovery phase, and is not participating in
the group's transactions.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
UNREACHABLE
</code>
: The failure detection
process suspects that this member cannot be contacted,
because the group messages have timed out.
</p>
</li>
</ul>
</div>
<p>
See
<a class="xref" href="group-replication-server-states.html" title="20.4.2 Group Replication Server States">
Section 20.4.2, “Group Replication Server States”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
MEMBER_ROLE
</code>
</p>
<p>
Role of the member in the group, either
<code class="literal">
PRIMARY
</code>
or
<code class="literal">
SECONDARY
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
MEMBER_VERSION
</code>
</p>
<p>
MySQL version of the member.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
MEMBER_COMMUNICATION_STACK
</code>
</p>
<p>
The communication stack used for the group, either the
<code class="literal">
XCOM
</code>
communication stack or the
<code class="literal">
MYSQL
</code>
communication stack.
</p>
</li>
</ul>
</div>
<p>
The
<a class="link" href="performance-schema-replication-group-members-table.html" title="29.12.11.16 The replication_group_members Table">
<code class="literal">
replication_group_members
</code>
</a>
table has no indexes.
</p>
<p>
<a class="link" href="truncate-table.html" title="15.1.37 TRUNCATE TABLE Statement">
<code class="literal">
TRUNCATE TABLE
</code>
</a>
is not permitted
for the
<a class="link" href="performance-schema-replication-group-members-table.html" title="29.12.11.16 The replication_group_members Table">
<code class="literal">
replication_group_members
</code>
</a>
table.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/common-errors.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="common-errors">
</a>
B.3.2 Common Errors When Using MySQL Programs
</h3>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="error-access-denied.html">
B.3.2.1 Access denied
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="can-not-connect-to-server.html">
B.3.2.2 Can't connect to [local] MySQL server
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="error-lost-connection.html">
B.3.2.3 Lost connection to MySQL server
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="password-too-long.html">
B.3.2.4 Password Fails When Entered Interactively
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="too-many-connections.html">
B.3.2.5 Too many connections
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="out-of-memory.html">
B.3.2.6 Out of memory
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="gone-away.html">
B.3.2.7 MySQL server has gone away
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="packet-too-large.html">
B.3.2.8 Packet Too Large
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="communication-errors.html">
B.3.2.9 Communication Errors and Aborted Connections
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="full-table.html">
B.3.2.10 The table is full
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="cannot-create.html">
B.3.2.11 Can't create/write to file
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="commands-out-of-sync.html">
B.3.2.12 Commands out of sync
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="ignoring-user.html">
B.3.2.13 Ignoring user
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="cannot-find-table.html">
B.3.2.14 Table 'tbl_name' doesn't exist
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="cannot-initialize-character-set.html">
B.3.2.15 Can't initialize character set
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="not-enough-file-handles.html">
B.3.2.16 File Not Found and Similar Errors
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="table-corruption.html">
B.3.2.17 Table-Corruption Issues
</a>
</span>
</dt>
</dl>
</div>
<a class="indexterm" name="idm46045054592976">
</a>
<p>
This section lists some errors that users frequently encounter
when running MySQL programs. Although the problems show up when
you try to run client programs, the solutions to many of the
problems involves changing the configuration of the MySQL
server.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/server-configuration.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="server-configuration">
</a>
7.1.1 Configuring the Server
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045302467040">
</a>
<a class="indexterm" name="idm46045302465968">
</a>
<a class="indexterm" name="idm46045302464480">
</a>
<a class="indexterm" name="idm46045302462992">
</a>
<p>
The MySQL server,
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
, has many command
options and system variables that can be set at startup to
configure its operation. To determine the default command option
and system variable values used by the server, execute this
command:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa48148092"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token prompt">$> </span><span class="token command">mysqld</span> <span class="token property">--verbose</span> <span class="token property">--help</span></code></pre>
</div>
<a class="indexterm" name="idm46045302458384">
</a>
<a class="indexterm" name="idm46045302457312">
</a>
<a class="indexterm" name="idm46045302456240">
</a>
<a class="indexterm" name="idm46045302454752">
</a>
<p>
The command produces a list of all
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
options and configurable system variables. Its output includes the
default option and variable values and looks something like this:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-terminal"><div class="docs-select-all right" id="sa86480337"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal">activate-all-roles-on-login FALSE
admin-address <span class="token punctuation">(</span>No default value<span class="token punctuation">)</span>
admin-port 33062
admin-ssl TRUE
admin-ssl-ca <span class="token punctuation">(</span>No default value<span class="token punctuation">)</span>
admin-ssl-capath <span class="token punctuation">(</span>No default value<span class="token punctuation">)</span>
admin-ssl-cert <span class="token punctuation">(</span>No default value<span class="token punctuation">)</span>
admin-ssl-cipher <span class="token punctuation">(</span>No default value<span class="token punctuation">)</span>
admin-ssl-crl <span class="token punctuation">(</span>No default value<span class="token punctuation">)</span>
<span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span>
transaction-prealloc-size 4096
transaction-read-only FALSE
updatable-views-with-limit YES
upgrade AUTO
validate-config FALSE
validate-user-plugins TRUE
verbose TRUE
wait-timeout 28800
windowing-use-high-precision TRUE
xa-detach-on-prepare TRUE</code></pre>
</div>
<p>
To see the current system variable values actually used by the
server as it runs, connect to it and execute this statement:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa84296113"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SHOW</span> <span class="token keyword">VARIABLES</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
To see some statistical and status indicators for a running
server, execute this statement:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa45521588"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SHOW</span> <span class="token keyword">STATUS</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
System variable and status information also is available using the
<a class="link" href="mysqladmin.html" title="6.5.2 mysqladmin — A MySQL Server Administration Program">
<span class="command">
<strong>
mysqladmin
</strong>
</span>
</a>
command:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-terminal"><div class="docs-select-all right" id="sa92210142"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token prompt">$> </span><span class="token command">mysqladmin</span> variables
<span class="token prompt">$> </span><span class="token command">mysqladmin</span> extended-status</code></pre>
</div>
<p>
For a full description of all command options, system variables,
and status variables, see these sections:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="xref" href="server-options.html" title="7.1.7 Server Command Options">
Section 7.1.7, “Server Command Options”
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="server-status-variables.html" title="7.1.10 Server Status Variables">
Section 7.1.10, “Server Status Variables”
</a>
</p>
</li>
</ul>
</div>
<p>
More detailed monitoring information is available from the
Performance Schema; see
<a class="xref" href="performance-schema.html" title="Chapter 29 MySQL Performance Schema">
Chapter 29,
<i>
MySQL Performance Schema
</i>
</a>
. In
addition, the MySQL
<code class="literal">
sys
</code>
schema is a set of
objects that provides convenient access to data collected by the
Performance Schema; see
<a class="xref" href="sys-schema.html" title="Chapter 30 MySQL sys Schema">
Chapter 30,
<i>
MySQL sys Schema
</i>
</a>
.
</p>
<p>
If you specify an option on the command line for
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
or
<a class="link" href="mysqld-safe.html" title="6.3.2 mysqld_safe — MySQL Server Startup Script">
<span class="command">
<strong>
mysqld_safe
</strong>
</span>
</a>
, it
remains in effect only for that invocation of the server. To use
the option every time the server runs, put it in an option file.
See
<a class="xref" href="option-files.html" title="6.2.2.2 Using Option Files">
Section 6.2.2.2, “Using Option Files”
</a>
.
</p>
<p>
Windows users may execute
<a class="xref" href="mysql-configurator.html" title="2.3.2 Configuration: Using MySQL Configurator">
Section 2.3.2, “Configuration: Using MySQL Configurator”
</a>
to
help configure a MySQL server installation. This includes tasks
such as configuring MySQL users, log files, the Windows service
name, and sample databases.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-ndbinfo-counters.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="mysql-cluster-ndbinfo-counters">
</a>
25.6.17.13 The ndbinfo counters Table
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045090132512">
</a>
<p>
The
<code class="literal">
counters
</code>
table provides running totals of
events such as reads and writes for specific kernel blocks and
data nodes. Counts are kept from the most recent node start or
restart; a node start or restart resets all counters on that
node. Not all kernel blocks have all types of counters.
</p>
<p>
The
<code class="literal">
counters
</code>
table contains the following
columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
node_id
</code>
</p>
<p>
The data node ID
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
block_name
</code>
</p>
<p>
Name of the associated NDB kernel block (see
<a class="ulink" href="/doc/ndb-internals/en/ndb-internals-kernel-blocks.html" target="_top">
NDB Kernel Blocks
</a>
).
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
block_instance
</code>
</p>
<p>
Block instance
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
counter_id
</code>
</p>
<p>
The counter's internal ID number; normally an integer
between 1 and 10, inclusive.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
counter_name
</code>
</p>
<p>
The name of the counter. See text for names of individual
counters and the NDB kernel block with which each counter is
associated.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
val
</code>
</p>
<p>
The counter's value
</p>
</li>
</ul>
</div>
<h5>
<a name="idm46045090115664">
</a>
Notes
</h5>
<p>
Each counter is associated with a particular NDB kernel block.
</p>
<p>
The
<code class="literal">
OPERATIONS
</code>
counter is associated with the
<a class="ulink" href="/doc/ndb-internals/en/ndb-internals-kernel-blocks-dblqh.html" target="_top">
<code class="literal">
DBLQH
</code>
</a>
(local query handler)
kernel block. A primary-key read counts as one operation, as
does a primary-key update. For reads, there is one operation in
<a class="ulink" href="/doc/ndb-internals/en/ndb-internals-kernel-blocks-dblqh.html" target="_top">
<code class="literal">
DBLQH
</code>
</a>
per operation in
<a class="ulink" href="/doc/ndb-internals/en/ndb-internals-kernel-blocks-dbtc.html" target="_top">
<code class="literal">
DBTC
</code>
</a>
. For writes, there is
one operation counted per fragment replica.
</p>
<p>
The
<code class="literal">
ATTRINFO
</code>
,
<code class="literal">
TRANSACTIONS
</code>
,
<code class="literal">
COMMITS
</code>
,
<code class="literal">
READS
</code>
,
<code class="literal">
LOCAL_READS
</code>
,
<code class="literal">
SIMPLE_READS
</code>
,
<code class="literal">
WRITES
</code>
,
<code class="literal">
LOCAL_WRITES
</code>
,
<code class="literal">
ABORTS
</code>
,
<code class="literal">
TABLE_SCANS
</code>
, and
<code class="literal">
RANGE_SCANS
</code>
counters are associated with the
<a class="ulink" href="/doc/ndb-internals/en/ndb-internals-kernel-blocks-dbtc.html" target="_top">
<code class="literal">
DBTC
</code>
</a>
(transaction
co-ordinator) kernel block.
</p>
<p>
<code class="literal">
LOCAL_WRITES
</code>
and
<code class="literal">
LOCAL_READS
</code>
are primary-key operations using
a transaction coordinator in a node that also holds the primary
fragment replica of the record.
</p>
<p>
The
<code class="literal">
READS
</code>
counter includes all reads.
<code class="literal">
LOCAL_READS
</code>
includes only those reads of the
primary fragment replica on the same node as this transaction
coordinator.
<code class="literal">
SIMPLE_READS
</code>
includes only those
reads in which the read operation is the beginning and ending
operation for a given transaction. Simple reads do not hold
locks but are part of a transaction, in that they observe
uncommitted changes made by the transaction containing them but
not of any other uncommitted transactions. Such reads are
<span class="quote">
“
<span class="quote">
simple
</span>
”
</span>
from the point of view of the TC block;
since they hold no locks they are not durable, and once
<a class="ulink" href="/doc/ndb-internals/en/ndb-internals-kernel-blocks-dbtc.html" target="_top">
<code class="literal">
DBTC
</code>
</a>
has routed them to the
relevant LQH block, it holds no state for them.
</p>
<p>
<code class="literal">
ATTRINFO
</code>
keeps a count of the number of times
an interpreted program is sent to the data node. See
<a class="ulink" href="/doc/ndb-internals/en/ndb-internals-ndb-protocol-messages.html" target="_top">
NDB Protocol Messages
</a>
, for more
information about
<code class="literal">
ATTRINFO
</code>
messages in the
<code class="literal">
NDB
</code>
kernel.
</p>
<p>
The
<code class="literal">
LOCAL_TABLE_SCANS_SENT
</code>
,
<code class="literal">
READS_RECEIVED
</code>
,
<code class="literal">
PRUNED_RANGE_SCANS_RECEIVED
</code>
,
<code class="literal">
RANGE_SCANS_RECEIVED
</code>
,
<code class="literal">
LOCAL_READS_SENT
</code>
,
<code class="literal">
CONST_PRUNED_RANGE_SCANS_RECEIVED
</code>
,
<code class="literal">
LOCAL_RANGE_SCANS_SENT
</code>
,
<code class="literal">
REMOTE_READS_SENT
</code>
,
<code class="literal">
REMOTE_RANGE_SCANS_SENT
</code>
,
<code class="literal">
READS_NOT_FOUND
</code>
,
<code class="literal">
SCAN_BATCHES_RETURNED
</code>
,
<code class="literal">
TABLE_SCANS_RECEIVED
</code>
, and
<code class="literal">
SCAN_ROWS_RETURNED
</code>
counters are associated
with the
<a class="ulink" href="/doc/ndb-internals/en/ndb-internals-kernel-blocks-dbspj.html" target="_top">
<code class="literal">
DBSPJ
</code>
</a>
(select
push-down join) kernel block.
</p>
<p>
The
<code class="literal">
block_name
</code>
and
<code class="literal">
block_instance
</code>
columns provide, respectively,
the applicable NDB kernel block name and instance number. You
can use these to obtain information about specific threads from
the
<a class="link" href="mysql-cluster-ndbinfo-threadblocks.html" title="25.6.17.62 The ndbinfo threadblocks Table">
<code class="literal">
threadblocks
</code>
</a>
table.
</p>
<p>
A number of counters provide information about transporter
overload and send buffer sizing when troubleshooting such
issues. For each LQH instance, there is one instance of each
counter in the following list:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
LQHKEY_OVERLOAD
</code>
: Number of primary key
requests rejected at the LQH block instance due to
transporter overload
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LQHKEY_OVERLOAD_TC
</code>
: Count of instances of
<code class="literal">
LQHKEY_OVERLOAD
</code>
where the TC node
transporter was overloaded
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LQHKEY_OVERLOAD_READER
</code>
: Count of
instances of
<code class="literal">
LQHKEY_OVERLOAD
</code>
where the
API reader (reads only) node was overloaded.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LQHKEY_OVERLOAD_NODE_PEER
</code>
: Count of
instances of
<code class="literal">
LQHKEY_OVERLOAD
</code>
where the
next backup data node (writes only) was overloaded
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LQHKEY_OVERLOAD_SUBSCRIBER
</code>
: Count of
instances of
<code class="literal">
LQHKEY_OVERLOAD
</code>
where a
event subscriber (writes only) was overloaded.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LQHSCAN_SLOWDOWNS
</code>
: Count of instances
where a fragment scan batch size was reduced due to scanning
API transporter overload.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/stored-program-variables.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="stored-program-variables">
</a>
15.6.4 Variables in Stored Programs
</h3>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="declare-local-variable.html">
15.6.4.1 Local Variable DECLARE Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="local-variable-scope.html">
15.6.4.2 Local Variable Scope and Resolution
</a>
</span>
</dt>
</dl>
</div>
<p>
System variables and user-defined variables can be used in stored
programs, just as they can be used outside stored-program context.
In addition, stored programs can use
<code class="literal">
DECLARE
</code>
to
define local variables, and stored routines (procedures and
functions) can be declared to take parameters that communicate
values between the routine and its caller.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
To declare local variables, use the
<a class="link" href="declare-local-variable.html" title="15.6.4.1 Local Variable DECLARE Statement">
<code class="literal">
DECLARE
</code>
</a>
statement, as described in
<a class="xref" href="declare-local-variable.html" title="15.6.4.1 Local Variable DECLARE Statement">
Section 15.6.4.1, “Local Variable DECLARE Statement”
</a>
.
</p>
</li>
<li class="listitem">
<p>
Variables can be set directly with the
<a class="link" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
<code class="literal">
SET
</code>
</a>
statement. See
<a class="xref" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
Section 15.7.6.1, “SET Syntax for Variable Assignment”
</a>
.
</p>
</li>
<li class="listitem">
<p>
Results from queries can be retrieved into local variables
using
<a class="link" href="select-into.html" title="15.2.13.1 SELECT ... INTO Statement">
<code class="literal">
SELECT ...
INTO
<em class="replaceable">
<code>
var_list
</code>
</em>
</code>
</a>
or by
opening a cursor and using
<a class="link" href="fetch.html" title="15.6.6.3 Cursor FETCH Statement">
<code class="literal">
FETCH ... INTO
<em class="replaceable">
<code>
var_list
</code>
</em>
</code>
</a>
. See
<a class="xref" href="select-into.html" title="15.2.13.1 SELECT ... INTO Statement">
Section 15.2.13.1, “SELECT ... INTO Statement”
</a>
, and
<a class="xref" href="cursors.html" title="15.6.6 Cursors">
Section 15.6.6, “Cursors”
</a>
.
</p>
</li>
</ul>
</div>
<p>
For information about the scope of local variables and how MySQL
resolves ambiguous names, see
<a class="xref" href="local-variable-scope.html" title="15.6.4.2 Local Variable Scope and Resolution">
Section 15.6.4.2, “Local Variable Scope and Resolution”
</a>
.
</p>
<p>
It is not permitted to assign the value
<code class="literal">
DEFAULT
</code>
to stored procedure or function parameters or stored program local
variables (for example with a
<code class="literal">
SET
<em class="replaceable">
<code>
var_name
</code>
</em>
= DEFAULT
</code>
statement). In MySQL 8.4, this results in a syntax
error.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/show-events.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="show-events">
</a>
15.7.7.19 SHOW EVENTS Statement
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045170440448">
</a>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa92524843"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SHOW</span> <span class="token keyword">EVENTS</span>
<span class="token punctuation">[</span>{<span class="token keyword">FROM</span> <span class="token operator">|</span> <span class="token keyword">IN</span>} <span class="token keyword"><em class="replaceable">schema_name</em></span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token operator">LIKE</span> <span class="token string">'<em class="replaceable">pattern</em>'</span> <span class="token operator">|</span> <span class="token keyword">WHERE</span> <em class="replaceable">expr</em><span class="token punctuation">]</span></code></pre>
</div>
<p>
This statement displays information about Event Manager events,
which are discussed in
<a class="xref" href="event-scheduler.html" title="27.4 Using the Event Scheduler">
Section 27.4, “Using the Event Scheduler”
</a>
. It
requires the
<a class="link" href="privileges-provided.html#priv_event">
<code class="literal">
EVENT
</code>
</a>
privilege for
the database from which the events are to be shown.
</p>
<p>
In its simplest form,
<a class="link" href="show-events.html" title="15.7.7.19 SHOW EVENTS Statement">
<code class="literal">
SHOW EVENTS
</code>
</a>
lists all of the events in the current schema:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa22929626"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token function">CURRENT_USER</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token function">SCHEMA</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> CURRENT_USER() <span class="token punctuation">|</span> SCHEMA() <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> jon@ghidora <span class="token punctuation">|</span> myschema <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output">1 row in set (0.00 sec)</span>
<span class="token prompt">mysql></span> <span class="token keyword">SHOW</span> <span class="token keyword">EVENTS</span>\G
<span class="token output"><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span> 1. row <span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span>
Db<span class="token punctuation">:</span> myschema
Name<span class="token punctuation">:</span> e_daily
Definer<span class="token punctuation">:</span> jon@ghidora
Time zone<span class="token punctuation">:</span> SYSTEM
Type<span class="token punctuation">:</span> RECURRING
Execute at<span class="token punctuation">:</span> NULL
Interval value<span class="token punctuation">:</span> 1
Interval field<span class="token punctuation">:</span> DAY
Starts<span class="token punctuation">:</span> 2018-08-08 11<span class="token punctuation">:</span>06<span class="token punctuation">:</span>34
Ends<span class="token punctuation">:</span> NULL
Status<span class="token punctuation">:</span> ENABLED
Originator<span class="token punctuation">:</span> 1
character_set_client<span class="token punctuation">:</span> utf8mb4
collation_connection<span class="token punctuation">:</span> utf8mb4_0900_ai_ci
Database Collation<span class="token punctuation">:</span> utf8mb4_0900_ai_ci</span></code></pre>
</div>
<p>
To see events for a specific schema, use the
<code class="literal">
FROM
</code>
clause. For example, to see events for
the
<code class="literal">
test
</code>
schema, use the following statement:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa57646886"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SHOW</span> <span class="token keyword">EVENTS</span> <span class="token keyword">FROM</span> test<span class="token punctuation">;</span></code></pre>
</div>
<p>
The
<a class="link" href="string-comparison-functions.html#operator_like">
<code class="literal">
LIKE
</code>
</a>
clause, if present,
indicates which event names to match. The
<code class="literal">
WHERE
</code>
clause can be given to select rows
using more general conditions, as discussed in
<a class="xref" href="extended-show.html" title="28.8 Extensions to SHOW Statements">
Section 28.8, “Extensions to SHOW Statements”
</a>
.
</p>
<p>
<a class="link" href="show-events.html" title="15.7.7.19 SHOW EVENTS Statement">
<code class="literal">
SHOW EVENTS
</code>
</a>
output has these
columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
Db
</code>
</p>
<p>
The name of the schema (database) to which the event
belongs.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Name
</code>
</p>
<p>
The name of the event.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Definer
</code>
</p>
<p>
The account of the user who created the event, in
<code class="literal">
'
<em class="replaceable">
<code>
user_name
</code>
</em>
'@'
<em class="replaceable">
<code>
host_name
</code>
</em>
'
</code>
format.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Time zone
</code>
</p>
<p>
The event time zone, which is the time zone used for
scheduling the event and that is in effect within the event
as it executes. The default value is
<code class="literal">
SYSTEM
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Type
</code>
</p>
<p>
The event repetition type, either
<code class="literal">
ONE
TIME
</code>
(transient) or
<code class="literal">
RECURRING
</code>
(repeating).
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Execute At
</code>
</p>
<p>
For a one-time event, this is the
<a class="link" href="datetime.html" title="13.2.2 The DATE, DATETIME, and TIMESTAMP Types">
<code class="literal">
DATETIME
</code>
</a>
value specified in
the
<code class="literal">
AT
</code>
clause of the
<a class="link" href="create-event.html" title="15.1.13 CREATE EVENT Statement">
<code class="literal">
CREATE EVENT
</code>
</a>
statement used
to create the event, or of the last
<a class="link" href="alter-event.html" title="15.1.3 ALTER EVENT Statement">
<code class="literal">
ALTER EVENT
</code>
</a>
statement that
modified the event. The value shown in this column reflects
the addition or subtraction of any
<code class="literal">
INTERVAL
</code>
value included in the event's
<code class="literal">
AT
</code>
clause. For example, if an event is
created using
<code class="literal">
ON SCHEDULE AT CURRENT_TIMESTAMP +
'1:6' DAY_HOUR
</code>
, and the event was created at
2018-02-09 14:05:30, the value shown in this column would be
<code class="literal">
'2018-02-10 20:05:30'
</code>
. If the event's
timing is determined by an
<code class="literal">
EVERY
</code>
clause
instead of an
<code class="literal">
AT
</code>
clause (that is, if the
event is recurring), the value of this column is
<code class="literal">
NULL
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Interval Value
</code>
</p>
<p>
For a recurring event, the number of intervals to wait
between event executions. For a transient event, the value
of this column is always
<code class="literal">
NULL
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Interval Field
</code>
</p>
<p>
The time units used for the interval which a recurring event
waits before repeating. For a transient event, the value of
this column is always
<code class="literal">
NULL
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Starts
</code>
</p>
<p>
The start date and time for a recurring event. This is
displayed as a
<a class="link" href="datetime.html" title="13.2.2 The DATE, DATETIME, and TIMESTAMP Types">
<code class="literal">
DATETIME
</code>
</a>
value, and is
<code class="literal">
NULL
</code>
if no start date and
time are defined for the event. For a transient event, this
column is always
<code class="literal">
NULL
</code>
. For a recurring
event whose definition includes a
<code class="literal">
STARTS
</code>
clause, this column contains the corresponding
<a class="link" href="datetime.html" title="13.2.2 The DATE, DATETIME, and TIMESTAMP Types">
<code class="literal">
DATETIME
</code>
</a>
value. As with the
<code class="literal">
Execute At
</code>
column, this value resolves
any expressions used. If there is no
<code class="literal">
STARTS
</code>
clause affecting the timing of the
event, this column is
<code class="literal">
NULL
</code>
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Ends
</code>
</p>
<p>
For a recurring event whose definition includes a
<code class="literal">
ENDS
</code>
clause, this column contains the
corresponding
<a class="link" href="datetime.html" title="13.2.2 The DATE, DATETIME, and TIMESTAMP Types">
<code class="literal">
DATETIME
</code>
</a>
value.
As with the
<code class="literal">
Execute At
</code>
column, this value
resolves any expressions used. If there is no
<code class="literal">
ENDS
</code>
clause affecting the timing of the
event, this column is
<code class="literal">
NULL
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Status
</code>
</p>
<p>
The event status. One of
<code class="literal">
ENABLED
</code>
,
<code class="literal">
DISABLED
</code>
, or
<code class="literal">
REPLICA_SIDE_DISABLED
</code>
.
<code class="literal">
REPLICA_SIDE_DISABLED
</code>
indicates that the
creation of the event occurred on another MySQL server
acting as a replication source and replicated to the current
MySQL server which is acting as a replica, but the event is
not presently being executed on the replica. For more
information, see
<a class="xref" href="replication-features-invoked.html" title="19.5.1.16 Replication of Invoked Features">
Section 19.5.1.16, “Replication of Invoked Features”
</a>
. information.
</p>
<p>
<code class="literal">
REPLICA_SIDE_DISABLED
</code>
replaces
<code class="literal">
SLAVESIDE_DISABLED
</code>
, which is now
deprecated and subject to removal in a future version of
MySQL.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Originator
</code>
</p>
<p>
The server ID of the MySQL server on which the event was
created; used in replication. This value may be updated by
<a class="link" href="alter-event.html" title="15.1.3 ALTER EVENT Statement">
<code class="literal">
ALTER EVENT
</code>
</a>
to the server ID
of the server on which that statement occurs, if executed on
a source server. The default value is 0.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
character_set_client
</code>
</p>
<p>
The session value of the
<a class="link" href="server-system-variables.html#sysvar_character_set_client">
<code class="literal">
character_set_client
</code>
</a>
system
variable when the event was created.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
collation_connection
</code>
</p>
<p>
The session value of the
<a class="link" href="server-system-variables.html#sysvar_collation_connection">
<code class="literal">
collation_connection
</code>
</a>
system
variable when the event was created.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Database Collation
</code>
</p>
<p>
The collation of the database with which the event is
associated.
</p>
</li>
</ul>
</div>
<p>
For more information about
<code class="literal">
REPLICA_SIDE_DISABLED
</code>
and the
<code class="literal">
Originator
</code>
column, see
<a class="xref" href="replication-features-invoked.html" title="19.5.1.16 Replication of Invoked Features">
Section 19.5.1.16, “Replication of Invoked Features”
</a>
.
</p>
<p>
Times displayed by
<a class="link" href="show-events.html" title="15.7.7.19 SHOW EVENTS Statement">
<code class="literal">
SHOW EVENTS
</code>
</a>
are given in the event time zone, as discussed in
<a class="xref" href="events-metadata.html" title="27.4.4 Event Metadata">
Section 27.4.4, “Event Metadata”
</a>
.
</p>
<p>
Event information is also available from the
<code class="literal">
INFORMATION_SCHEMA
</code>
<a class="link" href="information-schema-events-table.html" title="28.3.14 The INFORMATION_SCHEMA EVENTS Table">
<code class="literal">
EVENTS
</code>
</a>
table. See
<a class="xref" href="information-schema-events-table.html" title="28.3.14 The INFORMATION_SCHEMA EVENTS Table">
Section 28.3.14, “The INFORMATION_SCHEMA EVENTS Table”
</a>
.
</p>
<p>
The event action statement is not shown in the output of
<a class="link" href="show-events.html" title="15.7.7.19 SHOW EVENTS Statement">
<code class="literal">
SHOW EVENTS
</code>
</a>
. Use
<a class="link" href="show-create-event.html" title="15.7.7.8 SHOW CREATE EVENT Statement">
<code class="literal">
SHOW CREATE EVENT
</code>
</a>
or the
<code class="literal">
INFORMATION_SCHEMA
</code>
<a class="link" href="information-schema-events-table.html" title="28.3.14 The INFORMATION_SCHEMA EVENTS Table">
<code class="literal">
EVENTS
</code>
</a>
table.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/error-access-denied.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="error-access-denied">
</a>
B.3.2.1 Access denied
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045054589728">
</a>
<a class="indexterm" name="idm46045054588240">
</a>
<a class="indexterm" name="idm46045054586752">
</a>
<p>
An
<code class="literal">
Access denied
</code>
error can have many
causes. Often the problem is related to the MySQL accounts
that the server permits client programs to use when
connecting. See
<a class="xref" href="access-control.html" title="8.2 Access Control and Account Management">
Section 8.2, “Access Control and Account Management”
</a>
, and
<a class="xref" href="problems-connecting.html" title="8.2.22 Troubleshooting Problems Connecting to MySQL">
Section 8.2.22, “Troubleshooting Problems Connecting to MySQL”
</a>
.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/information-schema-key-column-usage-table.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="information-schema-key-column-usage-table">
</a>
28.3.16 The INFORMATION_SCHEMA KEY_COLUMN_USAGE Table
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045079588928">
</a>
<p>
The
<a class="link" href="information-schema-key-column-usage-table.html" title="28.3.16 The INFORMATION_SCHEMA KEY_COLUMN_USAGE Table">
<code class="literal">
KEY_COLUMN_USAGE
</code>
</a>
table describes
which key columns have constraints. This table provides no
information about functional key parts because they are
expressions and the table provides information only about columns.
</p>
<p>
The
<a class="link" href="information-schema-key-column-usage-table.html" title="28.3.16 The INFORMATION_SCHEMA KEY_COLUMN_USAGE Table">
<code class="literal">
KEY_COLUMN_USAGE
</code>
</a>
table has these
columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
CONSTRAINT_CATALOG
</code>
</p>
<p>
The name of the catalog to which the constraint belongs. This
value is always
<code class="literal">
def
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
CONSTRAINT_SCHEMA
</code>
</p>
<p>
The name of the schema (database) to which the constraint
belongs.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
CONSTRAINT_NAME
</code>
</p>
<p>
The name of the constraint.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
TABLE_CATALOG
</code>
</p>
<p>
The name of the catalog to which the table belongs. This value
is always
<code class="literal">
def
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
TABLE_SCHEMA
</code>
</p>
<p>
The name of the schema (database) to which the table belongs.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
TABLE_NAME
</code>
</p>
<p>
The name of the table that has the constraint.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
COLUMN_NAME
</code>
</p>
<p>
The name of the column that has the constraint.
</p>
<p>
If the constraint is a foreign key, then this is the column of
the foreign key, not the column that the foreign key
references.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
ORDINAL_POSITION
</code>
</p>
<p>
The column's position within the constraint, not the column's
position within the table. Column positions are numbered
beginning with 1.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
POSITION_IN_UNIQUE_CONSTRAINT
</code>
</p>
<p>
<code class="literal">
NULL
</code>
for unique and primary-key
constraints. For foreign-key constraints, this column is the
ordinal position in key of the table that is being referenced.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
REFERENCED_TABLE_SCHEMA
</code>
</p>
<p>
The name of the schema referenced by the constraint.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
REFERENCED_TABLE_NAME
</code>
</p>
<p>
The name of the table referenced by the constraint.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
REFERENCED_COLUMN_NAME
</code>
</p>
<p>
The name of the column referenced by the constraint.
</p>
</li>
</ul>
</div>
<p>
Suppose that there are two tables name
<code class="literal">
t1
</code>
and
<code class="literal">
t3
</code>
that have the following definitions:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa60873672"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> t1
<span class="token punctuation">(</span>
s1 <span class="token datatype">INT</span><span class="token punctuation">,</span>
s2 <span class="token datatype">INT</span><span class="token punctuation">,</span>
s3 <span class="token datatype">INT</span><span class="token punctuation">,</span>
<span class="token keyword">PRIMARY</span> <span class="token keyword">KEY</span><span class="token punctuation">(</span>s3<span class="token punctuation">)</span>
<span class="token punctuation">)</span> <span class="token keyword">ENGINE</span><span class="token operator">=</span>InnoDB<span class="token punctuation">;</span>
<span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> t3
<span class="token punctuation">(</span>
s1 <span class="token datatype">INT</span><span class="token punctuation">,</span>
s2 <span class="token datatype">INT</span><span class="token punctuation">,</span>
s3 <span class="token datatype">INT</span><span class="token punctuation">,</span>
<span class="token keyword">KEY</span><span class="token punctuation">(</span>s1<span class="token punctuation">)</span><span class="token punctuation">,</span>
<span class="token keyword">CONSTRAINT</span> CO <span class="token keyword">FOREIGN</span> <span class="token keyword">KEY</span> <span class="token punctuation">(</span>s2<span class="token punctuation">)</span> <span class="token keyword">REFERENCES</span> t1<span class="token punctuation">(</span>s3<span class="token punctuation">)</span>
<span class="token punctuation">)</span> <span class="token keyword">ENGINE</span><span class="token operator">=</span>InnoDB<span class="token punctuation">;</span></code></pre>
</div>
<p>
For those two tables, the
<a class="link" href="information-schema-key-column-usage-table.html" title="28.3.16 The INFORMATION_SCHEMA KEY_COLUMN_USAGE Table">
<code class="literal">
KEY_COLUMN_USAGE
</code>
</a>
table has two rows:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
One row with
<code class="literal">
CONSTRAINT_NAME
</code>
=
<code class="literal">
'PRIMARY'
</code>
,
<code class="literal">
TABLE_NAME
</code>
=
<code class="literal">
't1'
</code>
,
<code class="literal">
COLUMN_NAME
</code>
=
<code class="literal">
's3'
</code>
,
<code class="literal">
ORDINAL_POSITION
</code>
=
<code class="literal">
1
</code>
,
<code class="literal">
POSITION_IN_UNIQUE_CONSTRAINT
</code>
=
<code class="literal">
NULL
</code>
.
</p>
<p>
For
<code class="literal">
NDB
</code>
: This value is always
<code class="literal">
NULL
</code>
.
</p>
</li>
<li class="listitem">
<p>
One row with
<code class="literal">
CONSTRAINT_NAME
</code>
=
<code class="literal">
'CO'
</code>
,
<code class="literal">
TABLE_NAME
</code>
=
<code class="literal">
't3'
</code>
,
<code class="literal">
COLUMN_NAME
</code>
=
<code class="literal">
's2'
</code>
,
<code class="literal">
ORDINAL_POSITION
</code>
=
<code class="literal">
1
</code>
,
<code class="literal">
POSITION_IN_UNIQUE_CONSTRAINT
</code>
=
<code class="literal">
1
</code>
.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/sys-sys-config-update-set-user.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="sys-sys-config-update-set-user">
</a>
30.4.2.3 The sys_config_update_set_user Trigger
</h4>
</div>
</div>
</div>
<p>
The
<a class="link" href="sys-sys-config-update-set-user.html" title="30.4.2.3 The sys_config_update_set_user Trigger">
<code class="literal">
sys_config_update_set_user
</code>
</a>
trigger for the
<a class="link" href="sys-sys-config.html" title="30.4.2.1 The sys_config Table">
<code class="literal">
sys_config
</code>
</a>
table
is similar to the
<a class="link" href="sys-sys-config-insert-set-user.html" title="30.4.2.2 The sys_config_insert_set_user Trigger">
<code class="literal">
sys_config_insert_set_user
</code>
</a>
trigger, but for
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
statements.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/windows-extract-archive.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="windows-extract-archive">
</a>
2.3.3.1 Extracting the Install Archive
</h4>
</div>
</div>
</div>
<p>
To install MySQL manually, do the following:
</p>
<div class="orderedlist">
<ol class="orderedlist" type="1">
<li class="listitem">
<p>
If you are upgrading from a previous version then refer to
<a class="xref" href="windows-upgrading.html" title="3.11 Upgrading MySQL on Windows">
Section 3.11, “Upgrading MySQL on Windows”
</a>
before beginning the
upgrade process.
</p>
</li>
<li class="listitem">
<p>
Make sure that you are logged in as a user with
administrator privileges.
</p>
</li>
<li class="listitem">
<p>
Choose an installation location. Traditionally, the MySQL
server is installed in
<code class="filename">
C:\mysql
</code>
. If you
do not install MySQL at
<code class="filename">
C:\mysql
</code>
, you
must specify the path to the install directory during
startup or in an option file. See
<a class="xref" href="windows-create-option-file.html" title="2.3.3.2 Creating an Option File">
Section 2.3.3.2, “Creating an Option File”
</a>
.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
The MSI installs MySQL under
<code class="filename">
C:\Program
Files\MySQL\MySQL Server 8.4
</code>
.
</p>
</div>
</li>
<li class="listitem">
<p>
Extract the install archive to the chosen installation
location using your preferred file-compression tool. Some
tools may extract the archive to a folder within your chosen
installation location. If this occurs, you can move the
contents of the subfolder into the chosen installation
location.
</p>
</li>
</ol>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/error-message-elements.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h2 class="title">
<a name="error-message-elements">
</a>
B.1 Error Message Sources and Elements
</h2>
</div>
</div>
</div>
<p>
This section discusses how error messages originate within MySQL
and the elements they contain.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="xref" href="error-message-elements.html#error-sources" title="Error Message Sources">
Error Message Sources
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="error-message-elements.html#error-elements" title="Error Message Elements">
Error Message Elements
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="error-message-elements.html#error-code-ranges" title="Error Code Ranges">
Error Code Ranges
</a>
</p>
</li>
</ul>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h3 class="title">
<a name="error-sources">
</a>
Error Message Sources
</h3>
</div>
</div>
</div>
<p>
Error messages can originate on the server side or the client
side:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
On the server side, error messages may occur during the
startup and shutdown processes, as a result of issues that
occur during SQL statement execution, and so forth.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
The MySQL server writes some error messages to its error
log. These indicate issues of interest to database
administrators or that require DBA action.
</p>
</li>
<li class="listitem">
<p>
The server sends other error messages to client
programs. These indicate issues pertaining only to a
particular client. The MySQL client library takes errors
received from the server and makes them available to the
host client program.
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
Client-side error messages are generated from within the
MySQL client library, usually involving problems
communicating with the server.
</p>
</li>
</ul>
</div>
<p>
Example server-side error messages written to the error log:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
This message produced during the startup process provides a
status or progress indicator:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-none"><div class="docs-select-all right" id="sa83206953"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-none">2018-10-28T13:01:32.735983Z 0 [Note] [MY-010303] [Server] Skipping
generation of SSL certificates as options related to SSL are specified.</code></pre>
</div>
</li>
<li class="listitem">
<p>
This message indicates an issue that requires DBA action:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-none"><div class="docs-select-all right" id="sa59934701"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-none">2018-10-02T03:20:39.410387Z 768 [ERROR] [MY-010045] [Server] Event Scheduler:
[evtuser@localhost][myschema.e_daily] Unknown database 'mydb'</code></pre>
</div>
</li>
</ul>
</div>
<p>
Example server-side error message sent to client programs, as
displayed by the
<a class="link" href="mysql.html" title="6.5.1 mysql — The MySQL Command-Line Client">
<span class="command">
<strong>
mysql
</strong>
</span>
</a>
client:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa90297123"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> no_such_table<span class="token punctuation">;</span>
<span class="token output">ERROR 1146 (42S02)<span class="token punctuation">:</span> Table 'test.no_such_table' doesn't exist</span></code></pre>
</div>
<p>
Example client-side error message originating from within the
client library, as displayed by the
<a class="link" href="mysql.html" title="6.5.1 mysql — The MySQL Command-Line Client">
<span class="command">
<strong>
mysql
</strong>
</span>
</a>
client:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-terminal"><div class="docs-select-all right" id="sa2382189"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token prompt">$> </span><span class="token command">mysql</span> <span class="token property">-h</span> no-such-host
<span class="token output">ERROR 2005 (HY000)<span class="token punctuation">:</span> Unknown MySQL server host 'no-such-host' (-2)</span></code></pre>
</div>
<p>
Whether an error originates from within the client library or is
received from the server, a MySQL client program may respond in
varying ways. As just illustrated, the client may display the
error message so the user can take corrective measures. The
client may instead internally attempt to resolve or retry a
failed operation, or take other action.
</p>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h3 class="title">
<a name="error-elements">
</a>
Error Message Elements
</h3>
</div>
</div>
</div>
<p>
When an error occurs, error information includes several
elements: an error code, SQLSTATE value, and message string.
These elements have the following characteristics:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Error code: This value is numeric. It is MySQL-specific and
is not portable to other database systems.
</p>
<p>
Each error number has a corresponding symbolic value.
Examples:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
The symbol for server error number
<code class="literal">
1146
</code>
is
<a class="ulink" href="/doc/mysql-errors/8.4/en/server-error-reference.html#error_er_no_such_table" target="_top">
<code class="literal">
ER_NO_SUCH_TABLE
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
The symbol for client error number
<code class="literal">
2005
</code>
is
<a class="ulink" href="/doc/mysql-errors/8.4/en/client-error-reference.html#error_cr_unknown_host" target="_top">
<code class="literal">
CR_UNKNOWN_HOST
</code>
</a>
.
</p>
</li>
</ul>
</div>
<p>
The set of error codes used in error messages is partitioned
into distinct ranges; see
<a class="xref" href="error-message-elements.html#error-code-ranges" title="Error Code Ranges">
Error Code Ranges
</a>
.
</p>
<p>
Error codes are stable across General Availability (GA)
releases of a given MySQL series. Before a series reaches GA
status, new codes may still be under development and are
subject to change.
</p>
</li>
<li class="listitem">
<p>
SQLSTATE value: This value is a five-character string (for
example,
<code class="literal">
'42S02'
</code>
). SQLSTATE values are
taken from ANSI SQL and ODBC and are more standardized than
the numeric error codes. The first two characters of an
SQLSTATE value indicate the error class:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
Class =
<code class="literal">
'00'
</code>
indicates success.
</p>
</li>
<li class="listitem">
<p>
Class =
<code class="literal">
'01'
</code>
indicates a warning.
</p>
</li>
<li class="listitem">
<p>
Class =
<code class="literal">
'02'
</code>
indicates
<span class="quote">
“
<span class="quote">
not
found.
</span>
”
</span>
This is relevant within the context of
cursors and is used to control what happens when a
cursor reaches the end of a data set. This condition
also occurs for
<code class="literal">
SELECT ... INTO
<em class="replaceable">
<code>
var_list
</code>
</em>
</code>
statements
that retrieve no rows.
</p>
</li>
<li class="listitem">
<p>
Class >
<code class="literal">
'02'
</code>
indicates an
exception.
</p>
</li>
</ul>
</div>
<p>
For server-side errors, not all MySQL error numbers have
corresponding SQLSTATE values. In these cases,
<code class="literal">
'HY000'
</code>
(general error) is used.
</p>
<p>
For client-side errors, the SQLSTATE value is always
<code class="literal">
'HY000'
</code>
(general error), so it is not
meaningful for distinguishing one client error from another.
</p>
</li>
<li class="listitem">
<p>
Message string: This string provides a textual description
of the error.
</p>
</li>
</ul>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h3 class="title">
<a name="error-code-ranges">
</a>
Error Code Ranges
</h3>
</div>
</div>
</div>
<p>
The set of error codes used in error messages is partitioned
into distinct ranges, each with its own purpose:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
1 to 999: Global error codes. This error code range is
called
<span class="quote">
“
<span class="quote">
global
</span>
”
</span>
because it is a shared range
that is used by the server as well as by clients.
</p>
<p>
When an error in this range originates on the server side,
the server writes it to the error log, padding the error
code with leading zeros to six digits and adding a prefix of
<code class="literal">
MY-
</code>
.
</p>
<p>
When an error in this range originates on the client side,
the client library makes it available to the client program
with no zero-padding or prefix.
</p>
</li>
<li class="listitem">
<p>
1,000 to 1,999: Server error codes reserved for messages
sent to clients.
</p>
</li>
<li class="listitem">
<p>
2,000 to 2,999: Client error codes reserved for use by the
client library.
</p>
</li>
<li class="listitem">
<p>
3,000 to 4,999: Server error codes reserved for messages
sent to clients.
</p>
</li>
<li class="listitem">
<p>
5,000 to 5,999: Error codes reserved for use by X Plugin
for messages sent to clients.
</p>
</li>
<li class="listitem">
<p>
10,000 to 49,999: Server error codes reserved for messages
to be written to the error log (not sent to clients).
</p>
<p>
When an error in this range occurs, the server writes it to
the error log, padding the error code with leading zeros to
six digits and adding a prefix of
<code class="literal">
MY-
</code>
.
</p>
</li>
<li class="listitem">
<p>
50,000 to 51,999: Error codes reserved for use by third
parties.
</p>
</li>
</ul>
</div>
<p>
The server handles error messages written to the error log
differently from error messages sent to clients:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
When the server writes a message to the error log, it pads
the error code with leading zeros to six digits and adds a
prefix of
<code class="literal">
MY-
</code>
(examples:
<a class="ulink" href="/doc/mysql-errors/8.4/en/global-error-reference.html#error_ee_unknown_charset" target="_top">
<code class="literal">
MY-000022
</code>
</a>
,
<a class="ulink" href="/doc/mysql-errors/8.4/en/server-error-reference.html#error_er_scheduler_stopped" target="_top">
<code class="literal">
MY-010048
</code>
</a>
).
</p>
</li>
<li class="listitem">
<p>
When the server sends a message to a client program, it adds
no zero-padding or prefix to the error code (examples:
<a class="ulink" href="/doc/mysql-errors/8.4/en/server-error-reference.html#error_er_open_as_readonly" target="_top">
<code class="literal">
1036
</code>
</a>
,
<a class="ulink" href="/doc/mysql-errors/8.4/en/server-error-reference.html#error_er_invalid_field_size" target="_top">
<code class="literal">
3013
</code>
</a>
).
</p>
</li>
</ul>
</div>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/create-table-gipks.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="create-table-gipks">
</a>
15.1.20.11 Generated Invisible Primary Keys
</h4>
</div>
</div>
</div>
<p>
MySQL 8.4 supports generated invisible primary keys
for any
<a class="link" href="innodb-storage-engine.html" title="Chapter 17 The InnoDB Storage Engine">
<code class="literal">
InnoDB
</code>
</a>
table that is
created without an explicit primary key. When the
<a class="link" href="server-system-variables.html#sysvar_sql_generate_invisible_primary_key">
<code class="literal">
sql_generate_invisible_primary_key
</code>
</a>
server system variable is set to
<code class="literal">
ON
</code>
, the
MySQL server automatically adds a generated invisible primary
key (GIPK) to any such table. This setting has no effect on
tables created using any other storage engine than
<code class="literal">
InnoDB
</code>
.
</p>
<p>
By default, the value of
<code class="literal">
sql_generate_invisible_primary_key
</code>
is
<code class="literal">
OFF
</code>
, meaning that the automatic addition of
GIPKs is disabled. To illustrate how this affects table
creation, we begin by creating two identical tables, neither
having a primary key, the only difference being that the first
(table
<code class="literal">
auto_0
</code>
) is created with
<code class="literal">
sql_generate_invisible_primary_key
</code>
set to
<code class="literal">
OFF
</code>
, and the second
(
<code class="literal">
auto_1
</code>
) after setting it to
<code class="literal">
ON
</code>
, as shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa41807155"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token variable">@@sql_generate_invisible_primary_key</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> @@sql_generate_invisible_primary_key <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 0 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output">1 row in set (0.00 sec)</span>
<span class="token prompt">mysql></span> <span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> auto_0 <span class="token punctuation">(</span>c1 <span class="token datatype">VARCHAR</span><span class="token punctuation">(</span><span class="token number">50</span><span class="token punctuation">)</span><span class="token punctuation">,</span> c2 <span class="token datatype">INT</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output">Query OK, 0 rows affected (0.02 sec)</span>
<span class="token prompt">mysql></span> <span class="token keyword">SET</span> sql_generate_invisible_primary_key<span class="token operator">=</span><span class="token keyword">ON</span><span class="token punctuation">;</span>
<span class="token output">Query OK, 0 rows affected (0.00 sec)</span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token variable">@@sql_generate_invisible_primary_key</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> @@sql_generate_invisible_primary_key <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output">1 row in set (0.00 sec)</span>
<span class="token prompt">mysql></span> <span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> auto_1 <span class="token punctuation">(</span>c1 <span class="token datatype">VARCHAR</span><span class="token punctuation">(</span><span class="token number">50</span><span class="token punctuation">)</span><span class="token punctuation">,</span> c2 <span class="token datatype">INT</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output">Query OK, 0 rows affected (0.04 sec)</span></code></pre>
</div>
<p>
Compare the output of these
<a class="link" href="show-create-table.html" title="15.7.7.11 SHOW CREATE TABLE Statement">
<code class="literal">
SHOW CREATE
TABLE
</code>
</a>
statements to see the difference in how the
tables were actually created:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa80711235"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SHOW</span> <span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> auto_0\G
<span class="token output"><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span> 1. row <span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span>
Table<span class="token punctuation">:</span> auto_0
Create Table<span class="token punctuation">:</span> CREATE TABLE `auto_0` (
`c1` varchar(50) DEFAULT NULL,
`c2` int DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
</span><span class="token output">1 row in set (0.00 sec)</span>
<span class="token prompt">mysql></span> <span class="token keyword">SHOW</span> <span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> auto_1\G
<span class="token output"><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span> 1. row <span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span>
Table<span class="token punctuation">:</span> auto_1
Create Table<span class="token punctuation">:</span> CREATE TABLE `auto_1` (
`my_row_id` bigint unsigned NOT NULL AUTO_INCREMENT /<span class="token punctuation">*</span>!80023 INVISIBLE <span class="token punctuation">*</span>/,
`c1` varchar(50) DEFAULT NULL,
`c2` int DEFAULT NULL,
PRIMARY KEY (`my_row_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
</span><span class="token output">1 row in set (0.00 sec)</span></code></pre>
</div>
<p>
Since
<code class="literal">
auto_1
</code>
had no primary key specified by
the
<code class="literal">
CREATE TABLE
</code>
statement used to create it,
setting
<code class="literal">
sql_generate_invisible_primary_key =
ON
</code>
causes MySQL to add both the invisible column
<code class="literal">
my_row_id
</code>
to this table and a primary key on
that column. Since
<code class="literal">
sql_generate_invisible_primary_key
</code>
was
<code class="literal">
OFF
</code>
at the time that
<code class="literal">
auto_0
</code>
was created, no such additions were
performed on that table.
</p>
<p>
When a primary key is added to a table by the server, the column
and key name is always
<code class="literal">
my_row_id
</code>
. For this
reason, when enabling generated invisible primary keys in this
way, you cannot create a table having a column named
<code class="literal">
my_row_id
</code>
unless the table creation statement
also specifies an explicit primary key. (You are not required to
name the column or key
<code class="literal">
my_row_id
</code>
in such
cases.)
</p>
<p>
<code class="literal">
my_row_id
</code>
is an invisible column, which means
it is not shown in the output of
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT *
</code>
</a>
or
<a class="link" href="table.html" title="15.2.16 TABLE Statement">
<code class="literal">
TABLE
</code>
</a>
; the column must be
selected explicitly by name. See
<a class="xref" href="invisible-columns.html" title="15.1.20.10 Invisible Columns">
Section 15.1.20.10, “Invisible Columns”
</a>
.
</p>
<p>
When GIPKs are enabled, a generated primary key cannot be
altered other than to switch it between
<code class="literal">
VISIBLE
</code>
and
<code class="literal">
INVISIBLE
</code>
. To
make the generated invisible primary key on
<code class="literal">
auto_1
</code>
visible, execute this
<a class="link" href="alter-table.html" title="15.1.9 ALTER TABLE Statement">
<code class="literal">
ALTER TABLE
</code>
</a>
statement:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa70040645"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">ALTER</span> <span class="token keyword">TABLE</span> auto_1 <span class="token keyword">ALTER</span> <span class="token keyword">COLUMN</span> my_row_id <span class="token keyword">SET</span> <span class="token keyword">VISIBLE</span><span class="token punctuation">;</span>
<span class="token output">Query OK, 0 rows affected (0.02 sec)</span>
<span class="token output">Records: 0 Duplicates: 0 Warnings: 0</span>
<span class="token prompt">mysql></span> <span class="token keyword">SHOW</span> <span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> auto_1\G
<span class="token output"><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span> 1. row <span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span>
Table<span class="token punctuation">:</span> auto_1
Create Table<span class="token punctuation">:</span> CREATE TABLE `auto_1` (
`my_row_id` bigint unsigned NOT NULL AUTO_INCREMENT,
`c1` varchar(50) DEFAULT NULL,
`c2` int DEFAULT NULL,
PRIMARY KEY (`my_row_id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
</span><span class="token output">1 row in set (0.01 sec)</span></code></pre>
</div>
<p>
To make this generated primary key invisible again, issue
<code class="literal">
ALTER TABLE auto_1 ALTER COLUMN my_row_id SET
INVISIBLE
</code>
.
</p>
<p>
A generated invisible primary key is always invisible by
default.
</p>
<p>
Whenever GIPKs are enabled, you cannot drop a generated primary
key if either of the following 2 conditions would result:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
The table is left with no primary key.
</p>
</li>
<li class="listitem">
<p>
The primary key is dropped, but not the primary key column.
</p>
</li>
</ul>
</div>
<p>
The effects of
<code class="literal">
sql_generate_invisible_primary_key
</code>
apply to
tables using the
<code class="literal">
InnoDB
</code>
storage engine only.
You can use an
<a class="link" href="alter-table.html" title="15.1.9 ALTER TABLE Statement">
<code class="literal">
ALTER TABLE
</code>
</a>
statement to change the storage engine used by a table that has
a generated invisible primary key; in this case, the primary key
and column remain in place, but the table and key no longer
receive any special treatment.
</p>
<p>
By default, GIPKs are shown in the output of
<a class="link" href="show-create-table.html" title="15.7.7.11 SHOW CREATE TABLE Statement">
<code class="literal">
SHOW CREATE TABLE
</code>
</a>
,
<a class="link" href="show-columns.html" title="15.7.7.6 SHOW COLUMNS Statement">
<code class="literal">
SHOW COLUMNS
</code>
</a>
, and
<a class="link" href="show-index.html" title="15.7.7.23 SHOW INDEX Statement">
<code class="literal">
SHOW INDEX
</code>
</a>
, and are visible in
the Information Schema
<a class="link" href="information-schema-columns-table.html" title="28.3.8 The INFORMATION_SCHEMA COLUMNS Table">
<code class="literal">
COLUMNS
</code>
</a>
and
<a class="link" href="information-schema-statistics-table.html" title="28.3.34 The INFORMATION_SCHEMA STATISTICS Table">
<code class="literal">
STATISTICS
</code>
</a>
tables. You can cause
generated invisible primary keys to be hidden instead in such
cases by setting the
<a class="link" href="server-system-variables.html#sysvar_show_gipk_in_create_table_and_information_schema">
<code class="literal">
show_gipk_in_create_table_and_information_schema
</code>
</a>
system variable to
<code class="literal">
OFF
</code>
. By default, this
variable is
<code class="literal">
ON
</code>
, as shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa24025038"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token variable">@@show_gipk_in_create_table_and_information_schema</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> @@show_gipk_in_create_table_and_information_schema <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output">1 row in set (0.00 sec)</span></code></pre>
</div>
<p>
As can be seen from the following query against the
<code class="literal">
COLUMNS
</code>
table,
<code class="literal">
my_row_id
</code>
is visible among the columns of
<code class="literal">
auto_1
</code>
:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa14707288"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token keyword">COLUMN_NAME</span><span class="token punctuation">,</span> ORDINAL_POSITION<span class="token punctuation">,</span> DATA_TYPE<span class="token punctuation">,</span> COLUMN_KEY
<span class="token prompt"> -></span> <span class="token keyword">FROM</span> INFORMATION_SCHEMA<span class="token punctuation">.</span><span class="token keyword">COLUMNS</span>
<span class="token prompt"> -></span> <span class="token keyword">WHERE</span> <span class="token keyword">TABLE_NAME</span> <span class="token operator">=</span> <span class="token string">"auto_1"</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> COLUMN_NAME <span class="token punctuation">|</span> ORDINAL_POSITION <span class="token punctuation">|</span> DATA_TYPE <span class="token punctuation">|</span> COLUMN_KEY <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> my_row_id <span class="token punctuation">|</span> 1 <span class="token punctuation">|</span> bigint <span class="token punctuation">|</span> PRI <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> c1 <span class="token punctuation">|</span> 2 <span class="token punctuation">|</span> varchar <span class="token punctuation">|</span> <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> c2 <span class="token punctuation">|</span> 3 <span class="token punctuation">|</span> int <span class="token punctuation">|</span> <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output">3 rows in set (0.01 sec)</span></code></pre>
</div>
<p>
After
<code class="literal">
show_gipk_in_create_table_and_information_schema
</code>
is set to
<code class="literal">
OFF
</code>
,
<code class="literal">
my_row_id
</code>
can no longer be seen in the
<code class="literal">
COLUMNS
</code>
table,
as shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa1165308"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SET</span> show_gipk_in_create_table_and_information_schema <span class="token operator">=</span> <span class="token keyword">OFF</span><span class="token punctuation">;</span>
<span class="token output">Query OK, 0 rows affected (0.00 sec)</span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token variable">@@show_gipk_in_create_table_and_information_schema</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> @@show_gipk_in_create_table_and_information_schema <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 0 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output">1 row in set (0.00 sec)</span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token keyword">COLUMN_NAME</span><span class="token punctuation">,</span> ORDINAL_POSITION<span class="token punctuation">,</span> DATA_TYPE<span class="token punctuation">,</span> COLUMN_KEY
<span class="token prompt"> -></span> <span class="token keyword">FROM</span> INFORMATION_SCHEMA<span class="token punctuation">.</span><span class="token keyword">COLUMNS</span>
<span class="token prompt"> -></span> <span class="token keyword">WHERE</span> <span class="token keyword">TABLE_NAME</span> <span class="token operator">=</span> <span class="token string">"auto_1"</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> COLUMN_NAME <span class="token punctuation">|</span> ORDINAL_POSITION <span class="token punctuation">|</span> DATA_TYPE <span class="token punctuation">|</span> COLUMN_KEY <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> c1 <span class="token punctuation">|</span> 2 <span class="token punctuation">|</span> varchar <span class="token punctuation">|</span> <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> c2 <span class="token punctuation">|</span> 3 <span class="token punctuation">|</span> int <span class="token punctuation">|</span> <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output">2 rows in set (0.00 sec)</span></code></pre>
</div>
<p>
The setting for
<code class="literal">
sql_generate_invisible_primary_key
</code>
is not
replicated, and is ignored by replication applier threads. This
means that the setting of this variable on the source has no
effect on the replica. You can cause the replica to add a GIPK
for tables replicated without primary keys on a given
replication channel using
<code class="literal">
REQUIRE_TABLE_PRIMARY_KEY_CHECK = GENERATE
</code>
as
part of a
<a class="link" href="change-replication-source-to.html" title="15.4.2.2 CHANGE REPLICATION SOURCE TO Statement">
<code class="literal">
CHANGE
REPLICATION SOURCE TO
</code>
</a>
statement.
</p>
<p>
GIPKs work with row-based replication of
<a class="link" href="create-table-select.html" title="15.1.20.4 CREATE TABLE ... SELECT Statement">
<code class="literal">
CREATE
TABLE ... SELECT
</code>
</a>
; the information written to the
binary log for this statement in such cases includes the GIPK
definition, and thus is replicated correctly. Statement-based
replication of
<code class="literal">
CREATE TABLE ... SELECT
</code>
is not
supported with
<code class="literal">
sql_generate_invisible_primary_key =
ON
</code>
.
</p>
<p>
When creating or importing backups of installations where GIPKs
are in use, it is possible to exclude generated invisible
primary key columns and values. The
<a class="link" href="mysqldump.html#option_mysqldump_skip-generated-invisible-primary-key">
<code class="option">
--skip-generated-invisible-primary-key
</code>
</a>
option for
<a class="link" href="mysqldump.html" title="6.5.4 mysqldump — A Database Backup Program">
<span class="command">
<strong>
mysqldump
</strong>
</span>
</a>
causes GIPK information
to be excluded in the program's output.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/information-schema-innodb-cached-indexes-table.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="information-schema-innodb-cached-indexes-table">
</a>
28.4.5 The INFORMATION_SCHEMA INNODB_CACHED_INDEXES Table
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045077331680">
</a>
<p>
The
<a class="link" href="information-schema-innodb-cached-indexes-table.html" title="28.4.5 The INFORMATION_SCHEMA INNODB_CACHED_INDEXES Table">
<code class="literal">
INNODB_CACHED_INDEXES
</code>
</a>
table
reports the number of index pages cached in the
<code class="literal">
InnoDB
</code>
buffer pool for each index.
</p>
<p>
For related usage information and examples, see
<a class="xref" href="innodb-information-schema-buffer-pool-tables.html" title="17.15.5 InnoDB INFORMATION_SCHEMA Buffer Pool Tables">
Section 17.15.5, “InnoDB INFORMATION_SCHEMA Buffer Pool Tables”
</a>
.
</p>
<p>
The
<a class="link" href="information-schema-innodb-cached-indexes-table.html" title="28.4.5 The INFORMATION_SCHEMA INNODB_CACHED_INDEXES Table">
<code class="literal">
INNODB_CACHED_INDEXES
</code>
</a>
table has
these columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
SPACE_ID
</code>
</p>
<p>
The tablespace ID.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
INDEX_ID
</code>
</p>
<p>
An identifier for the index. Index identifiers are unique
across all the databases in an instance.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
N_CACHED_PAGES
</code>
</p>
<p>
The total number of index pages cached in the
<code class="literal">
InnoDB
</code>
buffer pool for a specific index
since MySQL Server last started.
</p>
</li>
</ul>
</div>
<h4>
<a name="idm46045077317728">
</a>
Examples
</h4>
<p>
This query returns the number of index pages cached in the
<code class="literal">
InnoDB
</code>
buffer pool for a specific index:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa68442684"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> INFORMATION_SCHEMA<span class="token punctuation">.</span>INNODB_CACHED_INDEXES <span class="token keyword">WHERE</span> INDEX_ID<span class="token operator">=</span><span class="token number">65</span>\G
<span class="token output"><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span> 1. row <span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span>
SPACE_ID<span class="token punctuation">:</span> 4294967294
INDEX_ID<span class="token punctuation">:</span> 65
N_CACHED_PAGES<span class="token punctuation">:</span> 45</span></code></pre>
</div>
<p>
This query returns the number of index pages cached in the
<code class="literal">
InnoDB
</code>
buffer pool for each index, using the
<a class="link" href="information-schema-innodb-indexes-table.html" title="28.4.20 The INFORMATION_SCHEMA INNODB_INDEXES Table">
<code class="literal">
INNODB_INDEXES
</code>
</a>
and
<a class="link" href="information-schema-innodb-tables-table.html" title="28.4.23 The INFORMATION_SCHEMA INNODB_TABLES Table">
<code class="literal">
INNODB_TABLES
</code>
</a>
tables to resolve the
table name and index name for each
<code class="literal">
INDEX_ID
</code>
value.
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa6187851"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span>
<span class="token keyword">tables</span><span class="token punctuation">.</span><span class="token keyword">NAME</span> <span class="token keyword">AS</span> <span class="token keyword">table_name</span><span class="token punctuation">,</span>
<span class="token keyword">indexes</span><span class="token punctuation">.</span><span class="token keyword">NAME</span> <span class="token keyword">AS</span> index_name<span class="token punctuation">,</span>
cached<span class="token punctuation">.</span>N_CACHED_PAGES <span class="token keyword">AS</span> n_cached_pages
<span class="token keyword">FROM</span>
INFORMATION_SCHEMA<span class="token punctuation">.</span>INNODB_CACHED_INDEXES <span class="token keyword">AS</span> cached<span class="token punctuation">,</span>
INFORMATION_SCHEMA<span class="token punctuation">.</span>INNODB_INDEXES <span class="token keyword">AS</span> <span class="token keyword">indexes</span><span class="token punctuation">,</span>
INFORMATION_SCHEMA<span class="token punctuation">.</span>INNODB_TABLES <span class="token keyword">AS</span> <span class="token keyword">tables</span>
<span class="token keyword">WHERE</span>
cached<span class="token punctuation">.</span>INDEX_ID <span class="token operator">=</span> <span class="token keyword">indexes</span><span class="token punctuation">.</span>INDEX_ID
<span class="token operator">AND</span> <span class="token keyword">indexes</span><span class="token punctuation">.</span>TABLE_ID <span class="token operator">=</span> <span class="token keyword">tables</span><span class="token punctuation">.</span>TABLE_ID<span class="token punctuation">;</span></code></pre>
</div>
<h4>
<a name="idm46045077308224">
</a>
Notes
</h4>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
You must have the
<a class="link" href="privileges-provided.html#priv_process">
<code class="literal">
PROCESS
</code>
</a>
privilege to query this table.
</p>
</li>
<li class="listitem">
<p>
Use the
<code class="literal">
INFORMATION_SCHEMA
</code>
<a class="link" href="information-schema-columns-table.html" title="28.3.8 The INFORMATION_SCHEMA COLUMNS Table">
<code class="literal">
COLUMNS
</code>
</a>
table or the
<a class="link" href="show-columns.html" title="15.7.7.6 SHOW COLUMNS Statement">
<code class="literal">
SHOW COLUMNS
</code>
</a>
statement to view
additional information about the columns of this table,
including data types and default values.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/window-functions.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h2 class="title">
<a name="window-functions">
</a>
14.20 Window Functions
</h2>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="window-function-descriptions.html">
14.20.1 Window Function Descriptions
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="window-functions-usage.html">
14.20.2 Window Function Concepts and Syntax
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="window-functions-frames.html">
14.20.3 Window Function Frame Specification
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="window-functions-named-windows.html">
14.20.4 Named Windows
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="window-function-restrictions.html">
14.20.5 Window Function Restrictions
</a>
</span>
</dt>
</dl>
</div>
<a class="indexterm" name="idm46045192357248">
</a>
<p>
MySQL supports window functions that, for each row from a query,
perform a calculation using rows related to that row. The
following sections discuss how to use window functions, including
descriptions of the
<code class="literal">
OVER
</code>
and
<code class="literal">
WINDOW
</code>
clauses. The first section provides
descriptions of the nonaggregate window functions. For
descriptions of the aggregate window functions, see
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
.
</p>
<p>
For information about optimization and window functions, see
<a class="xref" href="window-function-optimization.html" title="10.2.1.21 Window Function Optimization">
Section 10.2.1.21, “Window Function Optimization”
</a>
.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/spatial-reference-systems.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="spatial-reference-systems">
</a>
13.4.5 Spatial Reference System Support
</h3>
</div>
</div>
</div>
<p>
A spatial reference system (SRS) for spatial data is a
coordinate-based system for geographic locations.
</p>
<p>
There are different types of spatial reference systems:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
A projected SRS is a projection of a globe onto a flat
surface; that is, a flat map. For example, a light bulb
inside a globe that shines on a paper cylinder surrounding
the globe projects a map onto the paper. The result is
georeferenced: Each point maps to a place on the globe. The
coordinate system on that plane is Cartesian using a length
unit (meters, feet, and so forth), rather than degrees of
longitude and latitude.
</p>
<p>
The globes in this case are ellipsoids; that is, flattened
spheres. Earth is a bit shorter in its North-South axis than
its East-West axis, so a slightly flattened sphere is more
correct, but perfect spheres permit faster calculations.
</p>
</li>
<li class="listitem">
<p>
A geographic SRS is a nonprojected SRS representing
longitude-latitude (or latitude-longitude) coordinates on an
ellipsoid, in any angular unit.
</p>
</li>
<li class="listitem">
<p>
The SRS denoted in MySQL by SRID 0 represents an infinite
flat Cartesian plane with no units assigned to its axes.
Unlike projected SRSs, it is not georeferenced and it does
not necessarily represent Earth. It is an abstract plane
that can be used for anything. SRID 0 is the default SRID
for spatial data in MySQL.
</p>
</li>
</ul>
</div>
<p>
MySQL maintains information about available spatial reference
systems for spatial data in the data dictionary
<code class="literal">
mysql.st_spatial_reference_systems
</code>
table,
which can store entries for projected and geographic SRSs. This
data dictionary table is invisible, but SRS entry contents are
available through the
<code class="literal">
INFORMATION_SCHEMA
</code>
<a class="link" href="information-schema-st-spatial-reference-systems-table.html" title="28.3.36 The INFORMATION_SCHEMA ST_SPATIAL_REFERENCE_SYSTEMS Table">
<code class="literal">
ST_SPATIAL_REFERENCE_SYSTEMS
</code>
</a>
table,
implemented as a view on
<code class="literal">
mysql.st_spatial_reference_systems
</code>
(see
<a class="xref" href="information-schema-st-spatial-reference-systems-table.html" title="28.3.36 The INFORMATION_SCHEMA ST_SPATIAL_REFERENCE_SYSTEMS Table">
Section 28.3.36, “The INFORMATION_SCHEMA ST_SPATIAL_REFERENCE_SYSTEMS Table”
</a>
).
</p>
<p>
The following example shows what an SRS entry looks like:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa37136740"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token operator">*</span>
<span class="token keyword">FROM</span> INFORMATION_SCHEMA<span class="token punctuation">.</span>ST_SPATIAL_REFERENCE_SYSTEMS
<span class="token keyword">WHERE</span> SRS_ID <span class="token operator">=</span> <span class="token number">4326</span>\G
<span class="token output"><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span> 1. row <span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span>
SRS_NAME<span class="token punctuation">:</span> WGS 84
SRS_ID<span class="token punctuation">:</span> 4326
ORGANIZATION<span class="token punctuation">:</span> EPSG
ORGANIZATION_COORDSYS_ID<span class="token punctuation">:</span> 4326
DEFINITION<span class="token punctuation">:</span> GEOGCS["WGS 84",DATUM["World Geodetic System 1984",
SPHEROID["WGS 84",6378137,298.257223563,
AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],
PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],
UNIT["degree",0.017453292519943278,
AUTHORITY["EPSG","9122"]],
AXIS["Lat",NORTH],AXIS["Long",EAST],
AUTHORITY["EPSG","4326"]]
DESCRIPTION<span class="token punctuation">:</span></span></code></pre>
</div>
<p>
This entry describes the SRS used for GPS systems. It has the
name (
<code class="literal">
SRS_NAME
</code>
) WGS 84 and the ID
(
<code class="literal">
SRS_ID
</code>
) 4326, which is the ID used by the
<a class="ulink" href="http://epsg.org" target="_blank">
European Petroleum Survey
Group
</a>
(EPSG).
</p>
<p>
SRS definitions in the
<code class="literal">
DEFINITION
</code>
column are
WKT values, represented as specified in the
<a class="ulink" href="http://www.opengeospatial.org" target="_blank">
Open Geospatial
Consortium
</a>
document
<a class="ulink" href="http://docs.opengeospatial.org/is/12-063r5/12-063r5.html" target="_blank">
OGC
12-063r5
</a>
.
</p>
<p>
<code class="literal">
SRS_ID
</code>
values represent the same kind of
values as the SRID of geometry values or passed as the SRID
argument to spatial functions. SRID 0 (the unitless Cartesian
plane) is special. It is always a legal spatial reference system
ID and can be used in any computations on spatial data that
depend on SRID values.
</p>
<p>
For computations on multiple geometry values, all values must
have the same SRID or an error occurs.
</p>
<p>
SRS definition parsing occurs on demand when definitions are
needed by GIS functions. Parsed definitions are stored in the
data dictionary cache to enable reuse and avoid incurring
parsing overhead for every statement that needs SRS information.
</p>
<p>
To enable manipulation of SRS entries stored in the data
dictionary, MySQL provides these SQL statements:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="link" href="create-spatial-reference-system.html" title="15.1.19 CREATE SPATIAL REFERENCE SYSTEM Statement">
<code class="literal">
CREATE SPATIAL REFERENCE
SYSTEM
</code>
</a>
: See
<a class="xref" href="create-spatial-reference-system.html" title="15.1.19 CREATE SPATIAL REFERENCE SYSTEM Statement">
Section 15.1.19, “CREATE SPATIAL REFERENCE SYSTEM Statement”
</a>
. The
description for this statement includes additional
information about SRS components.
</p>
</li>
<li class="listitem">
<p>
<a class="link" href="drop-spatial-reference-system.html" title="15.1.31 DROP SPATIAL REFERENCE SYSTEM Statement">
<code class="literal">
DROP SPATIAL REFERENCE
SYSTEM
</code>
</a>
: See
<a class="xref" href="drop-spatial-reference-system.html" title="15.1.31 DROP SPATIAL REFERENCE SYSTEM Statement">
Section 15.1.31, “DROP SPATIAL REFERENCE SYSTEM Statement”
</a>
.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/execute.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="execute">
</a>
15.5.2 EXECUTE Statement
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045176553376">
</a>
<a class="indexterm" name="idm46045176552304">
</a>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa65962340"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">EXECUTE</span> <em class="replaceable">stmt_name</em>
<span class="token punctuation">[</span><span class="token keyword">USING</span> <span class="token variable">@<em class="replaceable">var_name</em></span> <span class="token punctuation">[</span><span class="token punctuation">,</span> <span class="token variable">@<em class="replaceable">var_name</em></span><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">]</span></code></pre>
</div>
<p>
After preparing a statement with
<a class="link" href="prepare.html" title="15.5.1 PREPARE Statement">
<code class="literal">
PREPARE
</code>
</a>
, you execute it with an
<a class="link" href="execute.html" title="15.5.2 EXECUTE Statement">
<code class="literal">
EXECUTE
</code>
</a>
statement that refers to
the prepared statement name. If the prepared statement contains
any parameter markers, you must supply a
<code class="literal">
USING
</code>
clause that lists user variables containing the values to be bound
to the parameters. Parameter values can be supplied only by user
variables, and the
<code class="literal">
USING
</code>
clause must name
exactly as many variables as the number of parameter markers in
the statement.
</p>
<p>
You can execute a given prepared statement multiple times, passing
different variables to it or setting the variables to different
values before each execution.
</p>
<p>
For examples, see
<a class="xref" href="sql-prepared-statements.html" title="15.5 Prepared Statements">
Section 15.5, “Prepared Statements”
</a>
.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/server-option-variable-reference.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="server-option-variable-reference">
</a>
7.1.4 Server Option, System Variable, and Status Variable Reference
</h3>
</div>
</div>
</div>
<p>
The following table lists all command-line options, system
variables, and status variables applicable within
<code class="literal">
mysqld
</code>
.
</p>
<p>
The table lists command-line options (Cmd-line), options valid in
configuration files (Option file), server system variables (System
Var), and status variables (Status var) in one unified list, with
an indication of where each option or variable is valid. If a
server option set on the command line or in an option file differs
from the name of the corresponding system variable, the variable
name is noted immediately below the corresponding option. For
system and status variables, the scope of the variable (Var Scope)
is Global, Session, or both. Please see the corresponding item
descriptions for details on setting and using the options and
variables. Where appropriate, direct links to further information
about the items are provided.
</p>
<p>
For a version of this table that is specific to NDB Cluster, see
<a class="xref" href="mysql-cluster-option-tables.html" title="25.4.2.5 NDB Cluster mysqld Option and Variable Reference">
Section 25.4.2.5, “NDB Cluster mysqld Option and Variable Reference”
</a>
.
</p>
<div class="table">
<a name="idm46045302377616">
</a>
<p class="title">
<b>
Table 7.1 Command-Line Option, System Variable, and Status
Variable Summary
</b>
</p>
<div class="table-contents">
<table frame="box" rules="all" summary="Reference for mysqld command-line options, system variables, and status variables.">
<colgroup>
<col style="width: 20%"/>
<col style="width: 15%"/>
<col style="width: 15%"/>
<col style="width: 15%"/>
<col style="width: 15%"/>
<col style="width: 15%"/>
<col style="width: 15%"/>
</colgroup>
<thead>
<tr>
<th scope="col">
Name
</th>
<th scope="col">
Cmd-Line
</th>
<th scope="col">
Option File
</th>
<th scope="col">
System Var
</th>
<th scope="col">
Status Var
</th>
<th scope="col">
Var Scope
</th>
<th scope="col">
Dynamic
</th>
</tr>
</thead>
<tbody>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Aborted_clients">
Aborted_clients
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Aborted_connects">
Aborted_connects
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Acl_cache_items_count">
Acl_cache_items_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_activate_all_roles_on_login">
activate_all_roles_on_login
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_admin_address">
admin_address
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_admin_port">
admin_port
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_admin_ssl_ca">
admin_ssl_ca
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_admin_ssl_capath">
admin_ssl_capath
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_admin_ssl_cert">
admin_ssl_cert
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_admin_ssl_cipher">
admin_ssl_cipher
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_admin_ssl_crl">
admin_ssl_crl
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_admin_ssl_crlpath">
admin_ssl_crlpath
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_admin_ssl_key">
admin_ssl_key
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_admin_tls_ciphersuites">
admin_tls_ciphersuites
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_admin_tls_version">
admin_tls_version
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_allow-suspicious-udfs">
allow-suspicious-udfs
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_ansi">
ansi
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#option_mysqld_audit-log">
audit-log
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_buffer_size">
audit_log_buffer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_compression">
audit_log_compression
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_connection_policy">
audit_log_connection_policy
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_current_session">
audit_log_current_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#statvar_Audit_log_current_size">
Audit_log_current_size
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_database">
audit_log_database
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#statvar_Audit_log_direct_writes">
Audit_log_direct_writes
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_disable">
audit_log_disable
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_encryption">
audit_log_encryption
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#statvar_Audit_log_event_max_drop_size">
Audit_log_event_max_drop_size
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#statvar_Audit_log_events">
Audit_log_events
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#statvar_Audit_log_events_filtered">
Audit_log_events_filtered
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#statvar_Audit_log_events_lost">
Audit_log_events_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#statvar_Audit_log_events_written">
Audit_log_events_written
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_exclude_accounts">
audit_log_exclude_accounts
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_file">
audit_log_file
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_filter_id">
audit_log_filter_id
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_flush">
audit_log_flush
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_flush_interval_seconds">
audit_log_flush_interval_seconds
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_format">
audit_log_format
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_format_unix_timestamp">
audit_log_format_unix_timestamp
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_include_accounts">
audit_log_include_accounts
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_max_size">
audit_log_max_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_password_history_keep_days">
audit_log_password_history_keep_days
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_policy">
audit_log_policy
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_prune_seconds">
audit_log_prune_seconds
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_read_buffer_size">
audit_log_read_buffer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_rotate_on_size">
audit_log_rotate_on_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_statement_policy">
audit_log_statement_policy
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#sysvar_audit_log_strategy">
audit_log_strategy
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#statvar_Audit_log_total_size">
Audit_log_total_size
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="audit-log-reference.html#statvar_Audit_log_write_waits">
Audit_log_write_waits
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_kerberos_service_key_tab">
authentication_kerberos_service_key_tab
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_kerberos_service_principal">
authentication_kerberos_service_principal
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_auth_method_name">
authentication_ldap_sasl_auth_method_name
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_bind_base_dn">
authentication_ldap_sasl_bind_base_dn
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_bind_root_dn">
authentication_ldap_sasl_bind_root_dn
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_bind_root_pwd">
authentication_ldap_sasl_bind_root_pwd
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_ca_path">
authentication_ldap_sasl_ca_path
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_connect_timeout">
authentication_ldap_sasl_connect_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_group_search_attr">
authentication_ldap_sasl_group_search_attr
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_group_search_filter">
authentication_ldap_sasl_group_search_filter
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_init_pool_size">
authentication_ldap_sasl_init_pool_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_log_status">
authentication_ldap_sasl_log_status
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_max_pool_size">
authentication_ldap_sasl_max_pool_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_referral">
authentication_ldap_sasl_referral
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_response_timeout">
authentication_ldap_sasl_response_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_server_host">
authentication_ldap_sasl_server_host
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_server_port">
authentication_ldap_sasl_server_port
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Authentication_ldap_sasl_supported_methods">
Authentication_ldap_sasl_supported_methods
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_tls">
authentication_ldap_sasl_tls
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_sasl_user_search_attr">
authentication_ldap_sasl_user_search_attr
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_auth_method_name">
authentication_ldap_simple_auth_method_name
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_bind_base_dn">
authentication_ldap_simple_bind_base_dn
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_bind_root_dn">
authentication_ldap_simple_bind_root_dn
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_bind_root_pwd">
authentication_ldap_simple_bind_root_pwd
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_ca_path">
authentication_ldap_simple_ca_path
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_connect_timeout">
authentication_ldap_simple_connect_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_group_search_attr">
authentication_ldap_simple_group_search_attr
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_group_search_filter">
authentication_ldap_simple_group_search_filter
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_init_pool_size">
authentication_ldap_simple_init_pool_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_log_status">
authentication_ldap_simple_log_status
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_max_pool_size">
authentication_ldap_simple_max_pool_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_referral">
authentication_ldap_simple_referral
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_response_timeout">
authentication_ldap_simple_response_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_server_host">
authentication_ldap_simple_server_host
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_server_port">
authentication_ldap_simple_server_port
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_tls">
authentication_ldap_simple_tls
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_ldap_simple_user_search_attr">
authentication_ldap_simple_user_search_attr
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_authentication_policy">
authentication_policy
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="pluggable-authentication-system-variables.html#sysvar_authentication_webauthn_rp_id">
authentication_webauthn_rp_id
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_authentication_windows_log_level">
authentication_windows_log_level
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_authentication_windows_use_principal_name">
authentication_windows_use_principal_name
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_auto_generate_certs">
auto_generate_certs
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#sysvar_auto_increment_increment">
auto_increment_increment
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#sysvar_auto_increment_offset">
auto_increment_offset
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_autocommit">
autocommit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_automatic_sp_privileges">
automatic_sp_privileges
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_back_log">
back_log
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_basedir">
basedir
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_big_tables">
big_tables
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_bind_address">
bind_address
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Binlog_cache_disk_use">
Binlog_cache_disk_use
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_cache_size">
binlog_cache_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Binlog_cache_use">
Binlog_cache_use
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#option_mysqld_binlog-checksum">
binlog-checksum
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_checksum">
binlog_checksum
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_direct_non_transactional_updates">
binlog_direct_non_transactional_updates
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#option_mysqld_binlog-do-db">
binlog-do-db
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_encryption">
binlog_encryption
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_error_action">
binlog_error_action
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_expire_logs_auto_purge">
binlog_expire_logs_auto_purge
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_expire_logs_seconds">
binlog_expire_logs_seconds
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_format">
binlog_format
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_group_commit_sync_delay">
binlog_group_commit_sync_delay
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_group_commit_sync_no_delay_count">
binlog_group_commit_sync_no_delay_count
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-gtids.html#sysvar_binlog_gtid_simple_recovery">
binlog_gtid_simple_recovery
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#option_mysqld_binlog-ignore-db">
binlog-ignore-db
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_max_flush_queue_time">
binlog_max_flush_queue_time
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_order_commits">
binlog_order_commits
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_rotate_encryption_master_key_at_startup">
binlog_rotate_encryption_master_key_at_startup
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#option_mysqld_binlog-row-event-max-size">
binlog_row_event_max_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_row_image">
binlog_row_image
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_row_metadata">
binlog_row_metadata
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_row_value_options">
binlog_row_value_options
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_rows_query_log_events">
binlog_rows_query_log_events
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Binlog_stmt_cache_disk_use">
Binlog_stmt_cache_disk_use
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_stmt_cache_size">
binlog_stmt_cache_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Binlog_stmt_cache_use">
Binlog_stmt_cache_use
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_transaction_compression">
binlog_transaction_compression
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_transaction_compression_level_zstd">
binlog_transaction_compression_level_zstd
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_transaction_dependency_history_size">
binlog_transaction_dependency_history_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_block_encryption_mode">
block_encryption_mode
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_build_id">
build_id
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_bulk_insert_buffer_size">
bulk_insert_buffer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Bytes_received">
Bytes_received
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Bytes_sent">
Bytes_sent
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_caching_sha2_password_auto_generate_rsa_keys">
caching_sha2_password_auto_generate_rsa_keys
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_caching_sha2_password_digest_rounds">
caching_sha2_password_digest_rounds
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_caching_sha2_password_private_key_path">
caching_sha2_password_private_key_path
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_caching_sha2_password_public_key_path">
caching_sha2_password_public_key_path
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Caching_sha2_password_rsa_public_key">
Caching_sha2_password_rsa_public_key
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_character_set_client">
character_set_client
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_character_set_connection">
character_set_connection
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_character_set_database">
character_set_database
</a>
(note 1)
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_character_set_filesystem">
character_set_filesystem
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_character_set_results">
character_set_results
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_character_set_server">
character_set_server
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_character_set_system">
character_set_system
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_character_sets_dir">
character_sets_dir
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_check_proxy_users">
check_proxy_users
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_chroot">
chroot
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="clone-plugin-options-variables.html#sysvar_clone_autotune_concurrency">
clone_autotune_concurrency
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="clone-plugin-options-variables.html#sysvar_clone_block_ddl">
clone_block_ddl
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="clone-plugin-options-variables.html#sysvar_clone_buffer_size">
clone_buffer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="clone-plugin-options-variables.html#sysvar_clone_ddl_timeout">
clone_ddl_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="clone-plugin-options-variables.html#sysvar_clone_delay_after_data_drop">
clone_delay_after_data_drop
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="clone-plugin-options-variables.html#sysvar_clone_donor_timeout_after_network_failure">
clone_donor_timeout_after_network_failure
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="clone-plugin-options-variables.html#sysvar_clone_enable_compression">
clone_enable_compression
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="clone-plugin-options-variables.html#sysvar_clone_max_concurrency">
clone_max_concurrency
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="clone-plugin-options-variables.html#sysvar_clone_max_data_bandwidth">
clone_max_data_bandwidth
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="clone-plugin-options-variables.html#sysvar_clone_max_network_bandwidth">
clone_max_network_bandwidth
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="clone-plugin-options-variables.html#sysvar_clone_ssl_ca">
clone_ssl_ca
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="clone-plugin-options-variables.html#sysvar_clone_ssl_cert">
clone_ssl_cert
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="clone-plugin-options-variables.html#sysvar_clone_ssl_key">
clone_ssl_key
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="clone-plugin-options-variables.html#sysvar_clone_valid_donor_list">
clone_valid_donor_list
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_collation_connection">
collation_connection
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_collation_database">
collation_database
</a>
(note 1)
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_collation_server">
collation_server
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_admin_commands
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_alter_db
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_alter_event
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_alter_function
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_alter_procedure
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_alter_resource_group
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_alter_server
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_alter_table
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_alter_tablespace
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_alter_user
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_alter_user_default_role
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_analyze
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_assign_to_keycache
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_begin
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_binlog
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_call_procedure
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_change_db
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_change_repl_filter
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_change_replication_source
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_check
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_checksum
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_clone
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_commit
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_create_db
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_create_event
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_create_function
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_create_index
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_create_procedure
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_create_resource_group
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_create_role
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_create_server
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_create_table
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_create_trigger
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_create_udf
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_create_user
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_create_view
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_dealloc_sql
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_delete
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_delete_multi
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_do
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_drop_db
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_drop_event
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_drop_function
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_drop_index
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_drop_procedure
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_drop_resource_group
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_drop_role
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_drop_server
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_drop_table
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_drop_trigger
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_drop_user
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_drop_view
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_empty_query
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_execute_sql
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_explain_other
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_flush
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_get_diagnostics
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_grant
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_grant_roles
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_group_replication_start
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_group_replication_stop
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_ha_close
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_ha_open
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_ha_read
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_help
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_insert
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_insert_select
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_install_component
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_install_plugin
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_kill
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_load
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_lock_tables
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_optimize
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_preload_keys
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_prepare_sql
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_purge
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_purge_before_date
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_release_savepoint
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_rename_table
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_rename_user
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_repair
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_replace
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_replace_select
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_replica_start
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_replica_stop
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_reset
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_resignal
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_restart
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_revoke
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_revoke_all
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_revoke_roles
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_rollback
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_rollback_to_savepoint
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_savepoint
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_select
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_set_option
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_set_resource_group
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_set_role
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_authors
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_binary_log_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_binlog_events
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_binlogs
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_charsets
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_collations
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_contributors
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_create_db
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_create_event
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_create_func
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_create_proc
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_create_table
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_create_trigger
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_create_user
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_databases
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_engine_logs
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_engine_mutex
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_engine_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_errors
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_events
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_fields
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_function_code
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_function_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_grants
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_keys
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_ndb_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_open_tables
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_plugins
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_privileges
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_procedure_code
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_procedure_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_processlist
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_profile
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_profiles
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_relaylog_events
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_replica_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_replicas
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_storage_engines
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_table_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_tables
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_triggers
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_variables
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_show_warnings
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_shutdown
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_signal
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_stmt_close
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_stmt_execute
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_stmt_fetch
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_stmt_prepare
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_stmt_reprepare
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_stmt_reset
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_stmt_send_long_data
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_truncate
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_uninstall_component
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_uninstall_plugin
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_unlock_tables
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_update
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_update_multi
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_xa_commit
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_xa_end
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_xa_prepare
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_xa_recover
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_xa_rollback
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Com_xxx">
Com_xa_start
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_completion_type">
completion_type
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="data-masking-component-variables.html#sysvar_component_masking.dictionaries_flush_interval_seconds">
component_masking.dictionaries_flush_interval_seconds
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="data-masking-component-variables.html#sysvar_component_masking.masking_database">
component_masking.masking_database
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_component_scheduler.enabled">
component_scheduler.enabled
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Compression">
Compression
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Compression_algorithm">
Compression_algorithm
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Compression_level">
Compression_level
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_concurrent_insert">
concurrent_insert
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_connect_timeout">
connect_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="connection-control-variables.html#statvar_Connection_control_delay_generated">
Connection_control_delay_generated
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="connection-control-variables.html#sysvar_connection_control_failed_connections_threshold">
connection_control_failed_connections_threshold
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="connection-control-variables.html#sysvar_connection_control_max_connection_delay">
connection_control_max_connection_delay
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="connection-control-variables.html#sysvar_connection_control_min_connection_delay">
connection_control_min_connection_delay
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Connection_errors_accept">
Connection_errors_accept
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Connection_errors_internal">
Connection_errors_internal
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Connection_errors_max_connections">
Connection_errors_max_connections
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Connection_errors_peer_address">
Connection_errors_peer_address
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Connection_errors_select">
Connection_errors_select
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Connection_errors_tcpwrap">
Connection_errors_tcpwrap
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_connection_memory_chunk_size">
connection_memory_chunk_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_connection_memory_limit">
connection_memory_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Connections">
Connections
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_console">
console
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_core-file">
core-file
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_core_file">
core_file
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_create_admin_listener_thread">
create_admin_listener_thread
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Created_tmp_disk_tables">
Created_tmp_disk_tables
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Created_tmp_files">
Created_tmp_files
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Created_tmp_tables">
Created_tmp_tables
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_cte_max_recursion_depth">
cte_max_recursion_depth
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Current_tls_ca">
Current_tls_ca
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Current_tls_capath">
Current_tls_capath
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Current_tls_cert">
Current_tls_cert
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Current_tls_cipher">
Current_tls_cipher
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Current_tls_ciphersuites">
Current_tls_ciphersuites
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Current_tls_crl">
Current_tls_crl
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Current_tls_crlpath">
Current_tls_crlpath
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Current_tls_key">
Current_tls_key
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Current_tls_version">
Current_tls_version
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_daemonize">
daemonize
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_datadir">
datadir
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="ddl-rewriter-options.html#option_mysqld_ddl-rewriter">
ddl-rewriter
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_debug">
debug
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_debug_sync">
debug_sync
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_debug-sync-timeout">
debug-sync-timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_default_collation_for_utf8mb4">
default_collation_for_utf8mb4
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_default_password_lifetime">
default_password_lifetime
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_default_storage_engine">
default_storage_engine
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_default_table_encryption">
default_table_encryption
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_default-time-zone">
default-time-zone
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_default_tmp_storage_engine">
default_tmp_storage_engine
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_default_week_format">
default_week_format
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_defaults-extra-file">
defaults-extra-file
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_defaults-file">
defaults-file
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_defaults-group-suffix">
defaults-group-suffix
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_delay_key_write">
delay_key_write
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Delayed_errors">
Delayed_errors
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_delayed_insert_limit">
delayed_insert_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Delayed_insert_threads">
Delayed_insert_threads
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_delayed_insert_timeout">
delayed_insert_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_delayed_queue_size">
delayed_queue_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Delayed_writes">
Delayed_writes
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Deprecated_use_i_s_processlist_count">
Deprecated_use_i_s_processlist_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Deprecated_use_i_s_processlist_last_timestamp">
Deprecated_use_i_s_processlist_last_timestamp
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_disabled_storage_engines">
disabled_storage_engines
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_disconnect_on_expired_password">
disconnect_on_expired_password
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_div_precision_increment">
div_precision_increment
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_dragnet.log_error_filter_rules">
dragnet.log_error_filter_rules
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_dragnet.Status">
dragnet.Status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_early-plugin-load">
early-plugin-load
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_end_markers_in_json">
end_markers_in_json
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-gtids.html#sysvar_enforce_gtid_consistency">
enforce_gtid_consistency
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_enterprise_encryption.maximum_rsa_key_size">
enterprise_encryption.maximum_rsa_key_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_enterprise_encryption.rsa_support_legacy_padding">
enterprise_encryption.rsa_support_legacy_padding
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_eq_range_index_dive_limit">
eq_range_index_dive_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_error_count">
error_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Error_log_buffered_bytes">
Error_log_buffered_bytes
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Error_log_buffered_events">
Error_log_buffered_events
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Error_log_expired_events">
Error_log_expired_events
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Error_log_latest_write">
Error_log_latest_write
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_event_scheduler">
event_scheduler
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_exit-info">
exit-info
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_explain_format">
explain_format
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_explain_json_format_version">
explain_json_format_version
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_explicit_defaults_for_timestamp">
explicit_defaults_for_timestamp
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_external-locking">
external-locking
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
-
<span class="emphasis">
<em>
Variable
</em>
</span>
:
<a class="link" href="server-system-variables.html#sysvar_skip_external_locking">
skip_external_locking
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_external_user">
external_user
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="federated-storage-engine.html" title="18.8 The FEDERATED Storage Engine">
federated
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="firewall-reference.html#statvar_Firewall_access_denied">
Firewall_access_denied
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="firewall-reference.html#statvar_Firewall_access_granted">
Firewall_access_granted
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="firewall-reference.html#statvar_Firewall_cached_entries">
Firewall_cached_entries
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_flush">
flush
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Flush_commands">
Flush_commands
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_flush_time">
flush_time
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_foreign_key_checks">
foreign_key_checks
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_ft_boolean_syntax">
ft_boolean_syntax
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_ft_max_word_len">
ft_max_word_len
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_ft_min_word_len">
ft_min_word_len
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_ft_query_expansion_limit">
ft_query_expansion_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_ft_stopword_file">
ft_stopword_file
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_gdb">
gdb
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_general_log">
general_log
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_general_log_file">
general_log_file
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_generated_random_password_length">
generated_random_password_length
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Global_connection_memory">
Global_connection_memory
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_global_connection_memory_limit">
global_connection_memory_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_global_connection_memory_tracking">
global_connection_memory_tracking
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_all_consensus_proposals_count">
Gr_all_consensus_proposals_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_all_consensus_time_sum">
Gr_all_consensus_time_sum
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_certification_garbage_collector_count">
Gr_certification_garbage_collector_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_certification_garbage_collector_time_sum">
Gr_certification_garbage_collector_time_sum
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_consensus_bytes_received_sum">
Gr_consensus_bytes_received_sum
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_consensus_bytes_sent_sum">
Gr_consensus_bytes_sent_sum
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_control_messages_sent_bytes_sum">
Gr_control_messages_sent_bytes_sum
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_control_messages_sent_count">
Gr_control_messages_sent_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_control_messages_sent_roundtrip_time_sum">
Gr_control_messages_sent_roundtrip_time_sum
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_data_messages_sent_bytes_sum">
Gr_data_messages_sent_bytes_sum
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_data_messages_sent_count">
Gr_data_messages_sent_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_data_messages_sent_roundtrip_time_sum">
Gr_data_messages_sent_roundtrip_time_sum
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_empty_consensus_proposals_count">
Gr_empty_consensus_proposals_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_extended_consensus_count">
Gr_extended_consensus_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
Gr_flow_control_throttle_active_count
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
Gr_flow_control_throttle_count
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
Gr_flow_control_throttle_last_throttle_timestamp
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
Gr_flow_control_throttle_time_sum
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_last_consensus_end_timestamp">
Gr_last_consensus_end_timestamp
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_total_messages_sent_count">
Gr_total_messages_sent_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_transactions_consistency_after_sync_count">
Gr_transactions_consistency_after_sync_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_transactions_consistency_after_sync_time_sum">
Gr_transactions_consistency_after_sync_time_sum
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_transactions_consistency_after_termination_count">
Gr_transactions_consistency_after_termination_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_transactions_consistency_after_termination_time_sum">
Gr_transactions_consistency_after_termination_time_sum
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_transactions_consistency_before_begin_count">
Gr_transactions_consistency_before_begin_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-status-variables.html#statvar_Gr_transactions_consistency_before_begin_time_sum">
Gr_transactions_consistency_before_begin_time_sum
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_group_concat_max_len">
group_concat_max_len
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_advertise_recovery_endpoints">
group_replication_advertise_recovery_endpoints
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_allow_local_lower_version_join">
group_replication_allow_local_lower_version_join
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_auto_increment_increment">
group_replication_auto_increment_increment
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_autorejoin_tries">
group_replication_autorejoin_tries
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_bootstrap_group">
group_replication_bootstrap_group
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_clone_threshold">
group_replication_clone_threshold
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_communication_debug_options">
group_replication_communication_debug_options
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_communication_max_message_size">
group_replication_communication_max_message_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_communication_stack">
group_replication_communication_stack
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_components_stop_timeout">
group_replication_components_stop_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_compression_threshold">
group_replication_compression_threshold
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_consistency">
group_replication_consistency
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_enforce_update_everywhere_checks">
group_replication_enforce_update_everywhere_checks
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_exit_state_action">
group_replication_exit_state_action
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_flow_control_applier_threshold">
group_replication_flow_control_applier_threshold
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_flow_control_certifier_threshold">
group_replication_flow_control_certifier_threshold
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_flow_control_hold_percent">
group_replication_flow_control_hold_percent
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_flow_control_max_quota">
group_replication_flow_control_max_quota
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_flow_control_member_quota_percent">
group_replication_flow_control_member_quota_percent
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_flow_control_min_quota">
group_replication_flow_control_min_quota
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_flow_control_min_recovery_quota">
group_replication_flow_control_min_recovery_quota
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_flow_control_mode">
group_replication_flow_control_mode
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_flow_control_period">
group_replication_flow_control_period
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_flow_control_release_percent">
group_replication_flow_control_release_percent
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_force_members">
group_replication_force_members
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_group_name">
group_replication_group_name
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_group_seeds">
group_replication_group_seeds
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_gtid_assignment_block_size">
group_replication_gtid_assignment_block_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_ip_allowlist">
group_replication_ip_allowlist
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_local_address">
group_replication_local_address
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_member_expel_timeout">
group_replication_member_expel_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_member_weight">
group_replication_member_weight
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_message_cache_size">
group_replication_message_cache_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_paxos_single_leader">
group_replication_paxos_single_leader
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_poll_spin_loops">
group_replication_poll_spin_loops
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_preemptive_garbage_collection">
group_replication_preemptive_garbage_collection
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_preemptive_garbage_collection_rows_threshold">
group_replication_preemptive_garbage_collection_rows_threshold
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_compression_algorithms">
group_replication_recovery_compression_algorithms
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_get_public_key">
group_replication_recovery_get_public_key
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_public_key_path">
group_replication_recovery_public_key_path
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_reconnect_interval">
group_replication_recovery_reconnect_interval
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_retry_count">
group_replication_recovery_retry_count
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_ssl_ca">
group_replication_recovery_ssl_ca
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_ssl_capath">
group_replication_recovery_ssl_capath
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_ssl_cert">
group_replication_recovery_ssl_cert
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_ssl_cipher">
group_replication_recovery_ssl_cipher
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_ssl_crl">
group_replication_recovery_ssl_crl
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_ssl_crlpath">
group_replication_recovery_ssl_crlpath
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_ssl_key">
group_replication_recovery_ssl_key
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_ssl_verify_server_cert">
group_replication_recovery_ssl_verify_server_cert
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_tls_ciphersuites">
group_replication_recovery_tls_ciphersuites
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_tls_version">
group_replication_recovery_tls_version
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_use_ssl">
group_replication_recovery_use_ssl
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_recovery_zstd_compression_level">
group_replication_recovery_zstd_compression_level
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_single_primary_mode">
group_replication_single_primary_mode
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_ssl_mode">
group_replication_ssl_mode
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_start_on_boot">
group_replication_start_on_boot
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_tls_source">
group_replication_tls_source
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_transaction_size_limit">
group_replication_transaction_size_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_unreachable_majority_timeout">
group_replication_unreachable_majority_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="group-replication-system-variables.html#sysvar_group_replication_view_change_uuid">
group_replication_view_change_uuid
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-gtids.html#sysvar_gtid_executed">
gtid_executed
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-gtids.html#sysvar_gtid_executed_compression_period">
gtid_executed_compression_period
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-gtids.html#sysvar_gtid_mode">
gtid_mode
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-gtids.html#sysvar_gtid_next">
gtid_next
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-gtids.html#sysvar_gtid_owned">
gtid_owned
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-gtids.html#sysvar_gtid_purged">
gtid_purged
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_commit">
Handler_commit
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_delete">
Handler_delete
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Handler_discover">
Handler_discover
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_external_lock">
Handler_external_lock
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_mrr_init">
Handler_mrr_init
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_prepare">
Handler_prepare
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_read_first">
Handler_read_first
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_read_key">
Handler_read_key
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_read_last">
Handler_read_last
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_read_next">
Handler_read_next
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_read_prev">
Handler_read_prev
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_read_rnd">
Handler_read_rnd
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_read_rnd_next">
Handler_read_rnd_next
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_rollback">
Handler_rollback
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_savepoint">
Handler_savepoint
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_savepoint_rollback">
Handler_savepoint_rollback
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_update">
Handler_update
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Handler_write">
Handler_write
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_have_compress">
have_compress
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_have_dynamic_loading">
have_dynamic_loading
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_have_geometry">
have_geometry
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_have_profiling">
have_profiling
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_have_query_cache">
have_query_cache
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_have_rtree_keys">
have_rtree_keys
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_have_statement_timeout">
have_statement_timeout
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_have_symlink">
have_symlink
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_help">
help
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_histogram_generation_max_mem_size">
histogram_generation_max_mem_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_host_cache_size">
host_cache_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_hostname">
hostname
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_identity">
identity
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#sysvar_immediate_server_version">
immediate_server_version
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_information_schema_stats_expiry">
information_schema_stats_expiry
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_init_connect">
init_connect
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_init_file">
init_file
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_init_replica">
init_replica
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_init_slave">
init_slave
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_initialize">
initialize
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_initialize-insecure">
initialize-insecure
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_adaptive_flushing">
innodb_adaptive_flushing
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_adaptive_flushing_lwm">
innodb_adaptive_flushing_lwm
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_adaptive_hash_index">
innodb_adaptive_hash_index
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_adaptive_hash_index_parts">
innodb_adaptive_hash_index_parts
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_adaptive_max_sleep_delay">
innodb_adaptive_max_sleep_delay
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_autoextend_increment">
innodb_autoextend_increment
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_autoinc_lock_mode">
innodb_autoinc_lock_mode
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_background_drop_list_empty">
innodb_background_drop_list_empty
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_bytes_data">
Innodb_buffer_pool_bytes_data
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_bytes_dirty">
Innodb_buffer_pool_bytes_dirty
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_chunk_size">
innodb_buffer_pool_chunk_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_debug">
innodb_buffer_pool_debug
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_dump_at_shutdown">
innodb_buffer_pool_dump_at_shutdown
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_dump_now">
innodb_buffer_pool_dump_now
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_dump_pct">
innodb_buffer_pool_dump_pct
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_dump_status">
Innodb_buffer_pool_dump_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_filename">
innodb_buffer_pool_filename
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_in_core_file">
innodb_buffer_pool_in_core_file
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_instances">
innodb_buffer_pool_instances
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_load_abort">
innodb_buffer_pool_load_abort
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_load_at_startup">
innodb_buffer_pool_load_at_startup
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_load_now">
innodb_buffer_pool_load_now
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_load_status">
Innodb_buffer_pool_load_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_pages_data">
Innodb_buffer_pool_pages_data
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_pages_dirty">
Innodb_buffer_pool_pages_dirty
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_pages_flushed">
Innodb_buffer_pool_pages_flushed
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_pages_free">
Innodb_buffer_pool_pages_free
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_pages_latched">
Innodb_buffer_pool_pages_latched
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_pages_misc">
Innodb_buffer_pool_pages_misc
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_pages_total">
Innodb_buffer_pool_pages_total
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_read_ahead">
Innodb_buffer_pool_read_ahead
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_read_ahead_evicted">
Innodb_buffer_pool_read_ahead_evicted
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_read_ahead_rnd">
Innodb_buffer_pool_read_ahead_rnd
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_read_requests">
Innodb_buffer_pool_read_requests
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_reads">
Innodb_buffer_pool_reads
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_resize_status">
Innodb_buffer_pool_resize_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_resize_status_code">
Innodb_buffer_pool_resize_status_code
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_resize_status_progress">
Innodb_buffer_pool_resize_status_progress
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_size">
innodb_buffer_pool_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_wait_free">
Innodb_buffer_pool_wait_free
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_buffer_pool_write_requests">
Innodb_buffer_pool_write_requests
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_change_buffer_max_size">
innodb_change_buffer_max_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_change_buffering">
innodb_change_buffering
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_change_buffering_debug">
innodb_change_buffering_debug
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_checkpoint_disabled">
innodb_checkpoint_disabled
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_checksum_algorithm">
innodb_checksum_algorithm
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_cmp_per_index_enabled">
innodb_cmp_per_index_enabled
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_commit_concurrency">
innodb_commit_concurrency
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_compress_debug">
innodb_compress_debug
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_compression_failure_threshold_pct">
innodb_compression_failure_threshold_pct
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_compression_level">
innodb_compression_level
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_compression_pad_pct_max">
innodb_compression_pad_pct_max
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_concurrency_tickets">
innodb_concurrency_tickets
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_data_file_path">
innodb_data_file_path
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_data_fsyncs">
Innodb_data_fsyncs
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_data_home_dir">
innodb_data_home_dir
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_data_pending_fsyncs">
Innodb_data_pending_fsyncs
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_data_pending_reads">
Innodb_data_pending_reads
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_data_pending_writes">
Innodb_data_pending_writes
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_data_read">
Innodb_data_read
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_data_reads">
Innodb_data_reads
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_data_writes">
Innodb_data_writes
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_data_written">
Innodb_data_written
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_dblwr_pages_written">
Innodb_dblwr_pages_written
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_dblwr_writes">
Innodb_dblwr_writes
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_ddl_buffer_size">
innodb_ddl_buffer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_ddl_log_crash_reset_debug">
innodb_ddl_log_crash_reset_debug
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_ddl_threads">
innodb_ddl_threads
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_deadlock_detect">
innodb_deadlock_detect
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#option_mysqld_innodb-dedicated-server">
innodb_dedicated_server
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_default_row_format">
innodb_default_row_format
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_directories">
innodb_directories
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_disable_sort_file_cache">
innodb_disable_sort_file_cache
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_doublewrite">
innodb_doublewrite
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_doublewrite_batch_size">
innodb_doublewrite_batch_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_doublewrite_dir">
innodb_doublewrite_dir
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_doublewrite_files">
innodb_doublewrite_files
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_doublewrite_pages">
innodb_doublewrite_pages
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_extend_and_initialize">
innodb_extend_and_initialize
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_fast_shutdown">
innodb_fast_shutdown
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_fil_make_page_dirty_debug">
innodb_fil_make_page_dirty_debug
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_file_per_table">
innodb_file_per_table
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_fill_factor">
innodb_fill_factor
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_flush_log_at_timeout">
innodb_flush_log_at_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_flush_log_at_trx_commit">
innodb_flush_log_at_trx_commit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_flush_method">
innodb_flush_method
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_flush_neighbors">
innodb_flush_neighbors
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_flush_sync">
innodb_flush_sync
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_flushing_avg_loops">
innodb_flushing_avg_loops
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_force_load_corrupted">
innodb_force_load_corrupted
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_force_recovery">
innodb_force_recovery
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_fsync_threshold">
innodb_fsync_threshold
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_ft_aux_table">
innodb_ft_aux_table
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_ft_cache_size">
innodb_ft_cache_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_ft_enable_diag_print">
innodb_ft_enable_diag_print
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_ft_enable_stopword">
innodb_ft_enable_stopword
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_ft_max_token_size">
innodb_ft_max_token_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_ft_min_token_size">
innodb_ft_min_token_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_ft_num_word_optimize">
innodb_ft_num_word_optimize
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_ft_result_cache_limit">
innodb_ft_result_cache_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_ft_server_stopword_table">
innodb_ft_server_stopword_table
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_ft_sort_pll_degree">
innodb_ft_sort_pll_degree
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_ft_total_cache_size">
innodb_ft_total_cache_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_ft_user_stopword_table">
innodb_ft_user_stopword_table
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_have_atomic_builtins">
Innodb_have_atomic_builtins
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_idle_flush_pct">
innodb_idle_flush_pct
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_io_capacity">
innodb_io_capacity
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_io_capacity_max">
innodb_io_capacity_max
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_limit_optimistic_insert_debug">
innodb_limit_optimistic_insert_debug
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_lock_wait_timeout">
innodb_lock_wait_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_log_buffer_size">
innodb_log_buffer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_log_checkpoint_fuzzy_now">
innodb_log_checkpoint_fuzzy_now
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_log_checkpoint_now">
innodb_log_checkpoint_now
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_log_checksums">
innodb_log_checksums
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_log_compressed_pages">
innodb_log_compressed_pages
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_log_file_size">
innodb_log_file_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_log_files_in_group">
innodb_log_files_in_group
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_log_group_home_dir">
innodb_log_group_home_dir
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_log_spin_cpu_abs_lwm">
innodb_log_spin_cpu_abs_lwm
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_log_spin_cpu_pct_hwm">
innodb_log_spin_cpu_pct_hwm
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_log_wait_for_flush_spin_hwm">
innodb_log_wait_for_flush_spin_hwm
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_log_waits">
Innodb_log_waits
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_log_write_ahead_size">
innodb_log_write_ahead_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_log_write_requests">
Innodb_log_write_requests
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_log_writer_threads">
innodb_log_writer_threads
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_log_writes">
Innodb_log_writes
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_lru_scan_depth">
innodb_lru_scan_depth
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_max_dirty_pages_pct">
innodb_max_dirty_pages_pct
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_max_dirty_pages_pct_lwm">
innodb_max_dirty_pages_pct_lwm
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_max_purge_lag">
innodb_max_purge_lag
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_max_purge_lag_delay">
innodb_max_purge_lag_delay
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_max_undo_log_size">
innodb_max_undo_log_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_merge_threshold_set_all_debug">
innodb_merge_threshold_set_all_debug
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_monitor_disable">
innodb_monitor_disable
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_monitor_enable">
innodb_monitor_enable
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_monitor_reset">
innodb_monitor_reset
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_monitor_reset_all">
innodb_monitor_reset_all
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_num_open_files">
Innodb_num_open_files
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_numa_interleave">
innodb_numa_interleave
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_old_blocks_pct">
innodb_old_blocks_pct
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_old_blocks_time">
innodb_old_blocks_time
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_online_alter_log_max_size">
innodb_online_alter_log_max_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_open_files">
innodb_open_files
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_optimize_fulltext_only">
innodb_optimize_fulltext_only
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_os_log_fsyncs">
Innodb_os_log_fsyncs
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_os_log_pending_fsyncs">
Innodb_os_log_pending_fsyncs
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_os_log_pending_writes">
Innodb_os_log_pending_writes
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_os_log_written">
Innodb_os_log_written
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_page_cleaners">
innodb_page_cleaners
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_page_size">
Innodb_page_size
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_page_size">
innodb_page_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_pages_created">
Innodb_pages_created
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_pages_read">
Innodb_pages_read
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_pages_written">
Innodb_pages_written
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_parallel_read_threads">
innodb_parallel_read_threads
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_print_all_deadlocks">
innodb_print_all_deadlocks
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_print_ddl_logs">
innodb_print_ddl_logs
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_purge_batch_size">
innodb_purge_batch_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_purge_rseg_truncate_frequency">
innodb_purge_rseg_truncate_frequency
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_purge_threads">
innodb_purge_threads
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_random_read_ahead">
innodb_random_read_ahead
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_read_ahead_threshold">
innodb_read_ahead_threshold
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_read_io_threads">
innodb_read_io_threads
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_read_only">
innodb_read_only
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_redo_log_archive_dirs">
innodb_redo_log_archive_dirs
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_redo_log_capacity">
innodb_redo_log_capacity
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_capacity_resized">
Innodb_redo_log_capacity_resized
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_checkpoint_lsn">
Innodb_redo_log_checkpoint_lsn
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_current_lsn">
Innodb_redo_log_current_lsn
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_enabled">
Innodb_redo_log_enabled
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_redo_log_encrypt">
innodb_redo_log_encrypt
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_flushed_to_disk_lsn">
Innodb_redo_log_flushed_to_disk_lsn
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_logical_size">
Innodb_redo_log_logical_size
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_physical_size">
Innodb_redo_log_physical_size
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_read_only">
Innodb_redo_log_read_only
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_resize_status">
Innodb_redo_log_resize_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_uuid">
Innodb_redo_log_uuid
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_replication_delay">
innodb_replication_delay
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_rollback_on_timeout">
innodb_rollback_on_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_rollback_segments">
innodb_rollback_segments
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_row_lock_current_waits">
Innodb_row_lock_current_waits
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_row_lock_time">
Innodb_row_lock_time
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_row_lock_time_avg">
Innodb_row_lock_time_avg
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_row_lock_time_max">
Innodb_row_lock_time_max
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_row_lock_waits">
Innodb_row_lock_waits
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_rows_deleted">
Innodb_rows_deleted
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_rows_inserted">
Innodb_rows_inserted
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_rows_read">
Innodb_rows_read
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_rows_updated">
Innodb_rows_updated
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_saved_page_number_debug">
innodb_saved_page_number_debug
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_segment_reserve_factor">
innodb_segment_reserve_factor
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_sort_buffer_size">
innodb_sort_buffer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_spin_wait_delay">
innodb_spin_wait_delay
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_spin_wait_pause_multiplier">
innodb_spin_wait_pause_multiplier
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_stats_auto_recalc">
innodb_stats_auto_recalc
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_stats_include_delete_marked">
innodb_stats_include_delete_marked
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_stats_method">
innodb_stats_method
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_stats_on_metadata">
innodb_stats_on_metadata
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_stats_persistent">
innodb_stats_persistent
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_stats_persistent_sample_pages">
innodb_stats_persistent_sample_pages
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_stats_transient_sample_pages">
innodb_stats_transient_sample_pages
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#option_mysqld_innodb-status-file">
innodb-status-file
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_status_output">
innodb_status_output
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_status_output_locks">
innodb_status_output_locks
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_strict_mode">
innodb_strict_mode
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_sync_array_size">
innodb_sync_array_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_sync_debug">
innodb_sync_debug
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_sync_spin_loops">
innodb_sync_spin_loops
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_system_rows_deleted">
Innodb_system_rows_deleted
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_system_rows_inserted">
Innodb_system_rows_inserted
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_system_rows_read">
Innodb_system_rows_read
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_system_rows_updated">
Innodb_system_rows_updated
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_table_locks">
innodb_table_locks
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_temp_data_file_path">
innodb_temp_data_file_path
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_temp_tablespaces_dir">
innodb_temp_tablespaces_dir
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_thread_concurrency">
innodb_thread_concurrency
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_thread_sleep_delay">
innodb_thread_sleep_delay
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_tmpdir">
innodb_tmpdir
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_truncated_status_writes">
Innodb_truncated_status_writes
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_trx_purge_view_update_only_debug">
innodb_trx_purge_view_update_only_debug
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_trx_rseg_n_slots_debug">
innodb_trx_rseg_n_slots_debug
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_undo_directory">
innodb_undo_directory
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_undo_log_encrypt">
innodb_undo_log_encrypt
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_undo_log_truncate">
innodb_undo_log_truncate
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_undo_tablespaces">
innodb_undo_tablespaces
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_undo_tablespaces_active">
Innodb_undo_tablespaces_active
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_undo_tablespaces_explicit">
Innodb_undo_tablespaces_explicit
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_undo_tablespaces_implicit">
Innodb_undo_tablespaces_implicit
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Innodb_undo_tablespaces_total">
Innodb_undo_tablespaces_total
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_use_fdatasync">
innodb_use_fdatasync
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_use_native_aio">
innodb_use_native_aio
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_validate_tablespace_paths">
innodb_validate_tablespace_paths
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_version">
innodb_version
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="innodb-parameters.html#sysvar_innodb_write_io_threads">
innodb_write_io_threads
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_insert_id">
insert_id
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_install">
install
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_install-manual">
install-manual
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_interactive_timeout">
interactive_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_internal_tmp_mem_storage_engine">
internal_tmp_mem_storage_engine
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_join_buffer_size">
join_buffer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_keep_files_on_create">
keep_files_on_create
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Key_blocks_not_flushed">
Key_blocks_not_flushed
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Key_blocks_unused">
Key_blocks_unused
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Key_blocks_used">
Key_blocks_used
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_key_buffer_size">
key_buffer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_key_cache_age_threshold">
key_cache_age_threshold
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_key_cache_block_size">
key_cache_block_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_key_cache_division_limit">
key_cache_division_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Key_read_requests">
Key_read_requests
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Key_reads">
Key_reads
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Key_write_requests">
Key_write_requests
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Key_writes">
Key_writes
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_aws_cmk_id">
keyring_aws_cmk_id
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_aws_conf_file">
keyring_aws_conf_file
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_aws_data_file">
keyring_aws_data_file
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_aws_region">
keyring_aws_region
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_hashicorp_auth_path">
keyring_hashicorp_auth_path
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_hashicorp_ca_path">
keyring_hashicorp_ca_path
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_hashicorp_caching">
keyring_hashicorp_caching
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_hashicorp_commit_auth_path">
keyring_hashicorp_commit_auth_path
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_hashicorp_commit_ca_path">
keyring_hashicorp_commit_ca_path
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_hashicorp_commit_caching">
keyring_hashicorp_commit_caching
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_hashicorp_commit_role_id">
keyring_hashicorp_commit_role_id
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_hashicorp_commit_server_url">
keyring_hashicorp_commit_server_url
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_hashicorp_commit_store_path">
keyring_hashicorp_commit_store_path
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_hashicorp_role_id">
keyring_hashicorp_role_id
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_hashicorp_secret_id">
keyring_hashicorp_secret_id
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_hashicorp_server_url">
keyring_hashicorp_server_url
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_hashicorp_store_path">
keyring_hashicorp_store_path
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-options.html#option_mysqld_keyring-migration-destination">
keyring-migration-destination
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-options.html#option_mysqld_keyring-migration-from-component">
keyring-migration-from-component
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-options.html#option_mysqld_keyring-migration-host">
keyring-migration-host
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-options.html#option_mysqld_keyring-migration-password">
keyring-migration-password
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-options.html#option_mysqld_keyring-migration-port">
keyring-migration-port
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-options.html#option_mysqld_keyring-migration-socket">
keyring-migration-socket
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-options.html#option_mysqld_keyring-migration-source">
keyring-migration-source
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-options.html#option_mysqld_keyring-migration-to-component">
keyring-migration-to-component
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-options.html#option_mysqld_keyring-migration-user">
keyring-migration-user
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_okv_conf_dir">
keyring_okv_conf_dir
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="keyring-system-variables.html#sysvar_keyring_operations">
keyring_operations
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_large_files_support">
large_files_support
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_large_page_size">
large_page_size
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_large-pages">
large_pages
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_last_insert_id">
last_insert_id
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Last_query_cost">
Last_query_cost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Last_query_partial_plans">
Last_query_partial_plans
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_lc-messages">
lc_messages
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_lc-messages-dir">
lc_messages_dir
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_lc_time_names">
lc_time_names
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_license">
license
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_local_infile">
local_infile
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_local-service">
local-service
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="lock-order-tool.html#sysvar_lock_order">
lock_order
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="lock-order-tool.html#sysvar_lock_order_debug_loop">
lock_order_debug_loop
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="lock-order-tool.html#sysvar_lock_order_debug_missing_arc">
lock_order_debug_missing_arc
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="lock-order-tool.html#sysvar_lock_order_debug_missing_key">
lock_order_debug_missing_key
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="lock-order-tool.html#sysvar_lock_order_debug_missing_unlock">
lock_order_debug_missing_unlock
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="lock-order-tool.html#sysvar_lock_order_dependencies">
lock_order_dependencies
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="lock-order-tool.html#sysvar_lock_order_extra_dependencies">
lock_order_extra_dependencies
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="lock-order-tool.html#sysvar_lock_order_output_directory">
lock_order_output_directory
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="lock-order-tool.html#sysvar_lock_order_print_txt">
lock_order_print_txt
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="lock-order-tool.html#sysvar_lock_order_trace_loop">
lock_order_trace_loop
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="lock-order-tool.html#sysvar_lock_order_trace_missing_arc">
lock_order_trace_missing_arc
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="lock-order-tool.html#sysvar_lock_order_trace_missing_key">
lock_order_trace_missing_key
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="lock-order-tool.html#sysvar_lock_order_trace_missing_unlock">
lock_order_trace_missing_unlock
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_lock_wait_timeout">
lock_wait_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Locked_connects">
Locked_connects
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_locked_in_memory">
locked_in_memory
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#option_mysqld_log-bin">
log-bin
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_log_bin">
log_bin
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_log_bin_basename">
log_bin_basename
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#option_mysqld_log-bin-index">
log_bin_index
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_log_bin_trust_function_creators">
log_bin_trust_function_creators
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_log-error">
log_error
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_log_error_services">
log_error_services
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_log_error_suppression_list">
log_error_suppression_list
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_log_error_verbosity">
log_error_verbosity
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_log-isam">
log-isam
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_log_output">
log_output
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_log_queries_not_using_indexes">
log_queries_not_using_indexes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_log-raw">
log_raw
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_log_replica_updates">
log_replica_updates
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_log-short-format">
log-short-format
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_log_slave_updates">
log_slave_updates
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_log_slow_admin_statements">
log_slow_admin_statements
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_log_slow_extra">
log_slow_extra
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_log_slow_replica_statements">
log_slow_replica_statements
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_log_slow_slave_statements">
log_slow_slave_statements
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_log_statements_unsafe_for_binlog">
log_statements_unsafe_for_binlog
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_log-tc">
log-tc
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_log-tc-size">
log-tc-size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_log_throttle_queries_not_using_indexes">
log_throttle_queries_not_using_indexes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_log_timestamps">
log_timestamps
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_long_query_time">
long_query_time
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_low_priority_updates">
low_priority_updates
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_lower_case_file_system">
lower_case_file_system
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_lower_case_table_names">
lower_case_table_names
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_mandatory_roles">
mandatory_roles
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#option_mysqld_master-retry-count">
master-retry-count
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_master_verify_checksum">
master_verify_checksum
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_allowed_packet">
max_allowed_packet
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_max_binlog_cache_size">
max_binlog_cache_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#option_mysqld_max-binlog-dump-events">
max-binlog-dump-events
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_max_binlog_size">
max_binlog_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_max_binlog_stmt_cache_size">
max_binlog_stmt_cache_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_connect_errors">
max_connect_errors
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_connections">
max_connections
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_delayed_threads">
max_delayed_threads
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_digest_length">
max_digest_length
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_error_count">
max_error_count
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_execution_time">
max_execution_time
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Max_execution_time_exceeded">
Max_execution_time_exceeded
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Max_execution_time_set">
Max_execution_time_set
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Max_execution_time_set_failed">
Max_execution_time_set_failed
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_heap_table_size">
max_heap_table_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_insert_delayed_threads">
max_insert_delayed_threads
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_join_size">
max_join_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_length_for_sort_data">
max_length_for_sort_data
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_points_in_geometry">
max_points_in_geometry
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_prepared_stmt_count">
max_prepared_stmt_count
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_max_relay_log_size">
max_relay_log_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_seeks_for_key">
max_seeks_for_key
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_sort_length">
max_sort_length
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_sp_recursion_depth">
max_sp_recursion_depth
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Max_used_connections">
Max_used_connections
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Max_used_connections_time">
Max_used_connections_time
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_user_connections">
max_user_connections
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_max_write_lock_count">
max_write_lock_count
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_mecab_charset">
mecab_charset
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_mecab_rc_file">
mecab_rc_file
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_memlock">
memlock
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
-
<span class="emphasis">
<em>
Variable
</em>
</span>
:
<a class="link" href="server-system-variables.html#sysvar_locked_in_memory">
locked_in_memory
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_min_examined_row_limit">
min_examined_row_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_myisam-block-size">
myisam-block-size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_myisam_data_pointer_size">
myisam_data_pointer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_myisam_max_sort_file_size">
myisam_max_sort_file_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_myisam_mmap_size">
myisam_mmap_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_myisam_recover_options">
myisam_recover_options
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_myisam_sort_buffer_size">
myisam_sort_buffer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_myisam_stats_method">
myisam_stats_method
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_myisam_use_mmap">
myisam_use_mmap
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="firewall-reference.html#sysvar_mysql_firewall_database">
mysql_firewall_database
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="firewall-reference.html#sysvar_mysql_firewall_mode">
mysql_firewall_mode
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="firewall-reference.html#sysvar_mysql_firewall_reload_interval_seconds">
mysql_firewall_reload_interval_seconds
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="firewall-reference.html#sysvar_mysql_firewall_trace">
mysql_firewall_trace
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_mysql-native-password">
mysql-native-password
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_mysql_native_password_proxy_users">
mysql_native_password_proxy_users
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#option_mysqld_mysqlx">
mysqlx
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_aborted_clients">
Mysqlx_aborted_clients
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_address">
Mysqlx_address
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_bind_address">
mysqlx_bind_address
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_bytes_received">
Mysqlx_bytes_received
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_bytes_received_compressed_payload">
Mysqlx_bytes_received_compressed_payload
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_bytes_received_uncompressed_frame">
Mysqlx_bytes_received_uncompressed_frame
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_bytes_sent">
Mysqlx_bytes_sent
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_bytes_sent_compressed_payload">
Mysqlx_bytes_sent_compressed_payload
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_bytes_sent_uncompressed_frame">
Mysqlx_bytes_sent_uncompressed_frame
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_compression_algorithm">
Mysqlx_compression_algorithm
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_compression_algorithms">
mysqlx_compression_algorithms
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_compression_level">
Mysqlx_compression_level
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_connect_timeout">
mysqlx_connect_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_connection_accept_errors">
Mysqlx_connection_accept_errors
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_connection_errors">
Mysqlx_connection_errors
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_connections_accepted">
Mysqlx_connections_accepted
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_connections_closed">
Mysqlx_connections_closed
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_connections_rejected">
Mysqlx_connections_rejected
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_crud_create_view">
Mysqlx_crud_create_view
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_crud_delete">
Mysqlx_crud_delete
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_crud_drop_view">
Mysqlx_crud_drop_view
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_crud_find">
Mysqlx_crud_find
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_crud_insert">
Mysqlx_crud_insert
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_crud_modify_view">
Mysqlx_crud_modify_view
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_crud_update">
Mysqlx_crud_update
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_cursor_close">
Mysqlx_cursor_close
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_cursor_fetch">
Mysqlx_cursor_fetch
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_cursor_open">
Mysqlx_cursor_open
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_deflate_default_compression_level">
mysqlx_deflate_default_compression_level
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_deflate_max_client_compression_level">
mysqlx_deflate_max_client_compression_level
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_document_id_unique_prefix">
mysqlx_document_id_unique_prefix
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_enable_hello_notice">
mysqlx_enable_hello_notice
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_errors_sent">
Mysqlx_errors_sent
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_errors_unknown_message_type">
Mysqlx_errors_unknown_message_type
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_expect_close">
Mysqlx_expect_close
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_expect_open">
Mysqlx_expect_open
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_idle_worker_thread_timeout">
mysqlx_idle_worker_thread_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_init_error">
Mysqlx_init_error
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_interactive_timeout">
mysqlx_interactive_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_lz4_default_compression_level">
mysqlx_lz4_default_compression_level
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_lz4_max_client_compression_level">
mysqlx_lz4_max_client_compression_level
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_max_allowed_packet">
mysqlx_max_allowed_packet
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_max_connections">
mysqlx_max_connections
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_messages_sent">
Mysqlx_messages_sent
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_min_worker_threads">
mysqlx_min_worker_threads
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_notice_global_sent">
Mysqlx_notice_global_sent
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_notice_other_sent">
Mysqlx_notice_other_sent
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_notice_warning_sent">
Mysqlx_notice_warning_sent
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_notified_by_group_replication">
Mysqlx_notified_by_group_replication
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_port">
Mysqlx_port
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_port">
mysqlx_port
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_port_open_timeout">
mysqlx_port_open_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_prep_deallocate">
Mysqlx_prep_deallocate
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_prep_execute">
Mysqlx_prep_execute
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_prep_prepare">
Mysqlx_prep_prepare
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_read_timeout">
mysqlx_read_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_rows_sent">
Mysqlx_rows_sent
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_sessions">
Mysqlx_sessions
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_sessions_accepted">
Mysqlx_sessions_accepted
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_sessions_closed">
Mysqlx_sessions_closed
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_sessions_fatal_error">
Mysqlx_sessions_fatal_error
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_sessions_killed">
Mysqlx_sessions_killed
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_sessions_rejected">
Mysqlx_sessions_rejected
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_socket">
Mysqlx_socket
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_socket">
mysqlx_socket
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_ssl_accept_renegotiates">
Mysqlx_ssl_accept_renegotiates
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_ssl_accepts">
Mysqlx_ssl_accepts
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_ssl_active">
Mysqlx_ssl_active
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_ssl_ca">
mysqlx_ssl_ca
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_ssl_capath">
mysqlx_ssl_capath
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_ssl_cert">
mysqlx_ssl_cert
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_ssl_cipher">
Mysqlx_ssl_cipher
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_ssl_cipher">
mysqlx_ssl_cipher
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_ssl_cipher_list">
Mysqlx_ssl_cipher_list
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_ssl_crl">
mysqlx_ssl_crl
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_ssl_crlpath">
mysqlx_ssl_crlpath
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_ssl_ctx_verify_depth">
Mysqlx_ssl_ctx_verify_depth
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_ssl_ctx_verify_mode">
Mysqlx_ssl_ctx_verify_mode
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_ssl_finished_accepts">
Mysqlx_ssl_finished_accepts
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_ssl_key">
mysqlx_ssl_key
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_ssl_server_not_after">
Mysqlx_ssl_server_not_after
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_ssl_server_not_before">
Mysqlx_ssl_server_not_before
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_ssl_verify_depth">
Mysqlx_ssl_verify_depth
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_ssl_verify_mode">
Mysqlx_ssl_verify_mode
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_ssl_version">
Mysqlx_ssl_version
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_create_collection">
Mysqlx_stmt_create_collection
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_create_collection_index">
Mysqlx_stmt_create_collection_index
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_disable_notices">
Mysqlx_stmt_disable_notices
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_drop_collection">
Mysqlx_stmt_drop_collection
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_drop_collection_index">
Mysqlx_stmt_drop_collection_index
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_enable_notices">
Mysqlx_stmt_enable_notices
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_ensure_collection">
Mysqlx_stmt_ensure_collection
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_execute_mysqlx">
Mysqlx_stmt_execute_mysqlx
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_execute_sql">
Mysqlx_stmt_execute_sql
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_execute_xplugin">
Mysqlx_stmt_execute_xplugin
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_get_collection_options">
Mysqlx_stmt_get_collection_options
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_kill_client">
Mysqlx_stmt_kill_client
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_list_clients">
Mysqlx_stmt_list_clients
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_list_notices">
Mysqlx_stmt_list_notices
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_list_objects">
Mysqlx_stmt_list_objects
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_modify_collection_options">
Mysqlx_stmt_modify_collection_options
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_stmt_ping">
Mysqlx_stmt_ping
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_wait_timeout">
mysqlx_wait_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_worker_threads">
Mysqlx_worker_threads
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-status-variables.html#statvar_Mysqlx_worker_threads_active">
Mysqlx_worker_threads_active
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_write_timeout">
mysqlx_write_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_zstd_default_compression_level">
mysqlx_zstd_default_compression_level
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_zstd_max_client_compression_level">
mysqlx_zstd_max_client_compression_level
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_named_pipe">
named_pipe
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_named_pipe_full_access_group">
named_pipe_full_access_group
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-allow-copying-alter-table">
ndb_allow_copying_alter_table
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_adaptive_send_deferred_count">
Ndb_api_adaptive_send_deferred_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_adaptive_send_deferred_count_replica">
Ndb_api_adaptive_send_deferred_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_adaptive_send_deferred_count_session">
Ndb_api_adaptive_send_deferred_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_adaptive_send_deferred_count_slave">
Ndb_api_adaptive_send_deferred_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_adaptive_send_forced_count">
Ndb_api_adaptive_send_forced_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_adaptive_send_forced_count_replica">
Ndb_api_adaptive_send_forced_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_adaptive_send_forced_count_session">
Ndb_api_adaptive_send_forced_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_adaptive_send_forced_count_slave">
Ndb_api_adaptive_send_forced_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_adaptive_send_unforced_count">
Ndb_api_adaptive_send_unforced_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_adaptive_send_unforced_count_replica">
Ndb_api_adaptive_send_unforced_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_adaptive_send_unforced_count_session">
Ndb_api_adaptive_send_unforced_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_adaptive_send_unforced_count_slave">
Ndb_api_adaptive_send_unforced_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_bytes_received_count">
Ndb_api_bytes_received_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_bytes_received_count_replica">
Ndb_api_bytes_received_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_bytes_received_count_session">
Ndb_api_bytes_received_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_bytes_received_count_slave">
Ndb_api_bytes_received_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_bytes_sent_count">
Ndb_api_bytes_sent_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_bytes_sent_count_replica">
Ndb_api_bytes_sent_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_bytes_sent_count_session">
Ndb_api_bytes_sent_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_bytes_sent_count_slave">
Ndb_api_bytes_sent_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_event_bytes_count">
Ndb_api_event_bytes_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_event_bytes_count_injector">
Ndb_api_event_bytes_count_injector
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_event_data_count">
Ndb_api_event_data_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_event_data_count_injector">
Ndb_api_event_data_count_injector
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_event_nondata_count">
Ndb_api_event_nondata_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_event_nondata_count_injector">
Ndb_api_event_nondata_count_injector
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_pk_op_count">
Ndb_api_pk_op_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_pk_op_count_replica">
Ndb_api_pk_op_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_pk_op_count_session">
Ndb_api_pk_op_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_pk_op_count_slave">
Ndb_api_pk_op_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_pruned_scan_count">
Ndb_api_pruned_scan_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_pruned_scan_count_replica">
Ndb_api_pruned_scan_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_pruned_scan_count_session">
Ndb_api_pruned_scan_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_pruned_scan_count_slave">
Ndb_api_pruned_scan_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_range_scan_count">
Ndb_api_range_scan_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_range_scan_count_replica">
Ndb_api_range_scan_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_range_scan_count_session">
Ndb_api_range_scan_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_range_scan_count_slave">
Ndb_api_range_scan_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_read_row_count">
Ndb_api_read_row_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_read_row_count_replica">
Ndb_api_read_row_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_read_row_count_session">
Ndb_api_read_row_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_read_row_count_slave">
Ndb_api_read_row_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_scan_batch_count">
Ndb_api_scan_batch_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_scan_batch_count_replica">
Ndb_api_scan_batch_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_scan_batch_count_session">
Ndb_api_scan_batch_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_scan_batch_count_slave">
Ndb_api_scan_batch_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_table_scan_count">
Ndb_api_table_scan_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_table_scan_count_replica">
Ndb_api_table_scan_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_table_scan_count_session">
Ndb_api_table_scan_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_table_scan_count_slave">
Ndb_api_table_scan_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_abort_count">
Ndb_api_trans_abort_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_abort_count_replica">
Ndb_api_trans_abort_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_abort_count_session">
Ndb_api_trans_abort_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_abort_count_slave">
Ndb_api_trans_abort_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_close_count">
Ndb_api_trans_close_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_close_count_replica">
Ndb_api_trans_close_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_close_count_session">
Ndb_api_trans_close_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_close_count_slave">
Ndb_api_trans_close_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_commit_count">
Ndb_api_trans_commit_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_commit_count_replica">
Ndb_api_trans_commit_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_commit_count_session">
Ndb_api_trans_commit_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_commit_count_slave">
Ndb_api_trans_commit_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_local_read_row_count">
Ndb_api_trans_local_read_row_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_local_read_row_count_replica">
Ndb_api_trans_local_read_row_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_local_read_row_count_session">
Ndb_api_trans_local_read_row_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_local_read_row_count_slave">
Ndb_api_trans_local_read_row_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_start_count">
Ndb_api_trans_start_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_start_count_replica">
Ndb_api_trans_start_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_start_count_session">
Ndb_api_trans_start_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_trans_start_count_slave">
Ndb_api_trans_start_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_uk_op_count">
Ndb_api_uk_op_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_uk_op_count_replica">
Ndb_api_uk_op_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_uk_op_count_session">
Ndb_api_uk_op_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_uk_op_count_slave">
Ndb_api_uk_op_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_wait_exec_complete_count">
Ndb_api_wait_exec_complete_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_wait_exec_complete_count_replica">
Ndb_api_wait_exec_complete_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_wait_exec_complete_count_session">
Ndb_api_wait_exec_complete_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_wait_exec_complete_count_slave">
Ndb_api_wait_exec_complete_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_wait_meta_request_count">
Ndb_api_wait_meta_request_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_wait_meta_request_count_replica">
Ndb_api_wait_meta_request_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_wait_meta_request_count_session">
Ndb_api_wait_meta_request_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_wait_meta_request_count_slave">
Ndb_api_wait_meta_request_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_wait_nanos_count">
Ndb_api_wait_nanos_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_wait_nanos_count_replica">
Ndb_api_wait_nanos_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_wait_nanos_count_session">
Ndb_api_wait_nanos_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_wait_nanos_count_slave">
Ndb_api_wait_nanos_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_wait_scan_result_count">
Ndb_api_wait_scan_result_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_wait_scan_result_count_replica">
Ndb_api_wait_scan_result_count_replica
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_wait_scan_result_count_session">
Ndb_api_wait_scan_result_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_api_wait_scan_result_count_slave">
Ndb_api_wait_scan_result_count_slave
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-applier-allow-skip-epoch">
ndb_applier_allow_skip_epoch
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_autoincrement_prefetch_sz">
ndb_autoincrement_prefetch_sz
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-batch-size">
ndb_batch_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-blob-read-batch-bytes">
ndb_blob_read_batch_bytes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-blob-write-batch-bytes">
ndb_blob_write_batch_bytes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_clear_apply_status">
ndb_clear_apply_status
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-cluster-connection-pool">
ndb_cluster_connection_pool
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-cluster-connection-pool-nodeids">
ndb_cluster_connection_pool_nodeids
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_cluster_node_id">
Ndb_cluster_node_id
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_config_from_host">
Ndb_config_from_host
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_config_from_port">
Ndb_config_from_port
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_config_generation">
Ndb_config_generation
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_fn_epoch">
Ndb_conflict_fn_epoch
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_fn_epoch_trans">
Ndb_conflict_fn_epoch_trans
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_fn_epoch2">
Ndb_conflict_fn_epoch2
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_fn_epoch2_trans">
Ndb_conflict_fn_epoch2_trans
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_fn_max">
Ndb_conflict_fn_max
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_fn_max_del_win">
Ndb_conflict_fn_max_del_win
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_fn_max_del_win_ins">
Ndb_conflict_fn_max_del_win_ins
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_fn_max_ins">
Ndb_conflict_fn_max_ins
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_fn_old">
Ndb_conflict_fn_old
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_last_conflict_epoch">
Ndb_conflict_last_conflict_epoch
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_last_stable_epoch">
Ndb_conflict_last_stable_epoch
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_reflected_op_discard_count">
Ndb_conflict_reflected_op_discard_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_reflected_op_prepare_count">
Ndb_conflict_reflected_op_prepare_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_refresh_op_count">
Ndb_conflict_refresh_op_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_conflict_role">
ndb_conflict_role
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_trans_conflict_commit_count">
Ndb_conflict_trans_conflict_commit_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_trans_detect_iter_count">
Ndb_conflict_trans_detect_iter_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_trans_reject_count">
Ndb_conflict_trans_reject_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_trans_row_conflict_count">
Ndb_conflict_trans_row_conflict_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_conflict_trans_row_reject_count">
Ndb_conflict_trans_row_reject_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-connectstring">
ndb-connectstring
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_data_node_neighbour">
ndb_data_node_neighbour
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_dbg_check_shares">
ndb_dbg_check_shares
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-default-column-format">
ndb_default_column_format
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_default_column_format">
ndb_default_column_format
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-deferred-constraints">
ndb_deferred_constraints
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_deferred_constraints">
ndb_deferred_constraints
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-distribution">
ndb_distribution
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_distribution">
ndb_distribution
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_epoch_delete_delete_count">
Ndb_epoch_delete_delete_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_eventbuffer_free_percent">
ndb_eventbuffer_free_percent
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_eventbuffer_max_alloc">
ndb_eventbuffer_max_alloc
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_execute_count">
Ndb_execute_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_extra_logging">
ndb_extra_logging
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_force_send">
ndb_force_send
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_fully_replicated">
ndb_fully_replicated
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_index_stat_enable">
ndb_index_stat_enable
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_index_stat_option">
ndb_index_stat_option
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_join_pushdown">
ndb_join_pushdown
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_last_commit_epoch_server">
Ndb_last_commit_epoch_server
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_last_commit_epoch_session">
Ndb_last_commit_epoch_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-log-apply-status">
ndb_log_apply_status
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_log_apply_status">
ndb_log_apply_status
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_log_bin">
ndb_log_bin
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_log_binlog_index">
ndb_log_binlog_index
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_log_cache_size">
ndb_log_cache_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-log-empty-epochs">
ndb_log_empty_epochs
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_log_empty_epochs">
ndb_log_empty_epochs
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-log-empty-update">
ndb_log_empty_update
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_log_empty_update">
ndb_log_empty_update
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-log-exclusive-reads">
ndb_log_exclusive_reads
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_log_exclusive_reads">
ndb_log_exclusive_reads
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-log-fail-terminate">
ndb_log_fail_terminate
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-log-orig">
ndb_log_orig
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_log_orig">
ndb_log_orig
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_log_transaction_compression">
ndb_log_transaction_compression
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_log_transaction_compression_level_zstd">
ndb_log_transaction_compression_level_zstd
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-log-transaction-dependency">
ndb_log_transaction_dependency
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-log-transaction-id">
ndb_log_transaction_id
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_log_transaction_id">
ndb_log_transaction_id
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-log-update-as-write">
ndb_log_update_as_write
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-log-update-minimal">
ndb_log_update_minimal
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-log-updated-only">
ndb_log_updated_only
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_metadata_check">
ndb_metadata_check
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_metadata_check_interval">
ndb_metadata_check_interval
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_metadata_detected_count">
Ndb_metadata_detected_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_metadata_excluded_count">
Ndb_metadata_excluded_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_metadata_sync">
ndb_metadata_sync
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_metadata_synced_count">
Ndb_metadata_synced_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-mgm-tls">
ndb_mgm_tls
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
-
<span class="emphasis">
<em>
Variable
</em>
</span>
: yes
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-mgmd-host">
ndb-mgmd-host
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-nodeid">
ndb_nodeid
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_number_of_data_nodes">
Ndb_number_of_data_nodes
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-optimization-delay">
ndb_optimization_delay
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-optimized-node-selection">
ndb-optimized-node-selection
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_optimized_node_selection">
ndb_optimized_node_selection
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_pruned_scan_count">
Ndb_pruned_scan_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_pushed_queries_defined">
Ndb_pushed_queries_defined
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_pushed_queries_dropped">
Ndb_pushed_queries_dropped
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_pushed_queries_executed">
Ndb_pushed_queries_executed
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_pushed_reads">
Ndb_pushed_reads
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_read_backup">
ndb_read_backup
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_recv_thread_activation_threshold">
ndb_recv_thread_activation_threshold
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_recv_thread_cpu_mask">
ndb_recv_thread_cpu_mask
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_replica_batch_size">
ndb_replica_batch_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_replica_blob_write_batch_bytes">
ndb_replica_blob_write_batch_bytes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_replica_max_replicated_epoch">
Ndb_replica_max_replicated_epoch
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_report_thresh_binlog_epoch_slip">
ndb_report_thresh_binlog_epoch_slip
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_report_thresh_binlog_mem_usage">
ndb_report_thresh_binlog_mem_usage
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_row_checksum">
ndb_row_checksum
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_scan_count">
Ndb_scan_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_schema_dist_lock_wait_timeout">
ndb_schema_dist_lock_wait_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-schema-dist-timeout">
ndb_schema_dist_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_schema_dist_timeout">
ndb_schema_dist_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_schema_dist_upgrade_allowed">
ndb_schema_dist_upgrade_allowed
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_show_foreign_key_mock_tables">
ndb_show_foreign_key_mock_tables
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_slave_conflict_role">
ndb_slave_conflict_role
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_slave_max_replicated_epoch">
Ndb_slave_max_replicated_epoch
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_system_name">
Ndb_system_name
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_table_no_logging">
ndb_table_no_logging
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_table_temporary">
ndb_table_temporary
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-tls-search-path">
ndb_tls_search_path
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
-
<span class="emphasis">
<em>
Variable
</em>
</span>
: yes
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#statvar_Ndb_trans_hint_count_session">
Ndb_trans_hint_count_session
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-transid-mysql-connection-map">
ndb-transid-mysql-connection-map
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_use_copying_alter_table">
ndb_use_copying_alter_table
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_use_exact_count">
ndb_use_exact_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_use_transactions">
ndb_use_transactions
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_version">
ndb_version
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_version_string">
ndb_version_string
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-wait-connected">
ndb_wait_connected
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndb-wait-setup">
ndb_wait_setup
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndbcluster">
ndbcluster
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndbinfo">
ndbinfo
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndbinfo_database">
ndbinfo_database
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndbinfo_max_bytes">
ndbinfo_max_bytes
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndbinfo_max_rows">
ndbinfo_max_rows
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndbinfo_offline">
ndbinfo_offline
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndbinfo_show_hidden">
ndbinfo_show_hidden
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndbinfo_table_prefix">
ndbinfo_table_prefix
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_ndbinfo_version">
ndbinfo_version
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_net_buffer_length">
net_buffer_length
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_net_read_timeout">
net_read_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_net_retry_count">
net_retry_count
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_net_write_timeout">
net_write_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_ngram_token_size">
ngram_token_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_no-defaults">
no-defaults
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_no-monitor">
no-monitor
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Not_flushed_delayed_rows">
Not_flushed_delayed_rows
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_offline_mode">
offline_mode
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_old_alter_table">
old_alter_table
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ongoing_anonymous_gtid_violating_transaction_count">
Ongoing_anonymous_gtid_violating_transaction_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ongoing_anonymous_transaction_count">
Ongoing_anonymous_transaction_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ongoing_automatic_gtid_violating_transaction_count">
Ongoing_automatic_gtid_violating_transaction_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Open_files">
Open_files
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_open_files_limit">
open_files_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Open_streams">
Open_streams
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Open_table_definitions">
Open_table_definitions
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Open_tables">
Open_tables
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Opened_files">
Opened_files
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Opened_table_definitions">
Opened_table_definitions
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Opened_tables">
Opened_tables
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_optimizer_prune_level">
optimizer_prune_level
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_optimizer_search_depth">
optimizer_search_depth
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_optimizer_switch">
optimizer_switch
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_optimizer_trace">
optimizer_trace
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_optimizer_trace_features">
optimizer_trace_features
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_optimizer_trace_limit">
optimizer_trace_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_optimizer_trace_max_mem_size">
optimizer_trace_max_mem_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_optimizer_trace_offset">
optimizer_trace_offset
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_original_commit_timestamp">
original_commit_timestamp
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#sysvar_original_server_version">
original_server_version
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_parser_max_mem_size">
parser_max_mem_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_partial_revokes">
partial_revokes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_password_history">
password_history
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_password_require_current">
password_require_current
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_password_reuse_interval">
password_reuse_interval
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema">
performance_schema
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_accounts_lost">
Performance_schema_accounts_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_accounts_size">
performance_schema_accounts_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_cond_classes_lost">
Performance_schema_cond_classes_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_cond_instances_lost">
Performance_schema_cond_instances_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-consumer-events-stages-current">
performance-schema-consumer-events-stages-current
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-consumer-events-stages-history">
performance-schema-consumer-events-stages-history
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-consumer-events-stages-history-long">
performance-schema-consumer-events-stages-history-long
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-consumer-events-statements-cpu">
performance-schema-consumer-events-statements-cpu
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-consumer-events-statements-current">
performance-schema-consumer-events-statements-current
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-consumer-events-statements-history">
performance-schema-consumer-events-statements-history
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-consumer-events-statements-history-long">
performance-schema-consumer-events-statements-history-long
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-consumer-events-transactions-current">
performance-schema-consumer-events-transactions-current
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-consumer-events-transactions-history">
performance-schema-consumer-events-transactions-history
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-consumer-events-transactions-history-long">
performance-schema-consumer-events-transactions-history-long
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-consumer-events-waits-current">
performance-schema-consumer-events-waits-current
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-consumer-events-waits-history">
performance-schema-consumer-events-waits-history
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-consumer-events-waits-history-long">
performance-schema-consumer-events-waits-history-long
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-consumer-global-instrumentation">
performance-schema-consumer-global-instrumentation
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-consumer-statements-digest">
performance-schema-consumer-statements-digest
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-consumer-thread-instrumentation">
performance-schema-consumer-thread-instrumentation
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_digest_lost">
Performance_schema_digest_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_digests_size">
performance_schema_digests_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_error_size">
performance_schema_error_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_events_stages_history_long_size">
performance_schema_events_stages_history_long_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_events_stages_history_size">
performance_schema_events_stages_history_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_events_statements_history_long_size">
performance_schema_events_statements_history_long_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_events_statements_history_size">
performance_schema_events_statements_history_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_events_transactions_history_long_size">
performance_schema_events_transactions_history_long_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_events_transactions_history_size">
performance_schema_events_transactions_history_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_events_waits_history_long_size">
performance_schema_events_waits_history_long_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_events_waits_history_size">
performance_schema_events_waits_history_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_file_classes_lost">
Performance_schema_file_classes_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_file_handles_lost">
Performance_schema_file_handles_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_file_instances_lost">
Performance_schema_file_instances_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_hosts_lost">
Performance_schema_hosts_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_hosts_size">
performance_schema_hosts_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_index_stat_lost">
Performance_schema_index_stat_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-options.html#option_mysqld_performance-schema-instrument">
performance-schema-instrument
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_locker_lost">
Performance_schema_locker_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_cond_classes">
performance_schema_max_cond_classes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_cond_instances">
performance_schema_max_cond_instances
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_digest_length">
performance_schema_max_digest_length
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_digest_sample_age">
performance_schema_max_digest_sample_age
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_file_classes">
performance_schema_max_file_classes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_file_handles">
performance_schema_max_file_handles
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_file_instances">
performance_schema_max_file_instances
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_index_stat">
performance_schema_max_index_stat
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_memory_classes">
performance_schema_max_memory_classes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_metadata_locks">
performance_schema_max_metadata_locks
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_meter_classes">
performance_schema_max_meter_classes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_metric_classes">
performance_schema_max_metric_classes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_mutex_classes">
performance_schema_max_mutex_classes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_mutex_instances">
performance_schema_max_mutex_instances
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_prepared_statements_instances">
performance_schema_max_prepared_statements_instances
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_program_instances">
performance_schema_max_program_instances
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_rwlock_classes">
performance_schema_max_rwlock_classes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_rwlock_instances">
performance_schema_max_rwlock_instances
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_socket_classes">
performance_schema_max_socket_classes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_socket_instances">
performance_schema_max_socket_instances
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_sql_text_length">
performance_schema_max_sql_text_length
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_stage_classes">
performance_schema_max_stage_classes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_statement_classes">
performance_schema_max_statement_classes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_statement_stack">
performance_schema_max_statement_stack
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_table_handles">
performance_schema_max_table_handles
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_table_instances">
performance_schema_max_table_instances
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_table_lock_stat">
performance_schema_max_table_lock_stat
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_thread_classes">
performance_schema_max_thread_classes
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_thread_instances">
performance_schema_max_thread_instances
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_memory_classes_lost">
Performance_schema_memory_classes_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_metadata_lock_lost">
Performance_schema_metadata_lock_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_meter_lost">
Performance_schema_meter_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_metric_lost">
Performance_schema_metric_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_mutex_classes_lost">
Performance_schema_mutex_classes_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_mutex_instances_lost">
Performance_schema_mutex_instances_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_nested_statement_lost">
Performance_schema_nested_statement_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_prepared_statements_lost">
Performance_schema_prepared_statements_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_program_lost">
Performance_schema_program_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_rwlock_classes_lost">
Performance_schema_rwlock_classes_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_rwlock_instances_lost">
Performance_schema_rwlock_instances_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_session_connect_attrs_longest_seen">
Performance_schema_session_connect_attrs_longest_seen
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_session_connect_attrs_lost">
Performance_schema_session_connect_attrs_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_session_connect_attrs_size">
performance_schema_session_connect_attrs_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_setup_actors_size">
performance_schema_setup_actors_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_setup_objects_size">
performance_schema_setup_objects_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_show_processlist">
performance_schema_show_processlist
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_socket_classes_lost">
Performance_schema_socket_classes_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_socket_instances_lost">
Performance_schema_socket_instances_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_stage_classes_lost">
Performance_schema_stage_classes_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_statement_classes_lost">
Performance_schema_statement_classes_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_table_handles_lost">
Performance_schema_table_handles_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_table_instances_lost">
Performance_schema_table_instances_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_table_lock_stat_lost">
Performance_schema_table_lock_stat_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_thread_classes_lost">
Performance_schema_thread_classes_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_thread_instances_lost">
Performance_schema_thread_instances_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-status-variables.html#statvar_Performance_schema_users_lost">
Performance_schema_users_lost
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_users_size">
performance_schema_users_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_persist_only_admin_x509_subject">
persist_only_admin_x509_subject
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_persist_sensitive_variables_in_plaintext">
persist_sensitive_variables_in_plaintext
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_persisted_globals_load">
persisted_globals_load
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_pid_file">
pid_file
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_plugin_dir">
plugin_dir
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_plugin-load">
plugin-load
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_plugin-load-add">
plugin-load-add
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_plugin-xxx">
plugin-xxx
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_port">
port
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_port-open-timeout">
port-open-timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_preload_buffer_size">
preload_buffer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Prepared_stmt_count">
Prepared_stmt_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_print-defaults">
print-defaults
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_print_identified_with_as_hex">
print_identified_with_as_hex
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_profiling">
profiling
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_profiling_history_size">
profiling_history_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_protocol_compression_algorithms">
protocol_compression_algorithms
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_protocol_version">
protocol_version
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_proxy_user">
proxy_user
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_pseudo_replica_mode">
pseudo_replica_mode
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_pseudo_slave_mode">
pseudo_slave_mode
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_pseudo_thread_id">
pseudo_thread_id
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Queries">
Queries
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_query_alloc_block_size">
query_alloc_block_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_query_prealloc_size">
query_prealloc_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Questions">
Questions
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_rand_seed1">
rand_seed1
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_rand_seed2">
rand_seed2
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_range_alloc_block_size">
range_alloc_block_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_range_optimizer_max_mem_size">
range_optimizer_max_mem_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_rbr_exec_mode">
rbr_exec_mode
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_read_buffer_size">
read_buffer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_read_only">
read_only
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_read_rnd_buffer_size">
read_rnd_buffer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_regexp_stack_limit">
regexp_stack_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_regexp_time_limit">
regexp_time_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_relay_log">
relay_log
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_relay_log_basename">
relay_log_basename
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_relay_log_index">
relay_log_index
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_relay_log_purge">
relay_log_purge
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_relay_log_recovery">
relay_log_recovery
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_relay_log_space_limit">
relay_log_space_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_remove">
remove
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_replica_allow_batching">
replica_allow_batching
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replica_checkpoint_group">
replica_checkpoint_group
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replica_checkpoint_period">
replica_checkpoint_period
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replica_compressed_protocol">
replica_compressed_protocol
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replica_exec_mode">
replica_exec_mode
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replica_load_tmpdir">
replica_load_tmpdir
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replica_max_allowed_packet">
replica_max_allowed_packet
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replica_net_timeout">
replica_net_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Replica_open_temp_tables">
Replica_open_temp_tables
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replica_parallel_type">
replica_parallel_type
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replica_parallel_workers">
replica_parallel_workers
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replica_pending_jobs_size_max">
replica_pending_jobs_size_max
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replica_preserve_commit_order">
replica_preserve_commit_order
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replica_skip_errors">
replica_skip_errors
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replica_sql_verify_checksum">
replica_sql_verify_checksum
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replica_transaction_retries">
replica_transaction_retries
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replica_type_conversions">
replica_type_conversions
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#option_mysqld_replicate-do-db">
replicate-do-db
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#option_mysqld_replicate-do-table">
replicate-do-table
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#option_mysqld_replicate-ignore-db">
replicate-ignore-db
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#option_mysqld_replicate-ignore-table">
replicate-ignore-table
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#option_mysqld_replicate-rewrite-db">
replicate-rewrite-db
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#option_mysqld_replicate-same-server-id">
replicate-same-server-id
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#option_mysqld_replicate-wild-do-table">
replicate-wild-do-table
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#option_mysqld_replicate-wild-ignore-table">
replicate-wild-ignore-table
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replication_optimize_for_static_plugin_config">
replication_optimize_for_static_plugin_config
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_replication_sender_observe_commit_only">
replication_sender_observe_commit_only
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_report_host">
report_host
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_report_password">
report_password
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_report_port">
report_port
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_report_user">
report_user
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_require_row_format">
require_row_format
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_require_secure_transport">
require_secure_transport
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Resource_group_supported">
Resource_group_supported
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_restrict_fk_on_non_standard_key">
restrict_fk_on_non_standard_key
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_resultset_metadata">
resultset_metadata
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="rewriter-query-rewrite-plugin-reference.html#sysvar_rewriter_enabled">
rewriter_enabled
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="rewriter-query-rewrite-plugin-reference.html#sysvar_rewriter_enabled_for_threads_without_privilege_checks">
rewriter_enabled_for_threads_without_privilege_checks
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="rewriter-query-rewrite-plugin-reference.html#statvar_Rewriter_number_loaded_rules">
Rewriter_number_loaded_rules
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="rewriter-query-rewrite-plugin-reference.html#statvar_Rewriter_number_reloads">
Rewriter_number_reloads
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="rewriter-query-rewrite-plugin-reference.html#statvar_Rewriter_number_rewritten_queries">
Rewriter_number_rewritten_queries
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="rewriter-query-rewrite-plugin-reference.html#statvar_Rewriter_reload_error">
Rewriter_reload_error
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="rewriter-query-rewrite-plugin-reference.html#sysvar_rewriter_verbose">
rewriter_verbose
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_rpl_read_size">
rpl_read_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_master_clients">
Rpl_semi_sync_master_clients
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#sysvar_rpl_semi_sync_master_enabled">
rpl_semi_sync_master_enabled
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_master_net_avg_wait_time">
Rpl_semi_sync_master_net_avg_wait_time
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_master_net_wait_time">
Rpl_semi_sync_master_net_wait_time
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_master_net_waits">
Rpl_semi_sync_master_net_waits
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_master_no_times">
Rpl_semi_sync_master_no_times
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_master_no_tx">
Rpl_semi_sync_master_no_tx
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_master_status">
Rpl_semi_sync_master_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_master_timefunc_failures">
Rpl_semi_sync_master_timefunc_failures
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#sysvar_rpl_semi_sync_master_timeout">
rpl_semi_sync_master_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#sysvar_rpl_semi_sync_master_trace_level">
rpl_semi_sync_master_trace_level
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_master_tx_avg_wait_time">
Rpl_semi_sync_master_tx_avg_wait_time
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_master_tx_wait_time">
Rpl_semi_sync_master_tx_wait_time
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_master_tx_waits">
Rpl_semi_sync_master_tx_waits
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#sysvar_rpl_semi_sync_master_wait_for_slave_count">
rpl_semi_sync_master_wait_for_slave_count
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#sysvar_rpl_semi_sync_master_wait_no_slave">
rpl_semi_sync_master_wait_no_slave
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#sysvar_rpl_semi_sync_master_wait_point">
rpl_semi_sync_master_wait_point
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_master_wait_pos_backtraverse">
Rpl_semi_sync_master_wait_pos_backtraverse
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_master_wait_sessions">
Rpl_semi_sync_master_wait_sessions
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_master_yes_tx">
Rpl_semi_sync_master_yes_tx
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_rpl_semi_sync_replica_enabled">
rpl_semi_sync_replica_enabled
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_replica_status">
Rpl_semi_sync_replica_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_rpl_semi_sync_replica_trace_level">
rpl_semi_sync_replica_trace_level
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_rpl_semi_sync_slave_enabled">
rpl_semi_sync_slave_enabled
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_slave_status">
Rpl_semi_sync_slave_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_rpl_semi_sync_slave_trace_level">
rpl_semi_sync_slave_trace_level
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_source_clients">
Rpl_semi_sync_source_clients
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#sysvar_rpl_semi_sync_source_enabled">
rpl_semi_sync_source_enabled
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_source_net_avg_wait_time">
Rpl_semi_sync_source_net_avg_wait_time
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_source_net_wait_time">
Rpl_semi_sync_source_net_wait_time
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_source_net_waits">
Rpl_semi_sync_source_net_waits
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_source_no_times">
Rpl_semi_sync_source_no_times
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_source_no_tx">
Rpl_semi_sync_source_no_tx
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_source_status">
Rpl_semi_sync_source_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_source_timefunc_failures">
Rpl_semi_sync_source_timefunc_failures
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#sysvar_rpl_semi_sync_source_timeout">
rpl_semi_sync_source_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#sysvar_rpl_semi_sync_source_trace_level">
rpl_semi_sync_source_trace_level
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_source_tx_avg_wait_time">
Rpl_semi_sync_source_tx_avg_wait_time
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_source_tx_wait_time">
Rpl_semi_sync_source_tx_wait_time
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_source_tx_waits">
Rpl_semi_sync_source_tx_waits
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#sysvar_rpl_semi_sync_source_wait_for_replica_count">
rpl_semi_sync_source_wait_for_replica_count
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#sysvar_rpl_semi_sync_source_wait_no_replica">
rpl_semi_sync_source_wait_no_replica
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#sysvar_rpl_semi_sync_source_wait_point">
rpl_semi_sync_source_wait_point
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_source_wait_pos_backtraverse">
Rpl_semi_sync_source_wait_pos_backtraverse
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_source_wait_sessions">
Rpl_semi_sync_source_wait_sessions
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rpl_semi_sync_source_yes_tx">
Rpl_semi_sync_source_yes_tx
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_rpl_stop_replica_timeout">
rpl_stop_replica_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_rpl_stop_slave_timeout">
rpl_stop_slave_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Rsa_public_key">
Rsa_public_key
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_safe-user-create">
safe-user-create
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_schema_definition_cache">
schema_definition_cache
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_secondary_engine_cost_threshold">
secondary_engine_cost_threshold
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Secondary_engine_execution_count">
Secondary_engine_execution_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_secure_file_priv">
secure_file_priv
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Select_full_join">
Select_full_join
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Select_full_range_join">
Select_full_range_join
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_select_into_buffer_size">
select_into_buffer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_select_into_disk_sync">
select_into_disk_sync
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_select_into_disk_sync_delay">
select_into_disk_sync_delay
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Select_range">
Select_range
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Select_range_check">
Select_range_check
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Select_scan">
Select_scan
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options.html#sysvar_server_id">
server_id
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_server_id_bits">
server_id_bits
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options.html#sysvar_server_uuid">
server_uuid
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_session_track_gtids">
session_track_gtids
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_session_track_schema">
session_track_schema
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_session_track_state_change">
session_track_state_change
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_session_track_system_variables">
session_track_system_variables
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_session_track_transaction_info">
session_track_transaction_info
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_set_operations_buffer_size">
set_operations_buffer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_sha256_password_auto_generate_rsa_keys">
sha256_password_auto_generate_rsa_keys
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_sha256_password_private_key_path">
sha256_password_private_key_path
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_sha256_password_proxy_users">
sha256_password_proxy_users
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_sha256_password_public_key_path">
sha256_password_public_key_path
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_shared_memory">
shared_memory
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_shared_memory_base_name">
shared_memory_base_name
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_show_create_table_skip_secondary_engine">
show_create_table_skip_secondary_engine
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_show_create_table_verbosity">
show_create_table_verbosity
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_show_gipk_in_create_table_and_information_schema">
show_gipk_in_create_table_and_information_schema
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#option_mysqld_show-replica-auth-info">
show-replica-auth-info
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-source.html#option_mysqld_show-slave-auth-info">
show-slave-auth-info
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_skip_external_locking">
skip_external_locking
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_skip-grant-tables">
skip-grant-tables
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_skip_name_resolve">
skip_name_resolve
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_skip-ndbcluster">
skip-ndbcluster
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_skip_networking">
skip_networking
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_skip-new">
skip-new
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#option_mysqld_skip-replica-start">
skip_replica_start
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_skip-show-database">
skip_show_database
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#option_mysqld_skip-slave-start">
skip_slave_start
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_skip-stack-trace">
skip-stack-trace
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_slave_allow_batching">
slave_allow_batching
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_slave_checkpoint_group">
slave_checkpoint_group
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_slave_checkpoint_period">
slave_checkpoint_period
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_slave_compressed_protocol">
slave_compressed_protocol
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_slave_exec_mode">
slave_exec_mode
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_slave_load_tmpdir">
slave_load_tmpdir
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_slave_max_allowed_packet">
slave_max_allowed_packet
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_slave_net_timeout">
slave_net_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Slave_open_temp_tables">
Slave_open_temp_tables
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_slave_parallel_type">
slave_parallel_type
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_slave_parallel_workers">
slave_parallel_workers
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_slave_pending_jobs_size_max">
slave_pending_jobs_size_max
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_slave_preserve_commit_order">
slave_preserve_commit_order
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Slave_rows_last_search_algorithm_used">
Slave_rows_last_search_algorithm_used
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#option_mysqld_slave-skip-errors">
slave_skip_errors
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#option_mysqld_slave-sql-verify-checksum">
slave-sql-verify-checksum
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_slave_sql_verify_checksum">
slave_sql_verify_checksum
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_slave_transaction_retries">
slave_transaction_retries
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_slave_type_conversions">
slave_type_conversions
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Slow_launch_threads">
Slow_launch_threads
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_slow_launch_time">
slow_launch_time
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Slow_queries">
Slow_queries
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_slow_query_log">
slow_query_log
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_slow_query_log_file">
slow_query_log_file
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_slow-start-timeout">
slow-start-timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_socket">
socket
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_sort_buffer_size">
sort_buffer_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Sort_merge_passes">
Sort_merge_passes
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Sort_range">
Sort_range
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Sort_rows">
Sort_rows
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Sort_scan">
Sort_scan
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_source_verify_checksum">
source_verify_checksum
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#option_mysqld_sporadic-binlog-dump-fail">
sporadic-binlog-dump-fail
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_sql_auto_is_null">
sql_auto_is_null
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_sql_big_selects">
sql_big_selects
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_sql_buffer_result">
sql_buffer_result
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_sql_generate_invisible_primary_key">
sql_generate_invisible_primary_key
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_sql_log_bin">
sql_log_bin
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_sql_log_off">
sql_log_off
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_sql-mode">
sql_mode
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_sql_notes">
sql_notes
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_sql_quote_show_create">
sql_quote_show_create
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_sql_replica_skip_counter">
sql_replica_skip_counter
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_sql_require_primary_key">
sql_require_primary_key
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_sql_safe_updates">
sql_safe_updates
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_sql_select_limit">
sql_select_limit
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_sql_slave_skip_counter">
sql_slave_skip_counter
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_sql_warnings">
sql_warnings
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_accept_renegotiates">
Ssl_accept_renegotiates
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_accepts">
Ssl_accepts
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_ssl_ca">
ssl_ca
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_callback_cache_hits">
Ssl_callback_cache_hits
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_ssl_capath">
ssl_capath
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_ssl_cert">
ssl_cert
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_cipher">
Ssl_cipher
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_ssl_cipher">
ssl_cipher
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_cipher_list">
Ssl_cipher_list
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_client_connects">
Ssl_client_connects
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_connect_renegotiates">
Ssl_connect_renegotiates
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_ssl_crl">
ssl_crl
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_ssl_crlpath">
ssl_crlpath
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_ctx_verify_depth">
Ssl_ctx_verify_depth
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_ctx_verify_mode">
Ssl_ctx_verify_mode
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_default_timeout">
Ssl_default_timeout
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_finished_accepts">
Ssl_finished_accepts
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_finished_connects">
Ssl_finished_connects
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_ssl_fips_mode">
ssl_fips_mode
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_ssl_key">
ssl_key
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_server_not_after">
Ssl_server_not_after
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_server_not_before">
Ssl_server_not_before
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_session_cache_hits">
Ssl_session_cache_hits
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_session_cache_misses">
Ssl_session_cache_misses
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_session_cache_mode">
Ssl_session_cache_mode
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_ssl_session_cache_mode">
ssl_session_cache_mode
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_session_cache_overflows">
Ssl_session_cache_overflows
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_session_cache_size">
Ssl_session_cache_size
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_session_cache_timeout">
Ssl_session_cache_timeout
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_ssl_session_cache_timeout">
ssl_session_cache_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_session_cache_timeouts">
Ssl_session_cache_timeouts
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_sessions_reused">
Ssl_sessions_reused
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_used_session_cache_entries">
Ssl_used_session_cache_entries
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_verify_depth">
Ssl_verify_depth
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_verify_mode">
Ssl_verify_mode
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Ssl_version">
Ssl_version
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_standalone">
standalone
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_statement_id">
statement_id
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_stored_program_cache">
stored_program_cache
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_stored_program_definition_cache">
stored_program_definition_cache
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_super-large-pages">
super-large-pages
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_super_read_only">
super_read_only
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_symbolic-links">
symbolic-links
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-binary-log.html#sysvar_sync_binlog">
sync_binlog
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_sync_master_info">
sync_master_info
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_sync_relay_log">
sync_relay_log
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_sync_relay_log_info">
sync_relay_log_info
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_sync_source_info">
sync_source_info
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_sysdate-is-now">
sysdate-is-now
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_syseventlog.facility">
syseventlog.facility
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_syseventlog.include_pid">
syseventlog.include_pid
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_syseventlog.tag">
syseventlog.tag
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_system_time_zone">
system_time_zone
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_table_definition_cache">
table_definition_cache
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_table_encryption_privilege_check">
table_encryption_privilege_check
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Table_locks_immediate">
Table_locks_immediate
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Table_locks_waited">
Table_locks_waited
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_table_open_cache">
table_open_cache
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Table_open_cache_hits">
Table_open_cache_hits
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_table_open_cache_instances">
table_open_cache_instances
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Table_open_cache_misses">
Table_open_cache_misses
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Table_open_cache_overflows">
Table_open_cache_overflows
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_tablespace_definition_cache">
tablespace_definition_cache
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_tc-heuristic-recover">
tc-heuristic-recover
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Tc_log_max_pages_used">
Tc_log_max_pages_used
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Tc_log_page_size">
Tc_log_page_size
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Tc_log_page_waits">
Tc_log_page_waits
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Telemetry_metrics_supported">
Telemetry_metrics_supported
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Telemetry_traces_supported">
Telemetry_traces_supported
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_telemetry.live_sessions">
telemetry.live_sessions
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.metrics_reader_frequency_1">
telemetry.metrics_reader_frequency_1
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.metrics_reader_frequency_2">
telemetry.metrics_reader_frequency_2
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.metrics_reader_frequency_3">
telemetry.metrics_reader_frequency_3
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_bsp_max_export_batch_size">
telemetry.otel_bsp_max_export_batch_size
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_bsp_max_queue_size">
telemetry.otel_bsp_max_queue_size
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_bsp_schedule_delay">
telemetry.otel_bsp_schedule_delay
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_certificates">
telemetry.otel_exporter_otlp_metrics_certificates
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_cipher">
telemetry.otel_exporter_otlp_metrics_cipher
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_cipher_suite">
telemetry.otel_exporter_otlp_metrics_cipher_suite
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_client_certificates">
telemetry.otel_exporter_otlp_metrics_client_certificates
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_client_key">
telemetry.otel_exporter_otlp_metrics_client_key
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_compression">
telemetry.otel_exporter_otlp_metrics_compression
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_endpoint">
telemetry.otel_exporter_otlp_metrics_endpoint
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_headers">
telemetry.otel_exporter_otlp_metrics_headers
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_min_tls">
telemetry.otel_exporter_otlp_metrics_max_tls
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_min_tls">
telemetry.otel_exporter_otlp_metrics_min_tls
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_protocol">
telemetry.otel_exporter_otlp_metrics_protocol
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_timeout">
telemetry.otel_exporter_otlp_metrics_timeout
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_exporter_otlp_traces_certificates">
telemetry.otel_exporter_otlp_traces_certificates
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_exporter_otlp_traces_cipher">
telemetry.otel_exporter_otlp_traces_cipher
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_exporter_otlp_traces_cipher_suite">
telemetry.otel_exporter_otlp_traces_cipher_suite
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_exporter_otlp_traces_client_certificates">
telemetry.otel_exporter_otlp_traces_client_certificates
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_exporter_otlp_traces_client_key">
telemetry.otel_exporter_otlp_traces_client_key
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_exporter_otlp_traces_compression">
telemetry.otel_exporter_otlp_traces_compression
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_exporter_otlp_traces_endpoint">
telemetry.otel_exporter_otlp_traces_endpoint
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_exporter_otlp_traces_headers">
telemetry.otel_exporter_otlp_traces_headers
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_exporter_otlp_traces_max_tls">
telemetry.otel_exporter_otlp_traces_max_tls
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_exporter_otlp_traces_min_tls">
telemetry.otel_exporter_otlp_traces_min_tls
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_exporter_otlp_traces_protocol">
telemetry.otel_exporter_otlp_traces_protocol
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_exporter_otlp_traces_timeout">
telemetry.otel_exporter_otlp_traces_timeout
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_log_level">
telemetry.otel_log_level
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.otel_resource_attributes">
telemetry.otel_resource_attributes
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.query_text_enabled">
telemetry.query_text_enabled
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="telemetry-trace-configuration.html#sysvar_telemetry.trace_enabled">
telemetry.trace_enabled
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_temptable_max_mmap">
temptable_max_mmap
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_temptable_max_ram">
temptable_max_ram
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_temptable_use_mmap">
temptable_use_mmap
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="replication-options-replica.html#sysvar_terminology_use_previous">
terminology_use_previous
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_thread_cache_size">
thread_cache_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_thread_handling">
thread_handling
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_thread_pool_algorithm">
thread_pool_algorithm
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_thread_pool_dedicated_listeners">
thread_pool_dedicated_listeners
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_thread_pool_high_priority_connection">
thread_pool_high_priority_connection
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_thread_pool_longrun_trx_limit">
thread_pool_longrun_trx_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_thread_pool_max_active_query_threads">
thread_pool_max_active_query_threads
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_thread_pool_max_transactions_limit">
thread_pool_max_transactions_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_thread_pool_max_unused_threads">
thread_pool_max_unused_threads
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_thread_pool_prio_kickup_timer">
thread_pool_prio_kickup_timer
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_thread_pool_query_threads_per_group">
thread_pool_query_threads_per_group
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_thread_pool_size">
thread_pool_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_thread_pool_stall_limit">
thread_pool_stall_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_thread_pool_transaction_delay">
thread_pool_transaction_delay
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_thread_stack">
thread_stack
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Threads_cached">
Threads_cached
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Threads_connected">
Threads_connected
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Threads_created">
Threads_created
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Threads_running">
Threads_running
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_time_zone">
time_zone
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_timestamp">
timestamp
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_tls_certificates_enforced_validation">
tls_certificates_enforced_validation
</a>
</th>
<td>
Yes
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_tls_ciphersuites">
tls_ciphersuites
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Tls_library_version">
Tls_library_version
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Tls_sni_server_name">
Tls_sni_server_name
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_tls_version">
tls_version
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_tmp_table_size">
tmp_table_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_tmpdir">
tmpdir
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_transaction_alloc_block_size">
transaction_alloc_block_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="mysql-cluster-options-variables.html#sysvar_transaction_allow_batching">
transaction_allow_batching
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_transaction-isolation">
transaction_isolation
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_transaction_prealloc_size">
transaction_prealloc_size
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_transaction-read-only">
transaction_read_only
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_unique_checks">
unique_checks
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_updatable_views_with_limit">
updatable_views_with_limit
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_upgrade">
upgrade
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Uptime">
Uptime
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-status-variables.html#statvar_Uptime_since_flush_status">
Uptime_since_flush_status
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_use_secondary_engine">
use_secondary_engine
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_user">
user
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_validate-config">
validate-config
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#option_mysqld_validate-password">
validate-password
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_check_user_name">
validate_password_check_user_name
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_dictionary_file">
validate_password_dictionary_file
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#statvar_validate_password_dictionary_file_last_parsed">
validate_password_dictionary_file_last_parsed
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#statvar_validate_password_dictionary_file_words_count">
validate_password_dictionary_file_words_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_length">
validate_password_length
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_mixed_case_count">
validate_password_mixed_case_count
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_number_count">
validate_password_number_count
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_policy">
validate_password_policy
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_special_char_count">
validate_password_special_char_count
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.changed_characters_percentage">
validate_password.changed_characters_percentage
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.check_user_name">
validate_password.check_user_name
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.dictionary_file">
validate_password.dictionary_file
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#statvar_validate_password.dictionary_file_last_parsed">
validate_password.dictionary_file_last_parsed
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#statvar_validate_password.dictionary_file_words_count">
validate_password.dictionary_file_words_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.length">
validate_password.length
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.mixed_case_count">
validate_password.mixed_case_count
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.number_count">
validate_password.number_count
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.policy">
validate_password.policy
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.special_char_count">
validate_password.special_char_count
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_validate-user-plugins">
validate-user-plugins
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-options.html#option_mysqld_verbose">
verbose
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_version">
version
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_version_comment">
version_comment
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_version_compile_machine">
version_compile_machine
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_version_compile_os">
version_compile_os
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_version_compile_zlib">
version_compile_zlib
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Global
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="version-tokens-reference.html#sysvar_version_tokens_session">
version_tokens_session
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="version-tokens-reference.html#sysvar_version_tokens_session_number">
version_tokens_session_number
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_wait_timeout">
wait_timeout
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_warning_count">
warning_count
</a>
</th>
<td>
</td>
<td>
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Session
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_windowing_use_high_precision">
windowing_use_high_precision
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
<tr>
<th scope="row">
<a class="link" href="server-system-variables.html#sysvar_xa_detach_on_prepare">
xa_detach_on_prepare
</a>
</th>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
Yes
</td>
<td>
</td>
<td>
Both
</td>
<td>
Yes
</td>
</tr>
</tbody>
</table>
</div>
<div class="table-contents">
<table cellpadding="0" cellspacing="0" style="position: fixed; top: 0px; display: none; left: 401px; width: 808px;">
<thead>
<tr>
<th scope="col" style="width: 472.031px;">
Name
</th>
<th scope="col" style="width: 43.6875px;">
Cmd-Line
</th>
<th scope="col" style="width: 56.0938px;">
Option File
</th>
<th scope="col" style="width: 58.6406px;">
System Var
</th>
<th scope="col" style="width: 52.2812px;">
Status Var
</th>
<th scope="col" style="width: 54.8594px;">
Var Scope
</th>
<th scope="col" style="width: 69.2969px;">
Dynamic
</th>
</tr>
</thead>
</table>
</div>
</div>
<br class="table-break"/>
<p>
<span class="bold">
<strong>
Notes:
</strong>
</span>
</p>
<p>
1. This option is dynamic, but should be set only by server. You should not set this variable manually.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/performance-schema.html | <div id="docs-body">
<div class="chapter">
<div class="titlepage">
<div>
<div>
<h1 class="title">
<a name="performance-schema">
</a>
Chapter 29 MySQL Performance Schema
</h1>
</div>
</div>
</div>
<div class="toc">
<p>
<b>
Table of Contents
</b>
</p>
<dl class="toc">
<dt>
<span class="section">
<a href="performance-schema-quick-start.html">
29.1 Performance Schema Quick Start
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-build-configuration.html">
29.2 Performance Schema Build Configuration
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-startup-configuration.html">
29.3 Performance Schema Startup Configuration
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-runtime-configuration.html">
29.4 Performance Schema Runtime Configuration
</a>
</span>
</dt>
<dd>
<dl>
<dt>
<span class="section">
<a href="performance-schema-timing.html">
29.4.1 Performance Schema Event Timing
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-filtering.html">
29.4.2 Performance Schema Event Filtering
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-pre-filtering.html">
29.4.3 Event Pre-Filtering
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-instrument-filtering.html">
29.4.4 Pre-Filtering by Instrument
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-object-filtering.html">
29.4.5 Pre-Filtering by Object
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-thread-filtering.html">
29.4.6 Pre-Filtering by Thread
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-consumer-filtering.html">
29.4.7 Pre-Filtering by Consumer
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-consumer-configurations.html">
29.4.8 Example Consumer Configurations
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-filtering-names.html">
29.4.9 Naming Instruments or Consumers for Filtering Operations
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-instrumentation-checking.html">
29.4.10 Determining What Is Instrumented
</a>
</span>
</dt>
</dl>
</dd>
<dt>
<span class="section">
<a href="performance-schema-queries.html">
29.5 Performance Schema Queries
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-instrument-naming.html">
29.6 Performance Schema Instrument Naming Conventions
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-status-monitoring.html">
29.7 Performance Schema Status Monitoring
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-atom-molecule-events.html">
29.8 Performance Schema Atom and Molecule Events
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-event-tables.html">
29.9 Performance Schema Tables for Current and Historical Events
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-statement-digests.html">
29.10 Performance Schema Statement Digests and Sampling
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-table-characteristics.html">
29.11 Performance Schema General Table Characteristics
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-table-descriptions.html">
29.12 Performance Schema Table Descriptions
</a>
</span>
</dt>
<dd>
<dl>
<dt>
<span class="section">
<a href="performance-schema-table-reference.html">
29.12.1 Performance Schema Table Reference
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-setup-tables.html">
29.12.2 Performance Schema Setup Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-instance-tables.html">
29.12.3 Performance Schema Instance Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-wait-tables.html">
29.12.4 Performance Schema Wait Event Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-stage-tables.html">
29.12.5 Performance Schema Stage Event Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-statement-tables.html">
29.12.6 Performance Schema Statement Event Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-transaction-tables.html">
29.12.7 Performance Schema Transaction Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-connection-tables.html">
29.12.8 Performance Schema Connection Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-connection-attribute-tables.html">
29.12.9 Performance Schema Connection Attribute Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-user-variable-tables.html">
29.12.10 Performance Schema User-Defined Variable Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-replication-tables.html">
29.12.11 Performance Schema Replication Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-ndb-cluster-tables.html">
29.12.12 Performance Schema NDB Cluster Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-lock-tables.html">
29.12.13 Performance Schema Lock Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-system-variable-tables.html">
29.12.14 Performance Schema System Variable Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-status-variable-tables.html">
29.12.15 Performance Schema Status Variable Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-thread-pool-tables.html">
29.12.16 Performance Schema Thread Pool Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-firewall-tables.html">
29.12.17 Performance Schema Firewall Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-keyring-tables.html">
29.12.18 Performance Schema Keyring Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-clone-tables.html">
29.12.19 Performance Schema Clone Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-summary-tables.html">
29.12.20 Performance Schema Summary Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-telemetry-tables.html">
29.12.21 Performance Schema Telemetry Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-miscellaneous-tables.html">
29.12.22 Performance Schema Miscellaneous Tables
</a>
</span>
</dt>
</dl>
</dd>
<dt>
<span class="section">
<a href="performance-schema-option-variable-reference.html">
29.13 Performance Schema Option and Variable Reference
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-options.html">
29.14 Performance Schema Command Options
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-system-variables.html">
29.15 Performance Schema System Variables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-status-variables.html">
29.16 Performance Schema Status Variables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-memory-model.html">
29.17 The Performance Schema Memory-Allocation Model
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-and-plugins.html">
29.18 Performance Schema and Plugins
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-examples.html">
29.19 Using the Performance Schema to Diagnose Problems
</a>
</span>
</dt>
<dd>
<dl>
<dt>
<span class="section">
<a href="performance-schema-query-profiling.html">
29.19.1 Query Profiling Using Performance Schema
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="performance-schema-obtaining-parent-events.html">
29.19.2 Obtaining Parent Event Information
</a>
</span>
</dt>
</dl>
</dd>
<dt>
<span class="section">
<a href="performance-schema-restrictions.html">
29.20 Restrictions on Performance Schema
</a>
</span>
</dt>
</dl>
</div>
<a class="indexterm" name="idm46045075873728">
</a>
<a class="indexterm" name="idm46045075872688">
</a>
<a class="indexterm" name="idm46045075871600">
</a>
<a class="indexterm" name="idm46045075870112">
</a>
<p>
The MySQL Performance Schema is a feature for monitoring MySQL
Server execution at a low level. The Performance Schema has these
characteristics:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
The Performance Schema provides a way to inspect internal
execution of the server at runtime. It is implemented using the
<a class="link" href="performance-schema.html" title="Chapter 29 MySQL Performance Schema">
<code class="literal">
PERFORMANCE_SCHEMA
</code>
</a>
storage engine
and the
<code class="literal">
performance_schema
</code>
database. The
Performance Schema focuses primarily on performance data. This
differs from
<code class="literal">
INFORMATION_SCHEMA
</code>
, which serves
for inspection of metadata.
</p>
</li>
<li class="listitem">
<p>
The Performance Schema monitors server events. An
<span class="quote">
“
<span class="quote">
event
</span>
”
</span>
is anything the server does that takes time
and has been instrumented so that timing information can be
collected. In general, an event could be a function call, a wait
for the operating system, a stage of an SQL statement execution
such as parsing or sorting, or an entire statement or group of
statements. Event collection provides access to information
about synchronization calls (such as for mutexes) file and table
I/O, table locks, and so forth for the server and for several
storage engines.
</p>
</li>
<li class="listitem">
<p>
Performance Schema events are distinct from events written to
the server's binary log (which describe data modifications) and
Event Scheduler events (which are a type of stored program).
</p>
</li>
<li class="listitem">
<p>
Performance Schema events are specific to a given instance of
the MySQL Server. Performance Schema tables are considered local
to the server, and changes to them are not replicated or written
to the binary log.
</p>
</li>
<li class="listitem">
<p>
Current events are available, as well as event histories and
summaries. This enables you to determine how many times
instrumented activities were performed and how much time they
took. Event information is available to show the activities of
specific threads, or activity associated with particular objects
such as a mutex or file.
</p>
</li>
<li class="listitem">
<p>
The
<a class="link" href="performance-schema.html" title="Chapter 29 MySQL Performance Schema">
<code class="literal">
PERFORMANCE_SCHEMA
</code>
</a>
storage
engine collects event data using
<span class="quote">
“
<span class="quote">
instrumentation
points
</span>
”
</span>
in server source code.
</p>
</li>
<li class="listitem">
<p>
Collected events are stored in tables in the
<code class="literal">
performance_schema
</code>
database. These tables can
be queried using
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
statements like other tables.
</p>
</li>
<li class="listitem">
<p>
Performance Schema configuration can be modified dynamically by
updating tables in the
<code class="literal">
performance_schema
</code>
database through SQL statements. Configuration changes affect
data collection immediately.
</p>
</li>
<li class="listitem">
<p>
Tables in the Performance Schema are in-memory tables that use
no persistent on-disk storage. The contents are repopulated
beginning at server startup and discarded at server shutdown.
</p>
</li>
<li class="listitem">
<p>
Monitoring is available on all platforms supported by MySQL.
</p>
<p>
Some limitations might apply: The types of timers might vary per
platform. Instruments that apply to storage engines might not be
implemented for all storage engines. Instrumentation of each
third-party engine is the responsibility of the engine
maintainer. See also
<a class="xref" href="performance-schema-restrictions.html" title="29.20 Restrictions on Performance Schema">
Section 29.20, “Restrictions on Performance Schema”
</a>
.
</p>
</li>
<li class="listitem">
<p>
Data collection is implemented by modifying the server source
code to add instrumentation. There are no separate threads
associated with the Performance Schema, unlike other features
such as replication or the Event Scheduler.
</p>
</li>
</ul>
</div>
<p>
The Performance Schema is intended to provide access to useful
information about server execution while having minimal impact on
server performance. The implementation follows these design goals:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Activating the Performance Schema causes no changes in server
behavior. For example, it does not cause thread scheduling to
change, and it does not cause query execution plans (as shown by
<a class="link" href="explain.html" title="15.8.2 EXPLAIN Statement">
<code class="literal">
EXPLAIN
</code>
</a>
) to change.
</p>
</li>
<li class="listitem">
<p>
Server monitoring occurs continuously and unobtrusively with
very little overhead. Activating the Performance Schema does not
make the server unusable.
</p>
</li>
<li class="listitem">
<p>
The parser is unchanged. There are no new keywords or
statements.
</p>
</li>
<li class="listitem">
<p>
Execution of server code proceeds normally even if the
Performance Schema fails internally.
</p>
</li>
<li class="listitem">
<p>
When there is a choice between performing processing during
event collection initially or during event retrieval later,
priority is given to making collection faster. This is because
collection is ongoing whereas retrieval is on demand and might
never happen at all.
</p>
</li>
<li class="listitem">
<p>
Most Performance Schema tables have indexes, which gives the
optimizer access to execution plans other than full table scans.
For more information, see
<a class="xref" href="performance-schema-optimization.html" title="10.2.4 Optimizing Performance Schema Queries">
Section 10.2.4, “Optimizing Performance Schema Queries”
</a>
.
</p>
</li>
<li class="listitem">
<p>
It is easy to add new instrumentation points.
</p>
</li>
<li class="listitem">
<p>
Instrumentation is versioned. If the instrumentation
implementation changes, previously instrumented code continues
to work. This benefits developers of third-party plugins because
it is not necessary to upgrade each plugin to stay synchronized
with the latest Performance Schema changes.
</p>
</li>
</ul>
</div>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
<a class="indexterm" name="idm46045075836256">
</a>
The MySQL
<code class="literal">
sys
</code>
schema is a set of objects that
provides convenient access to data collected by the Performance
Schema. The
<code class="literal">
sys
</code>
schema is installed by default.
For usage instructions, see
<a class="xref" href="sys-schema.html" title="Chapter 30 MySQL sys Schema">
Chapter 30,
<i>
MySQL sys Schema
</i>
</a>
.
</p>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-firewall-group-allowlist-table.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="performance-schema-firewall-group-allowlist-table">
</a>
29.12.17.2 The firewall_group_allowlist Table
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045069555056">
</a>
<a class="indexterm" name="idm46045069553552">
</a>
<p>
The
<a class="link" href="performance-schema-firewall-group-allowlist-table.html" title="29.12.17.2 The firewall_group_allowlist Table">
<code class="literal">
firewall_group_allowlist
</code>
</a>
table provides a view into the in-memory data cache for
MySQL Enterprise Firewall. It lists allowlist rules of registered firewall group
profiles. It is used in conjunction with the
<code class="literal">
mysql.firewall_group_allowlist
</code>
system table
that provides persistent storage of firewall data; see
<a class="xref" href="firewall-reference.html#firewall-tables" title="MySQL Enterprise Firewall Tables">
MySQL Enterprise Firewall Tables
</a>
.
</p>
<p>
The
<a class="link" href="performance-schema-firewall-group-allowlist-table.html" title="29.12.17.2 The firewall_group_allowlist Table">
<code class="literal">
firewall_group_allowlist
</code>
</a>
table has these columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
NAME
</code>
</p>
<p>
The group profile name.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
RULE
</code>
</p>
<p>
A normalized statement indicating an acceptable statement
pattern for the profile. A profile allowlist is the union
of its rules.
</p>
</li>
</ul>
</div>
<p>
The
<a class="link" href="performance-schema-firewall-group-allowlist-table.html" title="29.12.17.2 The firewall_group_allowlist Table">
<code class="literal">
firewall_group_allowlist
</code>
</a>
table has no indexes.
</p>
<p>
<a class="link" href="truncate-table.html" title="15.1.37 TRUNCATE TABLE Statement">
<code class="literal">
TRUNCATE TABLE
</code>
</a>
is not permitted
for the
<a class="link" href="performance-schema-firewall-group-allowlist-table.html" title="29.12.17.2 The firewall_group_allowlist Table">
<code class="literal">
firewall_group_allowlist
</code>
</a>
table.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-tcp-definition-direct.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="mysql-cluster-tcp-definition-direct">
</a>
25.4.3.11 NDB Cluster TCP/IP Connections Using Direct Connections
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045109120800">
</a>
<a class="indexterm" name="idm46045109119312">
</a>
<a class="indexterm" name="idm46045109117408">
</a>
<p>
Setting up a cluster using direct connections between data nodes
requires specifying explicitly the crossover IP addresses of the
data nodes so connected in the
<code class="literal">
[tcp]
</code>
section
of the cluster
<code class="filename">
config.ini
</code>
file.
</p>
<p>
In the following example, we envision a cluster with at least
four hosts, one each for a management server, an SQL node, and
two data nodes. The cluster as a whole resides on the
<code class="literal">
172.23.72.*
</code>
subnet of a LAN. In addition to
the usual network connections, the two data nodes are connected
directly using a standard crossover cable, and communicate with
one another directly using IP addresses in the
<code class="literal">
1.1.0.*
</code>
address range as shown:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-ini"><div class="docs-select-all right" id="sa56285852"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-ini"><span class="token comment" spellcheck="true"># Management Server</span>
<span class="token selector">[ndb_mgmd]</span>
<span class="token constant">Id</span><span class="token attr-value"><span class="token punctuation">=</span>1</span>
<span class="token constant">HostName</span><span class="token attr-value"><span class="token punctuation">=</span>172.23.72.20</span>
<span class="token comment" spellcheck="true"># SQL Node</span>
<span class="token selector">[mysqld]</span>
<span class="token constant">Id</span><span class="token attr-value"><span class="token punctuation">=</span>2</span>
<span class="token constant">HostName</span><span class="token attr-value"><span class="token punctuation">=</span>172.23.72.21</span>
<span class="token comment" spellcheck="true"># Data Nodes</span>
<span class="token selector">[ndbd]</span>
<span class="token constant">Id</span><span class="token attr-value"><span class="token punctuation">=</span>3</span>
<span class="token constant">HostName</span><span class="token attr-value"><span class="token punctuation">=</span>172.23.72.22</span>
<span class="token selector">[ndbd]</span>
<span class="token constant">Id</span><span class="token attr-value"><span class="token punctuation">=</span>4</span>
<span class="token constant">HostName</span><span class="token attr-value"><span class="token punctuation">=</span>172.23.72.23</span>
<span class="token comment" spellcheck="true"># TCP/IP Connections</span>
<span class="token selector">[tcp]</span>
<span class="token constant">NodeId1</span><span class="token attr-value"><span class="token punctuation">=</span>3</span>
<span class="token constant">NodeId2</span><span class="token attr-value"><span class="token punctuation">=</span>4</span>
<span class="token constant">HostName1</span><span class="token attr-value"><span class="token punctuation">=</span>1.1.0.1</span>
<span class="token constant">HostName2</span><span class="token attr-value"><span class="token punctuation">=</span>1.1.0.2</span></code></pre>
</div>
<p>
The
<a class="link" href="mysql-cluster-tcp-definition.html#ndbparam-tcp-hostname1">
<code class="literal">
HostName1
</code>
</a>
and
<a class="link" href="mysql-cluster-tcp-definition.html#ndbparam-tcp-hostname2">
<code class="literal">
HostName2
</code>
</a>
parameters are
used only when specifying direct connections.
</p>
<p>
The use of direct TCP connections between data nodes can improve
the cluster's overall efficiency by enabling the data nodes to
bypass an Ethernet device such as a switch, hub, or router, thus
cutting down on the cluster's latency.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
To take the best advantage of direct connections in this
fashion with more than two data nodes, you must have a direct
connection between each data node and every other data node in
the same node group.
</p>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/show-status.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="show-status">
</a>
15.7.7.37 SHOW STATUS Statement
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045169335088">
</a>
<a class="indexterm" name="idm46045169334016">
</a>
<a class="indexterm" name="idm46045169332944">
</a>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa86133045"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SHOW</span> <span class="token punctuation">[</span><span class="token keyword">GLOBAL</span> <span class="token operator">|</span> <span class="token keyword">SESSION</span><span class="token punctuation">]</span> <span class="token keyword">STATUS</span>
<span class="token punctuation">[</span><span class="token operator">LIKE</span> <span class="token string">'<em class="replaceable">pattern</em>'</span> <span class="token operator">|</span> <span class="token keyword">WHERE</span> <em class="replaceable">expr</em><span class="token punctuation">]</span></code></pre>
</div>
<a class="indexterm" name="idm46045169327584">
</a>
<p>
<a class="link" href="show-status.html" title="15.7.7.37 SHOW STATUS Statement">
<code class="literal">
SHOW STATUS
</code>
</a>
provides server
status information (see
<a class="xref" href="server-status-variables.html" title="7.1.10 Server Status Variables">
Section 7.1.10, “Server Status Variables”
</a>
). This statement does
not require any privilege. It requires only the ability to
connect to the server.
</p>
<p>
Status variable information is also available from these
sources:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Performance Schema tables. See
<a class="xref" href="performance-schema-status-variable-tables.html" title="29.12.15 Performance Schema Status Variable Tables">
Section 29.12.15, “Performance Schema Status Variable Tables”
</a>
.
</p>
</li>
<li class="listitem">
<p>
The
<a class="link" href="mysqladmin.html" title="6.5.2 mysqladmin — A MySQL Server Administration Program">
<span class="command">
<strong>
mysqladmin extended-status
</strong>
</span>
</a>
command.
See
<a class="xref" href="mysqladmin.html" title="6.5.2 mysqladmin — A MySQL Server Administration Program">
Section 6.5.2, “mysqladmin — A MySQL Server Administration Program”
</a>
.
</p>
</li>
</ul>
</div>
<p>
For
<a class="link" href="show-status.html" title="15.7.7.37 SHOW STATUS Statement">
<code class="literal">
SHOW STATUS
</code>
</a>
, a
<a class="link" href="string-comparison-functions.html#operator_like">
<code class="literal">
LIKE
</code>
</a>
clause, if present, indicates
which variable names to match. A
<code class="literal">
WHERE
</code>
clause
can be given to select rows using more general conditions, as
discussed in
<a class="xref" href="extended-show.html" title="28.8 Extensions to SHOW Statements">
Section 28.8, “Extensions to SHOW Statements”
</a>
.
</p>
<p>
<a class="link" href="show-status.html" title="15.7.7.37 SHOW STATUS Statement">
<code class="literal">
SHOW STATUS
</code>
</a>
accepts an optional
<code class="literal">
GLOBAL
</code>
or
<code class="literal">
SESSION
</code>
variable
scope modifier:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
With a
<code class="literal">
GLOBAL
</code>
modifier, the statement
displays the global status values. A global status variable
may represent status for some aspect of the server itself
(for example,
<code class="literal">
Aborted_connects
</code>
), or the
aggregated status over all connections to MySQL (for
example,
<code class="literal">
Bytes_received
</code>
and
<code class="literal">
Bytes_sent
</code>
). If a variable has no global
value, the session value is displayed.
</p>
</li>
<li class="listitem">
<p>
With a
<code class="literal">
SESSION
</code>
modifier, the statement
displays the status variable values for the current
connection. If a variable has no session value, the global
value is displayed.
<code class="literal">
LOCAL
</code>
is a synonym
for
<code class="literal">
SESSION
</code>
.
</p>
</li>
<li class="listitem">
<p>
If no modifier is present, the default is
<code class="literal">
SESSION
</code>
.
</p>
</li>
</ul>
</div>
<p>
The scope for each status variable is listed at
<a class="xref" href="server-status-variables.html" title="7.1.10 Server Status Variables">
Section 7.1.10, “Server Status Variables”
</a>
.
</p>
<p>
Each invocation of the
<a class="link" href="show-status.html" title="15.7.7.37 SHOW STATUS Statement">
<code class="literal">
SHOW
STATUS
</code>
</a>
statement uses an internal temporary table and
increments the global
<a class="link" href="server-status-variables.html#statvar_Created_tmp_tables">
<code class="literal">
Created_tmp_tables
</code>
</a>
value.
</p>
<p>
Partial output is shown here. The list of names and values may
differ for your server. The meaning of each variable is given in
<a class="xref" href="server-status-variables.html" title="7.1.10 Server Status Variables">
Section 7.1.10, “Server Status Variables”
</a>
.
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa8856977"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SHOW</span> <span class="token keyword">STATUS</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> Variable_name <span class="token punctuation">|</span> Value <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> Aborted_clients <span class="token punctuation">|</span> 0 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Aborted_connects <span class="token punctuation">|</span> 0 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Bytes_received <span class="token punctuation">|</span> 155372598 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Bytes_sent <span class="token punctuation">|</span> 1176560426 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Connections <span class="token punctuation">|</span> 30023 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Created_tmp_disk_tables <span class="token punctuation">|</span> 0 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Created_tmp_tables <span class="token punctuation">|</span> 8340 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Created_tmp_files <span class="token punctuation">|</span> 60 <span class="token punctuation">|</span></span>
<span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span>
<span class="token output"><span class="token punctuation">|</span> Open_tables <span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Open_files <span class="token punctuation">|</span> 2 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Open_streams <span class="token punctuation">|</span> 0 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Opened_tables <span class="token punctuation">|</span> 44600 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Questions <span class="token punctuation">|</span> 2026873 <span class="token punctuation">|</span></span>
<span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span>
<span class="token output"><span class="token punctuation">|</span> Table_locks_immediate <span class="token punctuation">|</span> 1920382 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Table_locks_waited <span class="token punctuation">|</span> 0 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Threads_cached <span class="token punctuation">|</span> 0 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Threads_created <span class="token punctuation">|</span> 30022 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Threads_connected <span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Threads_running <span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Uptime <span class="token punctuation">|</span> 80380 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
<p>
With a
<a class="link" href="string-comparison-functions.html#operator_like">
<code class="literal">
LIKE
</code>
</a>
clause, the statement
displays only rows for those variables with names that match the
pattern:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa45715258"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SHOW</span> <span class="token keyword">STATUS</span> <span class="token operator">LIKE</span> <span class="token string">'Key%'</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> Variable_name <span class="token punctuation">|</span> Value <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> Key_blocks_used <span class="token punctuation">|</span> 14955 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Key_read_requests <span class="token punctuation">|</span> 96854827 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Key_reads <span class="token punctuation">|</span> 162040 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Key_write_requests <span class="token punctuation">|</span> 7589728 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Key_writes <span class="token punctuation">|</span> 3813196 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/innodb-on-disk-structures.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h2 class="title">
<a name="innodb-on-disk-structures">
</a>
17.6 InnoDB On-Disk Structures
</h2>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="innodb-tables.html">
17.6.1 Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="innodb-indexes.html">
17.6.2 Indexes
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="innodb-tablespace.html">
17.6.3 Tablespaces
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="innodb-doublewrite-buffer.html">
17.6.4 Doublewrite Buffer
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="innodb-redo-log.html">
17.6.5 Redo Log
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="innodb-undo-logs.html">
17.6.6 Undo Logs
</a>
</span>
</dt>
</dl>
</div>
<a class="indexterm" name="idm46045166876096">
</a>
<p>
This section describes
<code class="literal">
InnoDB
</code>
on-disk structures
and related topics.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/charset-unicode-ucs2.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="charset-unicode-ucs2">
</a>
12.9.4 The ucs2 Character Set (UCS-2 Unicode Encoding)
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045216597408">
</a>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
The
<code class="literal">
ucs2
</code>
character set is deprecated;
expect it to be removed in a future MySQL release. You should
use
<code class="literal">
utf8mb4
</code>
instead.
</p>
</div>
<p>
In UCS-2, every character is represented by a 2-byte Unicode
code with the most significant byte first. For example:
<code class="literal">
LATIN CAPITAL LETTER A
</code>
has the code
<code class="literal">
0x0041
</code>
and it is stored as a 2-byte sequence:
<code class="literal">
0x00 0x41
</code>
.
<code class="literal">
CYRILLIC SMALL LETTER
YERU
</code>
(Unicode
<code class="literal">
0x044B
</code>
) is stored as
a 2-byte sequence:
<code class="literal">
0x04 0x4B
</code>
. For Unicode
characters and their codes, please refer to the
<a class="ulink" href="http://www.unicode.org/" target="_blank">
Unicode Consortium
website
</a>
.
</p>
<p>
The
<code class="literal">
ucs2
</code>
character set has these
characteristics:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Supports BMP characters only (no support for supplementary
characters)
</p>
</li>
<li class="listitem">
<p>
Uses a fixed-length 16-bit encoding and requires two bytes
per character.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-memory-summary-tables.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="performance-schema-memory-summary-tables">
</a>
29.12.20.10 Memory Summary Tables
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045068181632">
</a>
<a class="indexterm" name="idm46045068180176">
</a>
<a class="indexterm" name="idm46045068178656">
</a>
<a class="indexterm" name="idm46045068177136">
</a>
<a class="indexterm" name="idm46045068175616">
</a>
<a class="indexterm" name="idm46045068174096">
</a>
<a class="indexterm" name="idm46045068172576">
</a>
<a class="indexterm" name="idm46045068171056">
</a>
<a class="indexterm" name="idm46045068169536">
</a>
<a class="indexterm" name="idm46045068168016">
</a>
<p>
The Performance Schema instruments memory usage and aggregates
memory usage statistics, detailed by these factors:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Type of memory used (various caches, internal buffers, and
so forth)
</p>
</li>
<li class="listitem">
<p>
Thread, account, user, host indirectly performing the
memory operation
</p>
</li>
</ul>
</div>
<p>
The Performance Schema instruments the following aspects of
memory use
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Memory sizes used
</p>
</li>
<li class="listitem">
<p>
Operation counts
</p>
</li>
<li class="listitem">
<p>
Low and high water marks
</p>
</li>
</ul>
</div>
<p>
Memory sizes help to understand or tune the memory consumption
of the server.
</p>
<p>
Operation counts help to understand or tune the overall
pressure the server is putting on the memory allocator, which
has an impact on performance. Allocating a single byte one
million times is not the same as allocating one million bytes
a single time; tracking both sizes and counts can expose the
difference.
</p>
<p>
Low and high water marks are critical to detect workload
spikes, overall workload stability, and possible memory leaks.
</p>
<p>
Memory summary tables do not contain timing information
because memory events are not timed.
</p>
<p>
For information about collecting memory usage data, see
<a class="xref" href="performance-schema-memory-summary-tables.html#memory-instrumentation-behavior" title="Memory Instrumentation Behavior">
Memory Instrumentation Behavior
</a>
.
</p>
<p>
Example memory event summary information:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa55288007"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token operator">*</span>
<span class="token keyword">FROM</span> performance_schema<span class="token punctuation">.</span>memory_summary_global_by_event_name
<span class="token keyword">WHERE</span> EVENT_NAME <span class="token operator">=</span> <span class="token string">'memory/sql/TABLE'</span>\G
<span class="token output"><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span> 1. row <span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span>
EVENT_NAME<span class="token punctuation">:</span> memory/sql/TABLE
COUNT_ALLOC<span class="token punctuation">:</span> 1381
COUNT_FREE<span class="token punctuation">:</span> 924
SUM_NUMBER_OF_BYTES_ALLOC<span class="token punctuation">:</span> 2059873
SUM_NUMBER_OF_BYTES_FREE<span class="token punctuation">:</span> 1407432
LOW_COUNT_USED<span class="token punctuation">:</span> 0
CURRENT_COUNT_USED<span class="token punctuation">:</span> 457
HIGH_COUNT_USED<span class="token punctuation">:</span> 461
LOW_NUMBER_OF_BYTES_USED<span class="token punctuation">:</span> 0
CURRENT_NUMBER_OF_BYTES_USED<span class="token punctuation">:</span> 652441
HIGH_NUMBER_OF_BYTES_USED<span class="token punctuation">:</span> 669269</span></code></pre>
</div>
<p>
Each memory summary table has one or more grouping columns to
indicate how the table aggregates events. Event names refer to
names of event instruments in the
<a class="link" href="performance-schema-setup-instruments-table.html" title="29.12.2.3 The setup_instruments Table">
<code class="literal">
setup_instruments
</code>
</a>
table:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="link" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
<code class="literal">
memory_summary_by_account_by_event_name
</code>
</a>
has
<code class="literal">
USER
</code>
,
<code class="literal">
HOST
</code>
, and
<code class="literal">
EVENT_NAME
</code>
columns. Each row summarizes
events for a given account (user and host combination) and
event name.
</p>
</li>
<li class="listitem">
<p>
<a class="link" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
<code class="literal">
memory_summary_by_host_by_event_name
</code>
</a>
has
<code class="literal">
HOST
</code>
and
<code class="literal">
EVENT_NAME
</code>
columns. Each row summarizes
events for a given host and event name.
</p>
</li>
<li class="listitem">
<p>
<a class="link" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
<code class="literal">
memory_summary_by_thread_by_event_name
</code>
</a>
has
<code class="literal">
THREAD_ID
</code>
and
<code class="literal">
EVENT_NAME
</code>
columns. Each row summarizes
events for a given thread and event name.
</p>
</li>
<li class="listitem">
<p>
<a class="link" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
<code class="literal">
memory_summary_by_user_by_event_name
</code>
</a>
has
<code class="literal">
USER
</code>
and
<code class="literal">
EVENT_NAME
</code>
columns. Each row summarizes
events for a given user and event name.
</p>
</li>
<li class="listitem">
<p>
<a class="link" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
<code class="literal">
memory_summary_global_by_event_name
</code>
</a>
has an
<code class="literal">
EVENT_NAME
</code>
column. Each row
summarizes events for a given event name.
</p>
</li>
</ul>
</div>
<p>
Each memory summary table has these summary columns containing
aggregated values:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
COUNT_ALLOC
</code>
,
<code class="literal">
COUNT_FREE
</code>
</p>
<p>
The aggregated numbers of calls to memory-allocation and
memory-free functions.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SUM_NUMBER_OF_BYTES_ALLOC
</code>
,
<code class="literal">
SUM_NUMBER_OF_BYTES_FREE
</code>
</p>
<p>
The aggregated sizes of allocated and freed memory blocks.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
CURRENT_COUNT_USED
</code>
</p>
<p>
The aggregated number of currently allocated blocks that
have not been freed yet. This is a convenience column,
equal to
<code class="literal">
COUNT_ALLOC
</code>
−
<code class="literal">
COUNT_FREE
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
CURRENT_NUMBER_OF_BYTES_USED
</code>
</p>
<p>
The aggregated size of currently allocated memory blocks
that have not been freed yet. This is a convenience
column, equal to
<code class="literal">
SUM_NUMBER_OF_BYTES_ALLOC
</code>
−
<code class="literal">
SUM_NUMBER_OF_BYTES_FREE
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LOW_COUNT_USED
</code>
,
<code class="literal">
HIGH_COUNT_USED
</code>
</p>
<p>
The low and high water marks corresponding to the
<code class="literal">
CURRENT_COUNT_USED
</code>
column.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LOW_NUMBER_OF_BYTES_USED
</code>
,
<code class="literal">
HIGH_NUMBER_OF_BYTES_USED
</code>
</p>
<p>
The low and high water marks corresponding to the
<code class="literal">
CURRENT_NUMBER_OF_BYTES_USED
</code>
column.
</p>
</li>
</ul>
</div>
<p>
The memory summary tables have these indexes:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="link" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
<code class="literal">
memory_summary_by_account_by_event_name
</code>
</a>
:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
Primary key on (
<code class="literal">
USER
</code>
,
<code class="literal">
HOST
</code>
,
<code class="literal">
EVENT_NAME
</code>
)
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
<a class="link" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
<code class="literal">
memory_summary_by_host_by_event_name
</code>
</a>
:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
Primary key on (
<code class="literal">
HOST
</code>
,
<code class="literal">
EVENT_NAME
</code>
)
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
<a class="link" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
<code class="literal">
memory_summary_by_thread_by_event_name
</code>
</a>
:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
Primary key on (
<code class="literal">
THREAD_ID
</code>
,
<code class="literal">
EVENT_NAME
</code>
)
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
<a class="link" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
<code class="literal">
memory_summary_by_user_by_event_name
</code>
</a>
:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
Primary key on (
<code class="literal">
USER
</code>
,
<code class="literal">
EVENT_NAME
</code>
)
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
<a class="link" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
<code class="literal">
memory_summary_global_by_event_name
</code>
</a>
:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
Primary key on (
<code class="literal">
EVENT_NAME
</code>
)
</p>
</li>
</ul>
</div>
</li>
</ul>
</div>
<p>
<a class="link" href="truncate-table.html" title="15.1.37 TRUNCATE TABLE Statement">
<code class="literal">
TRUNCATE TABLE
</code>
</a>
is permitted for
memory summary tables. It has these effects:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
In general, truncation resets the baseline for statistics,
but does not change the server state. That is, truncating
a memory table does not free memory.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
COUNT_ALLOC
</code>
and
<code class="literal">
COUNT_FREE
</code>
are reset to a new baseline,
by reducing each counter by the same value.
</p>
</li>
<li class="listitem">
<p>
Likewise,
<code class="literal">
SUM_NUMBER_OF_BYTES_ALLOC
</code>
and
<code class="literal">
SUM_NUMBER_OF_BYTES_FREE
</code>
are reset to a
new baseline.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LOW_COUNT_USED
</code>
and
<code class="literal">
HIGH_COUNT_USED
</code>
are reset to
<code class="literal">
CURRENT_COUNT_USED
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LOW_NUMBER_OF_BYTES_USED
</code>
and
<code class="literal">
HIGH_NUMBER_OF_BYTES_USED
</code>
are reset to
<code class="literal">
CURRENT_NUMBER_OF_BYTES_USED
</code>
.
</p>
</li>
</ul>
</div>
<p>
In addition, each memory summary table that is aggregated by
account, host, user, or thread is implicitly truncated by
truncation of the connection table on which it depends, or
truncation of
<a class="link" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
<code class="literal">
memory_summary_global_by_event_name
</code>
</a>
.
For details, see
<a class="xref" href="performance-schema-connection-tables.html" title="29.12.8 Performance Schema Connection Tables">
Section 29.12.8, “Performance Schema Connection Tables”
</a>
.
</p>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="memory-instrumentation-behavior">
</a>
Memory Instrumentation Behavior
</h5>
</div>
</div>
</div>
<p>
Memory instruments are listed in the
<a class="link" href="performance-schema-setup-instruments-table.html" title="29.12.2.3 The setup_instruments Table">
<code class="literal">
setup_instruments
</code>
</a>
table and
have names of the form
<code class="literal">
memory/
<em class="replaceable">
<code>
code_area
</code>
</em>
/
<em class="replaceable">
<code>
instrument_name
</code>
</em>
</code>
.
Memory instrumentation is enabled by default.
</p>
<p>
Instruments named with the prefix
<code class="literal">
memory/performance_schema/
</code>
expose how
much memory is allocated for internal buffers in the
Performance Schema itself. The
<code class="literal">
memory/performance_schema/
</code>
instruments
are built in, always enabled, and cannot be disabled at
startup or runtime. Built-in memory instruments are
displayed only in the
<a class="link" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
<code class="literal">
memory_summary_global_by_event_name
</code>
</a>
table.
</p>
<p>
To control memory instrumentation state at server startup,
use lines like these in your
<code class="filename">
my.cnf
</code>
file:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Enable:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-ini"><div class="docs-select-all right" id="sa53367503"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-ini"><span class="token selector">[mysqld]</span>
<span class="token constant">performance-schema-instrument</span><span class="token attr-value"><span class="token punctuation">=</span>'memory/%=ON'</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
Disable:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-ini"><div class="docs-select-all right" id="sa53359468"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-ini"><span class="token selector">[mysqld]</span>
<span class="token constant">performance-schema-instrument</span><span class="token attr-value"><span class="token punctuation">=</span>'memory/%=OFF'</span></code></pre>
</div>
</li>
</ul>
</div>
<p>
To control memory instrumentation state at runtime, update
the
<code class="literal">
ENABLED
</code>
column of the relevant
instruments in the
<a class="link" href="performance-schema-setup-instruments-table.html" title="29.12.2.3 The setup_instruments Table">
<code class="literal">
setup_instruments
</code>
</a>
table:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Enable:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa89918947"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> performance_schema<span class="token punctuation">.</span>setup_instruments
<span class="token keyword">SET</span> ENABLED <span class="token operator">=</span> <span class="token string">'YES'</span>
<span class="token keyword">WHERE</span> <span class="token keyword">NAME</span> <span class="token operator">LIKE</span> <span class="token string">'memory/%'</span><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
Disable:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa10096496"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> performance_schema<span class="token punctuation">.</span>setup_instruments
<span class="token keyword">SET</span> ENABLED <span class="token operator">=</span> <span class="token string">'NO'</span>
<span class="token keyword">WHERE</span> <span class="token keyword">NAME</span> <span class="token operator">LIKE</span> <span class="token string">'memory/%'</span><span class="token punctuation">;</span></code></pre>
</div>
</li>
</ul>
</div>
<p>
For memory instruments, the
<code class="literal">
TIMED
</code>
column
in
<a class="link" href="performance-schema-setup-instruments-table.html" title="29.12.2.3 The setup_instruments Table">
<code class="literal">
setup_instruments
</code>
</a>
is ignored
because memory operations are not timed.
</p>
<p>
When a thread in the server executes a memory allocation
that has been instrumented, these rules apply:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
If the thread is not instrumented or the memory
instrument is not enabled, the memory block allocated is
not instrumented.
</p>
</li>
<li class="listitem">
<p>
Otherwise (that is, both the thread and the instrument
are enabled), the memory block allocated is
instrumented.
</p>
</li>
</ul>
</div>
<p>
For deallocation, these rules apply:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
If a memory allocation operation was instrumented, the
corresponding free operation is instrumented, regardless
of the current instrument or thread enabled status.
</p>
</li>
<li class="listitem">
<p>
If a memory allocation operation was not instrumented,
the corresponding free operation is not instrumented,
regardless of the current instrument or thread enabled
status.
</p>
</li>
</ul>
</div>
<p>
For the per-thread statistics, the following rules apply.
</p>
<p>
When an instrumented memory block of size
<em class="replaceable">
<code>
N
</code>
</em>
is allocated, the Performance
Schema makes these updates to memory summary table columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
COUNT_ALLOC
</code>
: Increased by 1
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
CURRENT_COUNT_USED
</code>
: Increased by 1
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
HIGH_COUNT_USED
</code>
: Increased if
<code class="literal">
CURRENT_COUNT_USED
</code>
is a new maximum
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SUM_NUMBER_OF_BYTES_ALLOC
</code>
: Increased
by
<em class="replaceable">
<code>
N
</code>
</em>
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
CURRENT_NUMBER_OF_BYTES_USED
</code>
:
Increased by
<em class="replaceable">
<code>
N
</code>
</em>
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
HIGH_NUMBER_OF_BYTES_USED
</code>
: Increased
if
<code class="literal">
CURRENT_NUMBER_OF_BYTES_USED
</code>
is a
new maximum
</p>
</li>
</ul>
</div>
<p>
When an instrumented memory block is deallocated, the
Performance Schema makes these updates to memory summary
table columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
COUNT_FREE
</code>
: Increased by 1
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
CURRENT_COUNT_USED
</code>
: Decreased by 1
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LOW_COUNT_USED
</code>
: Decreased if
<code class="literal">
CURRENT_COUNT_USED
</code>
is a new minimum
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SUM_NUMBER_OF_BYTES_FREE
</code>
: Increased
by
<em class="replaceable">
<code>
N
</code>
</em>
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
CURRENT_NUMBER_OF_BYTES_USED
</code>
:
Decreased by
<em class="replaceable">
<code>
N
</code>
</em>
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LOW_NUMBER_OF_BYTES_USED
</code>
: Decreased
if
<code class="literal">
CURRENT_NUMBER_OF_BYTES_USED
</code>
is a
new minimum
</p>
</li>
</ul>
</div>
<p>
For higher-level aggregates (global, by account, by user, by
host), the same rules apply as expected for low and high
water marks.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
LOW_COUNT_USED
</code>
and
<code class="literal">
LOW_NUMBER_OF_BYTES_USED
</code>
are lower
estimates. The value reported by the Performance Schema
is guaranteed to be less than or equal to the lowest
count or size of memory effectively used at runtime.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
HIGH_COUNT_USED
</code>
and
<code class="literal">
HIGH_NUMBER_OF_BYTES_USED
</code>
are higher
estimates. The value reported by the Performance Schema
is guaranteed to be greater than or equal to the highest
count or size of memory effectively used at runtime.
</p>
</li>
</ul>
</div>
<p>
For lower estimates in summary tables other than
<a class="link" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
<code class="literal">
memory_summary_global_by_event_name
</code>
</a>
,
it is possible for values to go negative if memory ownership
is transferred between threads.
</p>
<p>
Here is an example of estimate computation; but note that
estimate implementation is subject to change:
</p>
<p>
Thread 1 uses memory in the range from 1MB to 2MB during
execution, as reported by the
<code class="literal">
LOW_NUMBER_OF_BYTES_USED
</code>
and
<code class="literal">
HIGH_NUMBER_OF_BYTES_USED
</code>
columns of the
<a class="link" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
<code class="literal">
memory_summary_by_thread_by_event_name
</code>
</a>
table.
</p>
<p>
Thread 2 uses memory in the range from 10MB to 12MB during
execution, as reported likewise.
</p>
<p>
When these two threads belong to the same user account, the
per-account summary estimates that this account used memory
in the range from 11MB to 14MB. That is, the
<code class="literal">
LOW_NUMBER_OF_BYTES_USED
</code>
for the higher
level aggregate is the sum of each
<code class="literal">
LOW_NUMBER_OF_BYTES_USED
</code>
(assuming the
worst case). Likewise, the
<code class="literal">
HIGH_NUMBER_OF_BYTES_USED
</code>
for the higher
level aggregate is the sum of each
<code class="literal">
HIGH_NUMBER_OF_BYTES_USED
</code>
(assuming the
worst case).
</p>
<p>
11MB is a lower estimate that can occur only if both threads
hit the low usage mark at the same time.
</p>
<p>
14MB is a higher estimate that can occur only if both
threads hit the high usage mark at the same time.
</p>
<p>
The real memory usage for this account could have been in
the range from 11.5MB to 13.5MB.
</p>
<p>
For capacity planning, reporting the worst case is actually
the desired behavior, as it shows what can potentially
happen when sessions are uncorrelated, which is typically
the case.
</p>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/log-destinations.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="log-destinations">
</a>
7.4.1 Selecting General Query Log and Slow Query Log Output Destinations
</h3>
</div>
</div>
</div>
<p>
MySQL Server provides flexible control over the destination of
output written to the general query log and the slow query log, if
those logs are enabled. Possible destinations for log entries are
log files or the
<code class="literal">
general_log
</code>
and
<code class="literal">
slow_log
</code>
tables in the
<code class="literal">
mysql
</code>
system database. File output, table output, or both can be
selected.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="xref" href="log-destinations.html#log-destinations-startup" title="Log Control at Server Startup">
Log Control at Server Startup
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="log-destinations.html#log-destinations-runtime" title="Log Control at Runtime">
Log Control at Runtime
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="log-destinations.html#log-destinations-tables" title="Log Table Benefits and Characteristics">
Log Table Benefits and Characteristics
</a>
</p>
</li>
</ul>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="log-destinations-startup">
</a>
Log Control at Server Startup
</h4>
</div>
</div>
</div>
<p>
The
<a class="link" href="server-system-variables.html#sysvar_log_output">
<code class="literal">
log_output
</code>
</a>
system variable
specifies the destination for log output. Setting this variable
does not in itself enable the logs; they must be enabled
separately.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
If
<a class="link" href="server-system-variables.html#sysvar_log_output">
<code class="literal">
log_output
</code>
</a>
is not
specified at startup, the default logging destination is
<code class="literal">
FILE
</code>
.
</p>
</li>
<li class="listitem">
<p>
If
<a class="link" href="server-system-variables.html#sysvar_log_output">
<code class="literal">
log_output
</code>
</a>
is specified
at startup, its value is a list one or more comma-separated
words chosen from
<code class="literal">
TABLE
</code>
(log to tables),
<code class="literal">
FILE
</code>
(log to files), or
<code class="literal">
NONE
</code>
(do not log to tables or files).
<code class="literal">
NONE
</code>
, if present, takes precedence over
any other specifiers.
</p>
</li>
</ul>
</div>
<p>
The
<a class="link" href="server-system-variables.html#sysvar_general_log">
<code class="literal">
general_log
</code>
</a>
system variable
controls logging to the general query log for the selected log
destinations. If specified at server startup,
<a class="link" href="server-system-variables.html#sysvar_general_log">
<code class="literal">
general_log
</code>
</a>
takes an optional
argument of 1 or 0 to enable or disable the log. To specify a
file name other than the default for file logging, set the
<a class="link" href="server-system-variables.html#sysvar_general_log_file">
<code class="literal">
general_log_file
</code>
</a>
variable.
Similarly, the
<a class="link" href="server-system-variables.html#sysvar_slow_query_log">
<code class="literal">
slow_query_log
</code>
</a>
variable controls logging to the slow query log for the selected
destinations and setting
<a class="link" href="server-system-variables.html#sysvar_slow_query_log_file">
<code class="literal">
slow_query_log_file
</code>
</a>
specifies a
file name for file logging. If either log is enabled, the server
opens the corresponding log file and writes startup messages to
it. However, further logging of queries to the file does not
occur unless the
<code class="literal">
FILE
</code>
log destination is
selected.
</p>
<p>
Examples:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
To write general query log entries to the log table and the
log file, use
<a class="link" href="server-system-variables.html#sysvar_log_output">
<code class="option">
--log_output=TABLE,FILE
</code>
</a>
to
select both log destinations and
<a class="link" href="server-system-variables.html#sysvar_general_log">
<code class="option">
--general_log
</code>
</a>
to enable the
general query log.
</p>
</li>
<li class="listitem">
<p>
To write general and slow query log entries only to the log
tables, use
<a class="link" href="server-system-variables.html#sysvar_log_output">
<code class="option">
--log_output=TABLE
</code>
</a>
to select
tables as the log destination and
<a class="link" href="server-system-variables.html#sysvar_general_log">
<code class="option">
--general_log
</code>
</a>
and
<a class="link" href="server-system-variables.html#sysvar_slow_query_log">
<code class="option">
--slow_query_log
</code>
</a>
to enable
both logs.
</p>
</li>
<li class="listitem">
<p>
To write slow query log entries only to the log file, use
<a class="link" href="server-system-variables.html#sysvar_log_output">
<code class="option">
--log_output=FILE
</code>
</a>
to select
files as the log destination and
<a class="link" href="server-system-variables.html#sysvar_slow_query_log">
<code class="option">
--slow_query_log
</code>
</a>
to enable
the slow query log. In this case, because the default log
destination is
<code class="literal">
FILE
</code>
, you could omit the
<a class="link" href="server-system-variables.html#sysvar_log_output">
<code class="literal">
log_output
</code>
</a>
setting.
</p>
</li>
</ul>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="log-destinations-runtime">
</a>
Log Control at Runtime
</h4>
</div>
</div>
</div>
<p>
The system variables associated with log tables and files enable
runtime control over logging:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
The
<a class="link" href="server-system-variables.html#sysvar_log_output">
<code class="literal">
log_output
</code>
</a>
variable
indicates the current logging destination. It can be
modified at runtime to change the destination.
</p>
</li>
<li class="listitem">
<p>
The
<a class="link" href="server-system-variables.html#sysvar_general_log">
<code class="literal">
general_log
</code>
</a>
and
<a class="link" href="server-system-variables.html#sysvar_slow_query_log">
<code class="literal">
slow_query_log
</code>
</a>
variables
indicate whether the general query log and slow query log
are enabled (
<code class="literal">
ON
</code>
) or disabled
(
<code class="literal">
OFF
</code>
). You can set these variables at
runtime to control whether the logs are enabled.
</p>
</li>
<li class="listitem">
<p>
The
<a class="link" href="server-system-variables.html#sysvar_general_log_file">
<code class="literal">
general_log_file
</code>
</a>
and
<a class="link" href="server-system-variables.html#sysvar_slow_query_log_file">
<code class="literal">
slow_query_log_file
</code>
</a>
variables indicate the names of the general query log and
slow query log files. You can set these variables at server
startup or at runtime to change the names of the log files.
</p>
</li>
<li class="listitem">
<p>
To disable or enable general query logging for the current
session, set the session
<a class="link" href="server-system-variables.html#sysvar_sql_log_off">
<code class="literal">
sql_log_off
</code>
</a>
variable to
<code class="literal">
ON
</code>
or
<code class="literal">
OFF
</code>
. (This
assumes that the general query log itself is enabled.)
</p>
</li>
</ul>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="log-destinations-tables">
</a>
Log Table Benefits and Characteristics
</h4>
</div>
</div>
</div>
<p>
The use of tables for log output offers the following benefits:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Log entries have a standard format. To display the current
structure of the log tables, use these statements:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa55802873"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SHOW</span> <span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> mysql<span class="token punctuation">.</span>general_log<span class="token punctuation">;</span>
<span class="token keyword">SHOW</span> <span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> mysql<span class="token punctuation">.</span>slow_log<span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
Log contents are accessible through SQL statements. This
enables the use of queries that select only those log
entries that satisfy specific criteria. For example, to
select log contents associated with a particular client
(which can be useful for identifying problematic queries
from that client), it is easier to do this using a log table
than a log file.
</p>
</li>
<li class="listitem">
<p>
Logs are accessible remotely through any client that can
connect to the server and issue queries (if the client has
the appropriate log table privileges). It is not necessary
to log in to the server host and directly access the file
system.
</p>
</li>
</ul>
</div>
<p>
The log table implementation has the following characteristics:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
In general, the primary purpose of log tables is to provide
an interface for users to observe the runtime execution of
the server, not to interfere with its runtime execution.
</p>
</li>
<li class="listitem">
<p>
<a class="link" href="create-table.html" title="15.1.20 CREATE TABLE Statement">
<code class="literal">
CREATE TABLE
</code>
</a>
,
<a class="link" href="alter-table.html" title="15.1.9 ALTER TABLE Statement">
<code class="literal">
ALTER TABLE
</code>
</a>
, and
<a class="link" href="drop-table.html" title="15.1.32 DROP TABLE Statement">
<code class="literal">
DROP TABLE
</code>
</a>
are valid
operations on a log table. For
<a class="link" href="alter-table.html" title="15.1.9 ALTER TABLE Statement">
<code class="literal">
ALTER
TABLE
</code>
</a>
and
<a class="link" href="drop-table.html" title="15.1.32 DROP TABLE Statement">
<code class="literal">
DROP
TABLE
</code>
</a>
, the log table cannot be in use and must be
disabled, as described later.
</p>
</li>
<li class="listitem">
<p>
By default, the log tables use the
<code class="literal">
CSV
</code>
storage engine that writes data in comma-separated values
format. For users who have access to the
<code class="filename">
.CSV
</code>
files that contain log table data,
the files are easy to import into other programs such as
spreadsheets that can process CSV input.
</p>
<p>
The log tables can be altered to use the
<code class="literal">
MyISAM
</code>
storage engine. You cannot use
<a class="link" href="alter-table.html" title="15.1.9 ALTER TABLE Statement">
<code class="literal">
ALTER TABLE
</code>
</a>
to alter a log
table that is in use. The log must be disabled first. No
engines other than
<code class="literal">
CSV
</code>
or
<code class="literal">
MyISAM
</code>
are legal for the log tables.
</p>
<p>
<a name="log-destinations-tables-open-files">
</a>
<b>
Log Tables and
<span class="quote">
“
<span class="quote">
Too many open files
</span>
”
</span>
Errors.
</b>
<a class="indexterm" name="idm46045259328384">
</a>
If you select
<code class="literal">
TABLE
</code>
as a log
destination and the log tables use the
<code class="literal">
CSV
</code>
storage engine, you may find that
disabling and enabling the general query log or slow query
log repeatedly at runtime results in a number of open file
descriptors for the
<code class="filename">
.CSV
</code>
file,
possibly resulting in a
<span class="quote">
“
<span class="quote">
Too many open files
</span>
”
</span>
error. To work around this issue, execute
<a class="link" href="flush.html" title="15.7.8.3 FLUSH Statement">
<code class="literal">
FLUSH
TABLES
</code>
</a>
or ensure that the value of
<a class="link" href="server-system-variables.html#sysvar_open_files_limit">
<code class="literal">
open_files_limit
</code>
</a>
is
greater than the value of
<a class="link" href="server-system-variables.html#sysvar_table_open_cache_instances">
<code class="literal">
table_open_cache_instances
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
To disable logging so that you can alter (or drop) a log
table, you can use the following strategy. The example uses
the general query log; the procedure for the slow query log
is similar but uses the
<code class="literal">
slow_log
</code>
table
and
<a class="link" href="server-system-variables.html#sysvar_slow_query_log">
<code class="literal">
slow_query_log
</code>
</a>
system
variable.
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa66804419"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SET</span> <span class="token variable">@old_log_state</span> <span class="token operator">=</span> <span class="token variable">@@GLOBAL.general_log</span><span class="token punctuation">;</span>
<span class="token keyword">SET</span> <span class="token keyword">GLOBAL</span> general_log <span class="token operator">=</span> <span class="token string">'OFF'</span><span class="token punctuation">;</span>
<span class="token keyword">ALTER</span> <span class="token keyword">TABLE</span> mysql<span class="token punctuation">.</span>general_log <span class="token keyword">ENGINE</span> <span class="token operator">=</span> MyISAM<span class="token punctuation">;</span>
<span class="token keyword">SET</span> <span class="token keyword">GLOBAL</span> general_log <span class="token operator">=</span> <span class="token variable">@old_log_state</span><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
<a class="link" href="truncate-table.html" title="15.1.37 TRUNCATE TABLE Statement">
<code class="literal">
TRUNCATE TABLE
</code>
</a>
is a valid
operation on a log table. It can be used to expire log
entries.
</p>
</li>
<li class="listitem">
<p>
<a class="link" href="rename-table.html" title="15.1.36 RENAME TABLE Statement">
<code class="literal">
RENAME TABLE
</code>
</a>
is a valid
operation on a log table. You can atomically rename a log
table (to perform log rotation, for example) using the
following strategy:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa58989856"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">USE</span> mysql<span class="token punctuation">;</span>
<span class="token keyword">DROP</span> <span class="token keyword">TABLE</span> <span class="token keyword">IF</span> <span class="token keyword">EXISTS</span> general_log2<span class="token punctuation">;</span>
<span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> general_log2 <span class="token operator">LIKE</span> general_log<span class="token punctuation">;</span>
<span class="token keyword">RENAME</span> <span class="token keyword">TABLE</span> general_log <span class="token keyword">TO</span> general_log_backup<span class="token punctuation">,</span> general_log2 <span class="token keyword">TO</span> general_log<span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
<a class="link" href="check-table.html" title="15.7.3.2 CHECK TABLE Statement">
<code class="literal">
CHECK TABLE
</code>
</a>
is a valid
operation on a log table.
</p>
</li>
<li class="listitem">
<p>
<a class="link" href="lock-tables.html" title="15.3.6 LOCK TABLES and UNLOCK TABLES Statements">
<code class="literal">
LOCK TABLES
</code>
</a>
cannot be used on
a log table.
</p>
</li>
<li class="listitem">
<p>
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
,
<a class="link" href="delete.html" title="15.2.2 DELETE Statement">
<code class="literal">
DELETE
</code>
</a>
, and
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
cannot be used on a
log table. These operations are permitted only internally to
the server itself.
</p>
</li>
<li class="listitem">
<p>
<a class="link" href="flush.html#flush-tables-with-read-lock">
<code class="literal">
FLUSH TABLES WITH READ LOCK
</code>
</a>
and the state of the
<a class="link" href="server-system-variables.html#sysvar_read_only">
<code class="literal">
read_only
</code>
</a>
system variable
have no effect on log tables. The server can always write to
the log tables.
</p>
</li>
<li class="listitem">
<p>
Entries written to the log tables are not written to the
binary log and thus are not replicated to replicas.
</p>
</li>
<li class="listitem">
<p>
To flush the log tables or log files, use
<a class="link" href="flush.html#flush-tables">
<code class="literal">
FLUSH TABLES
</code>
</a>
or
<a class="link" href="flush.html#flush-logs">
<code class="literal">
FLUSH LOGS
</code>
</a>
, respectively.
</p>
</li>
<li class="listitem">
<p>
Partitioning of log tables is not permitted.
</p>
</li>
<li class="listitem">
<p>
A
<a class="link" href="mysqldump.html" title="6.5.4 mysqldump — A Database Backup Program">
<span class="command">
<strong>
mysqldump
</strong>
</span>
</a>
dump includes statements to
recreate those tables so that they are not missing after
reloading the dump file. Log table contents are not dumped.
</p>
</li>
</ul>
</div>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/mysqld-server.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h2 class="title">
<a name="mysqld-server">
</a>
7.1 The MySQL Server
</h2>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="server-configuration.html">
7.1.1 Configuring the Server
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="server-configuration-defaults.html">
7.1.2 Server Configuration Defaults
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="server-configuration-validation.html">
7.1.3 Server Configuration Validation
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="server-option-variable-reference.html">
7.1.4 Server Option, System Variable, and Status Variable Reference
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="server-system-variable-reference.html">
7.1.5 Server System Variable Reference
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="server-status-variable-reference.html">
7.1.6 Server Status Variable Reference
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="server-options.html">
7.1.7 Server Command Options
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="server-system-variables.html">
7.1.8 Server System Variables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="using-system-variables.html">
7.1.9 Using System Variables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="server-status-variables.html">
7.1.10 Server Status Variables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="sql-mode.html">
7.1.11 Server SQL Modes
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="connection-management.html">
7.1.12 Connection Management
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="ipv6-support.html">
7.1.13 IPv6 Support
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="network-namespace-support.html">
7.1.14 Network Namespace Support
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="time-zone-support.html">
7.1.15 MySQL Server Time Zone Support
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="resource-groups.html">
7.1.16 Resource Groups
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="server-side-help-support.html">
7.1.17 Server-Side Help Support
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="session-state-tracking.html">
7.1.18 Server Tracking of Client Session State
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="server-shutdown.html">
7.1.19 The Server Shutdown Process
</a>
</span>
</dt>
</dl>
</div>
<a class="indexterm" name="idm46045302486064">
</a>
<a class="indexterm" name="idm46045302484576">
</a>
<p>
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
is the MySQL server. The following
discussion covers these MySQL server configuration topics:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Startup options that the server supports. You can specify these
options on the command line, through configuration files, or
both.
</p>
</li>
<li class="listitem">
<p>
Server system variables. These variables reflect the current
state and values of the startup options, some of which can be
modified while the server is running.
</p>
</li>
<li class="listitem">
<p>
Server status variables. These variables contain counters and
statistics about runtime operation.
</p>
</li>
<li class="listitem">
<p>
How to set the server SQL mode. This setting modifies certain
aspects of SQL syntax and semantics, for example for
compatibility with code from other database systems, or to
control the error handling for particular situations.
</p>
</li>
<li class="listitem">
<p>
How the server manages client connections.
</p>
</li>
<li class="listitem">
<p>
Configuring and using IPv6 and network namespace support.
</p>
</li>
<li class="listitem">
<p>
Configuring and using time zone support.
</p>
</li>
<li class="listitem">
<p>
Using resource groups.
</p>
</li>
<li class="listitem">
<p>
Server-side help capabilities.
</p>
</li>
<li class="listitem">
<p>
Capabilities provided to enable client session state changes.
</p>
</li>
<li class="listitem">
<p>
The server shutdown process. There are performance and
reliability considerations depending on the type of table
(transactional or nontransactional) and whether you use
replication.
</p>
</li>
</ul>
</div>
<p>
For listings of MySQL server variables and options that have been
added, deprecated, or removed in MySQL 8.4, see
<a class="xref" href="added-deprecated-removed.html" title="1.5 Server and Status Variables and Options Added, Deprecated, or Removed in MySQL 8.4 since 8.0">
Section 1.5, “Server and Status Variables and Options Added, Deprecated, or Removed in
MySQL 8.4 since 8.0”
</a>
.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
Not all storage engines are supported by all MySQL server binaries
and configurations. To find out how to determine which storage
engines your MySQL server installation supports, see
<a class="xref" href="show-engines.html" title="15.7.7.17 SHOW ENGINES Statement">
Section 15.7.7.17, “SHOW ENGINES Statement”
</a>
.
</p>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-events-statements-current-table.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="performance-schema-events-statements-current-table">
</a>
29.12.6.1 The events_statements_current Table
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045072837680">
</a>
<a class="indexterm" name="idm46045072836176">
</a>
<p>
The
<a class="link" href="performance-schema-events-statements-current-table.html" title="29.12.6.1 The events_statements_current Table">
<code class="literal">
events_statements_current
</code>
</a>
table contains current statement events. The table stores one
row per thread showing the current status of the thread's most
recent monitored statement event, so there is no system
variable for configuring the table size.
</p>
<p>
Of the tables that contain statement event rows,
<a class="link" href="performance-schema-events-statements-current-table.html" title="29.12.6.1 The events_statements_current Table">
<code class="literal">
events_statements_current
</code>
</a>
is the
most fundamental. Other tables that contain statement event
rows are logically derived from the current events. For
example, the
<a class="link" href="performance-schema-events-statements-history-table.html" title="29.12.6.2 The events_statements_history Table">
<code class="literal">
events_statements_history
</code>
</a>
and
<a class="link" href="performance-schema-events-statements-history-long-table.html" title="29.12.6.3 The events_statements_history_long Table">
<code class="literal">
events_statements_history_long
</code>
</a>
tables are collections of the most recent statement events
that have ended, up to a maximum number of rows per thread and
globally across all threads, respectively.
</p>
<p>
For more information about the relationship between the three
<code class="literal">
events_statements_
<em class="replaceable">
<code>
xxx
</code>
</em>
</code>
event tables, see
<a class="xref" href="performance-schema-event-tables.html" title="29.9 Performance Schema Tables for Current and Historical Events">
Section 29.9, “Performance Schema Tables for Current and Historical Events”
</a>
.
</p>
<p>
For information about configuring whether to collect statement
events, see
<a class="xref" href="performance-schema-statement-tables.html" title="29.12.6 Performance Schema Statement Event Tables">
Section 29.12.6, “Performance Schema Statement Event Tables”
</a>
.
</p>
<p>
The
<a class="link" href="performance-schema-events-statements-current-table.html" title="29.12.6.1 The events_statements_current Table">
<code class="literal">
events_statements_current
</code>
</a>
table has these columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
THREAD_ID
</code>
,
<code class="literal">
EVENT_ID
</code>
</p>
<p>
The thread associated with the event and the thread
current event number when the event starts. The
<code class="literal">
THREAD_ID
</code>
and
<code class="literal">
EVENT_ID
</code>
values taken together uniquely
identify the row. No two rows have the same pair of
values.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
END_EVENT_ID
</code>
</p>
<p>
This column is set to
<code class="literal">
NULL
</code>
when the
event starts and updated to the thread current event
number when the event ends.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
EVENT_NAME
</code>
</p>
<p>
The name of the instrument from which the event was
collected. This is a
<code class="literal">
NAME
</code>
value from
the
<a class="link" href="performance-schema-setup-instruments-table.html" title="29.12.2.3 The setup_instruments Table">
<code class="literal">
setup_instruments
</code>
</a>
table.
Instrument names may have multiple parts and form a
hierarchy, as discussed in
<a class="xref" href="performance-schema-instrument-naming.html" title="29.6 Performance Schema Instrument Naming Conventions">
Section 29.6, “Performance Schema Instrument Naming Conventions”
</a>
.
</p>
<p>
For SQL statements, the
<code class="literal">
EVENT_NAME
</code>
value initially is
<code class="literal">
statement/com/Query
</code>
until the statement is parsed, then changes to a more
appropriate value, as described in
<a class="xref" href="performance-schema-statement-tables.html" title="29.12.6 Performance Schema Statement Event Tables">
Section 29.12.6, “Performance Schema Statement Event Tables”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SOURCE
</code>
</p>
<p>
The name of the source file containing the instrumented
code that produced the event and the line number in the
file at which the instrumentation occurs. This enables you
to check the source to determine exactly what code is
involved.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
TIMER_START
</code>
,
<code class="literal">
TIMER_END
</code>
,
<code class="literal">
TIMER_WAIT
</code>
</p>
<p>
Timing information for the event. The unit for these
values is picoseconds (trillionths of a second). The
<code class="literal">
TIMER_START
</code>
and
<code class="literal">
TIMER_END
</code>
values indicate when event
timing started and ended.
<code class="literal">
TIMER_WAIT
</code>
is
the event elapsed time (duration).
</p>
<p>
If an event has not finished,
<code class="literal">
TIMER_END
</code>
is the current timer value and
<code class="literal">
TIMER_WAIT
</code>
is the time elapsed so far
(
<code class="literal">
TIMER_END
</code>
−
<code class="literal">
TIMER_START
</code>
).
</p>
<p>
If an event is produced from an instrument that has
<code class="literal">
TIMED = NO
</code>
, timing information is not
collected, and
<code class="literal">
TIMER_START
</code>
,
<code class="literal">
TIMER_END
</code>
, and
<code class="literal">
TIMER_WAIT
</code>
are all
<code class="literal">
NULL
</code>
.
</p>
<p>
For discussion of picoseconds as the unit for event times
and factors that affect time values, see
<a class="xref" href="performance-schema-timing.html" title="29.4.1 Performance Schema Event Timing">
Section 29.4.1, “Performance Schema Event Timing”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LOCK_TIME
</code>
</p>
<p>
The time spent waiting for table locks. This value is
computed in microseconds but normalized to picoseconds for
easier comparison with other Performance Schema timers.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SQL_TEXT
</code>
</p>
<p>
The text of the SQL statement. For a command not
associated with an SQL statement, the value is
<code class="literal">
NULL
</code>
.
</p>
<p>
The maximum space available for statement display is 1024
bytes by default. To change this value, set the
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_sql_text_length">
<code class="literal">
performance_schema_max_sql_text_length
</code>
</a>
system variable at server startup. (Changing this value
affects columns in other Performance Schema tables as
well. See
<a class="xref" href="performance-schema-statement-digests.html" title="29.10 Performance Schema Statement Digests and Sampling">
Section 29.10, “Performance Schema Statement Digests and Sampling”
</a>
.)
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
DIGEST
</code>
</p>
<p>
The statement digest SHA-256 value as a string of 64
hexadecimal characters, or
<code class="literal">
NULL
</code>
if the
<code class="literal">
statements_digest
</code>
consumer is
<code class="literal">
no
</code>
. For more information about
statement digesting, see
<a class="xref" href="performance-schema-statement-digests.html" title="29.10 Performance Schema Statement Digests and Sampling">
Section 29.10, “Performance Schema Statement Digests and Sampling”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
DIGEST_TEXT
</code>
</p>
<p>
The normalized statement digest text, or
<code class="literal">
NULL
</code>
if the
<code class="literal">
statements_digest
</code>
consumer is
<code class="literal">
no
</code>
. For more information about
statement digesting, see
<a class="xref" href="performance-schema-statement-digests.html" title="29.10 Performance Schema Statement Digests and Sampling">
Section 29.10, “Performance Schema Statement Digests and Sampling”
</a>
.
</p>
<p>
The
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_digest_length">
<code class="literal">
performance_schema_max_digest_length
</code>
</a>
system variable determines the maximum number of bytes
available per session for digest value storage. However,
the display length of statement digests may be longer than
the available buffer size due to encoding of statement
elements such as keywords and literal values in digest
buffer. Consequently, values selected from the
<code class="literal">
DIGEST_TEXT
</code>
column of statement event
tables may appear to exceed the
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_digest_length">
<code class="literal">
performance_schema_max_digest_length
</code>
</a>
value.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
CURRENT_SCHEMA
</code>
</p>
<p>
The default database for the statement,
<code class="literal">
NULL
</code>
if there is none.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
OBJECT_SCHEMA
</code>
,
<code class="literal">
OBJECT_NAME
</code>
,
<code class="literal">
OBJECT_TYPE
</code>
</p>
<p>
For nested statements (stored programs), these columns
contain information about the parent statement. Otherwise
they are
<code class="literal">
NULL
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
OBJECT_INSTANCE_BEGIN
</code>
</p>
<p>
This column identifies the statement. The value is the
address of an object in memory.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
MYSQL_ERRNO
</code>
</p>
<p>
The statement error number, from the statement diagnostics
area.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
RETURNED_SQLSTATE
</code>
</p>
<p>
The statement SQLSTATE value, from the statement
diagnostics area.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
MESSAGE_TEXT
</code>
</p>
<p>
The statement error message, from the statement
diagnostics area.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
ERRORS
</code>
</p>
<p>
Whether an error occurred for the statement. The value is
0 if the SQLSTATE value begins with
<code class="literal">
00
</code>
(completion) or
<code class="literal">
01
</code>
(warning). The value
is 1 is the SQLSTATE value is anything else.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
WARNINGS
</code>
</p>
<p>
The number of warnings, from the statement diagnostics
area.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
ROWS_AFFECTED
</code>
</p>
<p>
The number of rows affected by the statement. For a
description of the meaning of
<span class="quote">
“
<span class="quote">
affected,
</span>
”
</span>
see
<a class="ulink" href="/doc/c-api/8.4/en/mysql-affected-rows.html" target="_top">
mysql_affected_rows()
</a>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
ROWS_SENT
</code>
</p>
<p>
The number of rows returned by the statement.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
ROWS_EXAMINED
</code>
</p>
<p>
The number of rows examined by the server layer (not
counting any processing internal to storage engines).
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
CREATED_TMP_DISK_TABLES
</code>
</p>
<p>
Like the
<a class="link" href="server-status-variables.html#statvar_Created_tmp_disk_tables">
<code class="literal">
Created_tmp_disk_tables
</code>
</a>
status variable, but specific to the statement.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
CREATED_TMP_TABLES
</code>
</p>
<p>
Like the
<a class="link" href="server-status-variables.html#statvar_Created_tmp_tables">
<code class="literal">
Created_tmp_tables
</code>
</a>
status variable, but specific to the statement.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SELECT_FULL_JOIN
</code>
</p>
<p>
Like the
<a class="link" href="server-status-variables.html#statvar_Select_full_join">
<code class="literal">
Select_full_join
</code>
</a>
status
variable, but specific to the statement.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SELECT_FULL_RANGE_JOIN
</code>
</p>
<p>
Like the
<a class="link" href="server-status-variables.html#statvar_Select_full_range_join">
<code class="literal">
Select_full_range_join
</code>
</a>
status variable, but specific to the statement.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SELECT_RANGE
</code>
</p>
<p>
Like the
<a class="link" href="server-status-variables.html#statvar_Select_range">
<code class="literal">
Select_range
</code>
</a>
status variable, but specific to the statement.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SELECT_RANGE_CHECK
</code>
</p>
<p>
Like the
<a class="link" href="server-status-variables.html#statvar_Select_range_check">
<code class="literal">
Select_range_check
</code>
</a>
status variable, but specific to the statement.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SELECT_SCAN
</code>
</p>
<p>
Like the
<a class="link" href="server-status-variables.html#statvar_Select_scan">
<code class="literal">
Select_scan
</code>
</a>
status variable, but specific to the statement.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SORT_MERGE_PASSES
</code>
</p>
<p>
Like the
<a class="link" href="server-status-variables.html#statvar_Sort_merge_passes">
<code class="literal">
Sort_merge_passes
</code>
</a>
status
variable, but specific to the statement.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SORT_RANGE
</code>
</p>
<p>
Like the
<a class="link" href="server-status-variables.html#statvar_Sort_range">
<code class="literal">
Sort_range
</code>
</a>
status variable, but specific to the statement.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SORT_ROWS
</code>
</p>
<p>
Like the
<a class="link" href="server-status-variables.html#statvar_Sort_rows">
<code class="literal">
Sort_rows
</code>
</a>
status variable, but specific to the statement.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SORT_SCAN
</code>
</p>
<p>
Like the
<a class="link" href="server-status-variables.html#statvar_Sort_scan">
<code class="literal">
Sort_scan
</code>
</a>
status variable, but specific to the statement.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
NO_INDEX_USED
</code>
</p>
<p>
1 if the statement performed a table scan without using an
index, 0 otherwise.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
NO_GOOD_INDEX_USED
</code>
</p>
<p>
1 if the server found no good index to use for the
statement, 0 otherwise. For additional information, see
the description of the
<code class="literal">
Extra
</code>
column
from
<code class="literal">
EXPLAIN
</code>
output for the
<code class="literal">
Range checked for each record
</code>
value in
<a class="xref" href="explain-output.html" title="10.8.2 EXPLAIN Output Format">
Section 10.8.2, “EXPLAIN Output Format”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
NESTING_EVENT_ID
</code>
,
<code class="literal">
NESTING_EVENT_TYPE
</code>
,
<code class="literal">
NESTING_EVENT_LEVEL
</code>
</p>
<p>
These three columns are used with other columns to provide
information as follows for top-level (unnested) statements
and nested statements (executed within a stored program).
</p>
<p>
For top level statements:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-none"><div class="docs-select-all right" id="sa16458745"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-none">OBJECT_TYPE = NULL
OBJECT_SCHEMA = NULL
OBJECT_NAME = NULL
NESTING_EVENT_ID = the parent transaction EVENT_ID
NESTING_EVENT_TYPE = 'TRANSACTION'
NESTING_LEVEL = 0</code></pre>
</div>
<p>
For nested statements:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-none"><div class="docs-select-all right" id="sa20942061"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-none">OBJECT_TYPE = the parent statement object type
OBJECT_SCHEMA = the parent statement object schema
OBJECT_NAME = the parent statement object name
NESTING_EVENT_ID = the parent statement EVENT_ID
NESTING_EVENT_TYPE = 'STATEMENT'
NESTING_LEVEL = the parent statement NESTING_LEVEL plus one</code></pre>
</div>
</li>
<li class="listitem">
<p>
<code class="literal">
STATEMENT_ID
</code>
</p>
<p>
The query ID maintained by the server at the SQL level.
The value is unique for the server instance because these
IDs are generated using a global counter that is
incremented atomically.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
CPU_TIME
</code>
</p>
<p>
The time spent on CPU for the current thread, expressed in
picoseconds.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
MAX_CONTROLLED_MEMORY
</code>
</p>
<p>
Reports the maximum amount of controlled memory used by a
statement during execution.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
MAX_TOTAL_MEMORY
</code>
</p>
<p>
Reports the maximum amount of memory used by a statement
during execution.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
EXECUTION_ENGINE
</code>
</p>
<p>
The query execution engine. The value is either
<code class="literal">
PRIMARY
</code>
or
<code class="literal">
SECONDARY
</code>
. For use with HeatWave Service and
HeatWave, where the
<code class="literal">
PRIMARY
</code>
engine is
<code class="literal">
InnoDB
</code>
and the
<code class="literal">
SECONDARY
</code>
engine is HeatWave
(
<code class="literal">
RAPID
</code>
). For MySQL Community Edition Server, MySQL Enterprise Edition Server
(on-premise), and HeatWave Service without HeatWave, the value is
always
<code class="literal">
PRIMARY
</code>
.
</p>
</li>
</ul>
</div>
<p>
The
<a class="link" href="performance-schema-events-statements-current-table.html" title="29.12.6.1 The events_statements_current Table">
<code class="literal">
events_statements_current
</code>
</a>
table has these indexes:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Primary key on (
<code class="literal">
THREAD_ID
</code>
,
<code class="literal">
EVENT_ID
</code>
)
</p>
</li>
</ul>
</div>
<p>
<a class="link" href="truncate-table.html" title="15.1.37 TRUNCATE TABLE Statement">
<code class="literal">
TRUNCATE TABLE
</code>
</a>
is permitted for
the
<a class="link" href="performance-schema-events-statements-current-table.html" title="29.12.6.1 The events_statements_current Table">
<code class="literal">
events_statements_current
</code>
</a>
table. It removes the rows.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/sys-ps-is-thread-instrumented.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="sys-ps-is-thread-instrumented">
</a>
30.4.5.13 The ps_is_thread_instrumented() Function
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045060823568">
</a>
<a class="indexterm" name="idm46045060822112">
</a>
<p>
Returns
<code class="literal">
YES
</code>
or
<code class="literal">
NO
</code>
to
indicate whether Performance Schema instrumentation for a
given connection ID is enabled,
<code class="literal">
UNKNOWN
</code>
if
the ID is unknown, or
<code class="literal">
NULL
</code>
if the ID is
<code class="literal">
NULL
</code>
.
</p>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="sys-ps-is-thread-instrumented-parameters">
</a>
Parameters
</h5>
</div>
</div>
</div>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
in_connection_id BIGINT UNSIGNED
</code>
: The
connection ID. This is a value of the type given in the
<code class="literal">
PROCESSLIST_ID
</code>
column of the
Performance Schema
<a class="link" href="performance-schema-threads-table.html" title="29.12.22.8 The threads Table">
<code class="literal">
threads
</code>
</a>
table or the
<code class="literal">
Id
</code>
column of
<a class="link" href="show-processlist.html" title="15.7.7.31 SHOW PROCESSLIST Statement">
<code class="literal">
SHOW PROCESSLIST
</code>
</a>
output.
</p>
</li>
</ul>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="sys-ps-is-thread-instrumented-return-value">
</a>
Return Value
</h5>
</div>
</div>
</div>
<p>
An
<code class="literal">
ENUM('YES','NO','UNKNOWN')
</code>
value.
</p>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="sys-ps-is-thread-instrumented-example">
</a>
Example
</h5>
</div>
</div>
</div>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa1545051"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> sys<span class="token punctuation">.</span>ps_is_thread_instrumented<span class="token punctuation">(</span><span class="token number">43</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> sys.ps_is_thread_instrumented(43) <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> UNKNOWN <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> sys<span class="token punctuation">.</span>ps_is_thread_instrumented<span class="token punctuation">(</span><span class="token function">CONNECTION_ID</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> sys.ps_is_thread_instrumented(CONNECTION_ID()) <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> YES <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/ddl-rewriter.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="ddl-rewriter">
</a>
7.6.5 The ddl_rewriter Plugin
</h3>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="ddl-rewriter-installation.html">
7.6.5.1 Installing or Uninstalling ddl_rewriter
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="ddl-rewriter-options.html">
7.6.5.2 ddl_rewriter Plugin Options
</a>
</span>
</dt>
</dl>
</div>
<a class="indexterm" name="idm46045256232016">
</a>
<a class="indexterm" name="idm46045256230944">
</a>
<p>
MySQL 8.4 includes a
<code class="literal">
ddl_rewriter
</code>
plugin that modifies
<a class="link" href="create-table.html" title="15.1.20 CREATE TABLE Statement">
<code class="literal">
CREATE TABLE
</code>
</a>
statements received by the server before it parses and executes
them. The plugin removes
<code class="literal">
ENCRYPTION
</code>
,
<code class="literal">
DATA DIRECTORY
</code>
, and
<code class="literal">
INDEX
DIRECTORY
</code>
clauses, which may be helpful when restoring
tables from SQL dump files created from databases that are
encrypted or that have their tables stored outside the data
directory. For example, the plugin may enable restoring such dump
files into an unencrypted instance or in an environment where the
paths outside the data directory are not accessible.
</p>
<p>
Before using the
<code class="literal">
ddl_rewriter
</code>
plugin, install
it according to the instructions provided in
<a class="xref" href="ddl-rewriter-installation.html" title="7.6.5.1 Installing or Uninstalling ddl_rewriter">
Section 7.6.5.1, “Installing or Uninstalling ddl_rewriter”
</a>
.
</p>
<p>
<code class="literal">
ddl_rewriter
</code>
examines SQL statements received
by the server prior to parsing, rewriting them according to these
conditions:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
ddl_rewriter
</code>
considers only
<a class="link" href="create-table.html" title="15.1.20 CREATE TABLE Statement">
<code class="literal">
CREATE TABLE
</code>
</a>
statements, and
only if they are standalone statements that occur at the
beginning of an input line or at the beginning of prepared
statement text.
<code class="literal">
ddl_rewriter
</code>
does not
consider
<a class="link" href="create-table.html" title="15.1.20 CREATE TABLE Statement">
<code class="literal">
CREATE TABLE
</code>
</a>
statements within stored program definitions. Statements can
extend over multiple lines.
</p>
</li>
<li class="listitem">
<p>
Within statements considered for rewrite, instances of the
following clauses are rewritten and each instance replaced by
a single space:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
<code class="literal">
ENCRYPTION
</code>
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
DATA DIRECTORY
</code>
(at the table and
partition levels)
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
INDEX DIRECTORY
</code>
(at the table and
partition levels)
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
Rewriting does not depend on lettercase.
</p>
</li>
</ul>
</div>
<p>
If
<code class="literal">
ddl_rewriter
</code>
rewrites a statement, it
generates a warning:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa78026208"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> t <span class="token punctuation">(</span>i <span class="token datatype">INT</span><span class="token punctuation">)</span> <span class="token keyword">DATA</span> <span class="token keyword">DIRECTORY</span> <span class="token string">'/var/mysql/data'</span><span class="token punctuation">;</span>
<span class="token output">Query OK, 0 rows affected, 1 warning (0.03 sec)</span>
<span class="token prompt">mysql></span> <span class="token keyword">SHOW</span> <span class="token keyword">WARNINGS</span>\G
<span class="token output"><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span> 1. row <span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span>
Level<span class="token punctuation">:</span> Note
Code<span class="token punctuation">:</span> 1105
Message<span class="token punctuation">:</span> Query 'CREATE TABLE t (i INT) DATA DIRECTORY '/var/mysql/data''
rewritten to 'CREATE TABLE t (i INT) ' by a query rewrite plugin
</span><span class="token output">1 row in set (0.00 sec)</span></code></pre>
</div>
<p>
If the general query log or binary log is enabled, the server
writes to it statements as they appear after any rewriting by
<code class="literal">
ddl_rewriter
</code>
.
</p>
<p>
When installed,
<code class="literal">
ddl_rewriter
</code>
exposes the
Performance Schema
<code class="literal">
memory/rewriter/ddl_rewriter
</code>
instrument for tracking plugin memory use. See
<a class="xref" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
Section 29.12.20.10, “Memory Summary Tables”
</a>
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/alter-table-generated-columns.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="alter-table-generated-columns">
</a>
15.1.9.2 ALTER TABLE and Generated Columns
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045188596736">
</a>
<p>
<code class="literal">
ALTER TABLE
</code>
operations permitted for
generated columns are
<code class="literal">
ADD
</code>
,
<code class="literal">
MODIFY
</code>
, and
<code class="literal">
CHANGE
</code>
.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Generated columns can be added.
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa71258805"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> t1 <span class="token punctuation">(</span>c1 <span class="token datatype">INT</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">ALTER</span> <span class="token keyword">TABLE</span> t1 <span class="token keyword">ADD</span> <span class="token keyword">COLUMN</span> c2 <span class="token datatype">INT</span> <span class="token keyword">GENERATED</span> <span class="token keyword">ALWAYS</span> <span class="token keyword">AS</span> <span class="token punctuation">(</span>c1 <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">)</span> <span class="token keyword">STORED</span><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
The data type and expression of generated columns can be
modified.
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa191251"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> t1 <span class="token punctuation">(</span>c1 <span class="token datatype">INT</span><span class="token punctuation">,</span> c2 <span class="token datatype">INT</span> <span class="token keyword">GENERATED</span> <span class="token keyword">ALWAYS</span> <span class="token keyword">AS</span> <span class="token punctuation">(</span>c1 <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">)</span> <span class="token keyword">STORED</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">ALTER</span> <span class="token keyword">TABLE</span> t1 <span class="token keyword">MODIFY</span> <span class="token keyword">COLUMN</span> c2 <span class="token datatype">TINYINT</span> <span class="token keyword">GENERATED</span> <span class="token keyword">ALWAYS</span> <span class="token keyword">AS</span> <span class="token punctuation">(</span>c1 <span class="token operator">+</span> <span class="token number">5</span><span class="token punctuation">)</span> <span class="token keyword">STORED</span><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
Generated columns can be renamed or dropped, if no other
column refers to them.
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa40861212"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> t1 <span class="token punctuation">(</span>c1 <span class="token datatype">INT</span><span class="token punctuation">,</span> c2 <span class="token datatype">INT</span> <span class="token keyword">GENERATED</span> <span class="token keyword">ALWAYS</span> <span class="token keyword">AS</span> <span class="token punctuation">(</span>c1 <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">)</span> <span class="token keyword">STORED</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">ALTER</span> <span class="token keyword">TABLE</span> t1 <span class="token keyword">CHANGE</span> c2 c3 <span class="token datatype">INT</span> <span class="token keyword">GENERATED</span> <span class="token keyword">ALWAYS</span> <span class="token keyword">AS</span> <span class="token punctuation">(</span>c1 <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">)</span> <span class="token keyword">STORED</span><span class="token punctuation">;</span>
<span class="token keyword">ALTER</span> <span class="token keyword">TABLE</span> t1 <span class="token keyword">DROP</span> <span class="token keyword">COLUMN</span> c3<span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
Virtual generated columns cannot be altered to stored
generated columns, or vice versa. To work around this, drop
the column, then add it with the new definition.
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa17759601"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> t1 <span class="token punctuation">(</span>c1 <span class="token datatype">INT</span><span class="token punctuation">,</span> c2 <span class="token datatype">INT</span> <span class="token keyword">GENERATED</span> <span class="token keyword">ALWAYS</span> <span class="token keyword">AS</span> <span class="token punctuation">(</span>c1 <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">)</span> <span class="token keyword">VIRTUAL</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">ALTER</span> <span class="token keyword">TABLE</span> t1 <span class="token keyword">DROP</span> <span class="token keyword">COLUMN</span> c2<span class="token punctuation">;</span>
<span class="token keyword">ALTER</span> <span class="token keyword">TABLE</span> t1 <span class="token keyword">ADD</span> <span class="token keyword">COLUMN</span> c2 <span class="token datatype">INT</span> <span class="token keyword">GENERATED</span> <span class="token keyword">ALWAYS</span> <span class="token keyword">AS</span> <span class="token punctuation">(</span>c1 <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">)</span> <span class="token keyword">STORED</span><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
Nongenerated columns can be altered to stored but not
virtual generated columns.
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa11934309"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> t1 <span class="token punctuation">(</span>c1 <span class="token datatype">INT</span><span class="token punctuation">,</span> c2 <span class="token datatype">INT</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">ALTER</span> <span class="token keyword">TABLE</span> t1 <span class="token keyword">MODIFY</span> <span class="token keyword">COLUMN</span> c2 <span class="token datatype">INT</span> <span class="token keyword">GENERATED</span> <span class="token keyword">ALWAYS</span> <span class="token keyword">AS</span> <span class="token punctuation">(</span>c1 <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">)</span> <span class="token keyword">STORED</span><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
Stored but not virtual generated columns can be altered to
nongenerated columns. The stored generated values become the
values of the nongenerated column.
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa19303787"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> t1 <span class="token punctuation">(</span>c1 <span class="token datatype">INT</span><span class="token punctuation">,</span> c2 <span class="token datatype">INT</span> <span class="token keyword">GENERATED</span> <span class="token keyword">ALWAYS</span> <span class="token keyword">AS</span> <span class="token punctuation">(</span>c1 <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">)</span> <span class="token keyword">STORED</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">ALTER</span> <span class="token keyword">TABLE</span> t1 <span class="token keyword">MODIFY</span> <span class="token keyword">COLUMN</span> c2 <span class="token datatype">INT</span><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
<code class="literal">
ADD COLUMN
</code>
is not an in-place operation
for stored columns (done without using a temporary table)
because the expression must be evaluated by the server. For
stored columns, indexing changes are done in place, and
expression changes are not done in place. Changes to column
comments are done in place.
</p>
</li>
<li class="listitem">
<p>
For non-partitioned tables,
<code class="literal">
ADD COLUMN
</code>
and
<code class="literal">
DROP COLUMN
</code>
are in-place operations
for virtual columns. However, adding or dropping a virtual
column cannot be performed in place in combination with
other
<a class="link" href="alter-table.html" title="15.1.9 ALTER TABLE Statement">
<code class="literal">
ALTER TABLE
</code>
</a>
operations.
</p>
<p>
For partitioned tables,
<code class="literal">
ADD COLUMN
</code>
and
<code class="literal">
DROP COLUMN
</code>
are not in-place operations
for virtual columns.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
InnoDB
</code>
supports secondary indexes on
virtual generated columns. Adding or dropping a secondary
index on a virtual generated column is an in-place
operation. For more information, see
<a class="xref" href="create-table-secondary-indexes.html" title="15.1.20.9 Secondary Indexes and Generated Columns">
Section 15.1.20.9, “Secondary Indexes and Generated Columns”
</a>
.
</p>
</li>
<li class="listitem">
<p>
When a
<code class="literal">
VIRTUAL
</code>
generated column is added
to a table or modified, it is not ensured that data being
calculated by the generated column expression is not out of
range for the column. This can lead to inconsistent data
being returned and unexpectedly failed statements. To permit
control over whether validation occurs for such columns,
<code class="literal">
ALTER TABLE
</code>
supports
<code class="literal">
WITHOUT
VALIDATION
</code>
and
<code class="literal">
WITH VALIDATION
</code>
clauses:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
With
<code class="literal">
WITHOUT VALIDATION
</code>
(the default
if neither clause is specified), an in-place operation
is performed (if possible), data integrity is not
checked, and the statement finishes more quickly.
However, later reads from the table might report
warnings or errors for the column if values are out of
range.
</p>
</li>
<li class="listitem">
<p>
With
<code class="literal">
WITH VALIDATION
</code>
,
<code class="literal">
ALTER
TABLE
</code>
copies the table. If an out-of-range or
any other error occurs, the statement fails. Because a
table copy is performed, the statement takes longer.
</p>
</li>
</ul>
</div>
<p>
<code class="literal">
WITHOUT VALIDATION
</code>
and
<code class="literal">
WITH
VALIDATION
</code>
are permitted only with
<code class="literal">
ADD
COLUMN
</code>
,
<code class="literal">
CHANGE COLUMN
</code>
, and
<code class="literal">
MODIFY COLUMN
</code>
operations. Otherwise, an
<a class="ulink" href="/doc/mysql-errors/8.4/en/server-error-reference.html#error_er_wrong_usage" target="_top">
<code class="literal">
ER_WRONG_USAGE
</code>
</a>
error occurs.
</p>
</li>
<li class="listitem">
<p>
If expression evaluation causes truncation or provides
incorrect input to a function, the
<a class="link" href="alter-table.html" title="15.1.9 ALTER TABLE Statement">
<code class="literal">
ALTER TABLE
</code>
</a>
statement
terminates with an error and the DDL operation is rejected.
</p>
</li>
<li class="listitem">
<p>
An
<a class="link" href="alter-table.html" title="15.1.9 ALTER TABLE Statement">
<code class="literal">
ALTER TABLE
</code>
</a>
statement that
changes the default value of a column
<em class="replaceable">
<code>
col_name
</code>
</em>
may also change the
value of a generated column expression that refers to the
column using
<em class="replaceable">
<code>
col_name
</code>
</em>
, which may
change the value of a generated column expression that
refers to the column using
<a class="link" href="miscellaneous-functions.html#function_default">
<code class="literal">
DEFAULT(
<em class="replaceable">
<code>
col_name
</code>
</em>
)
</code>
</a>
.
For this reason,
<a class="link" href="alter-table.html" title="15.1.9 ALTER TABLE Statement">
<code class="literal">
ALTER TABLE
</code>
</a>
operations that change the definition of a column cause a
table rebuild if any generated column expression uses
<a class="link" href="miscellaneous-functions.html#function_default">
<code class="literal">
DEFAULT()
</code>
</a>
.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/ansi-diff-comments.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="ansi-diff-comments">
</a>
1.7.2.4 '--' as the Start of a Comment
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045333175952">
</a>
<a class="indexterm" name="idm46045333174496">
</a>
<p>
Standard SQL uses the C syntax
<code class="literal">
/* this is a comment
*/
</code>
for comments, and MySQL Server supports this
syntax as well. MySQL also support extensions to this syntax
that enable MySQL-specific SQL to be embedded in the comment;
see
<a class="xref" href="comments.html" title="11.7 Comments">
Section 11.7, “Comments”
</a>
.
</p>
<p>
MySQL Server also uses
<code class="literal">
#
</code>
as the start
comment character. This is nonstandard.
</p>
<p>
Standard SQL also uses
<span class="quote">
“
<span class="quote">
<code class="option">
--
</code>
</span>
”
</span>
as a
start-comment sequence. MySQL Server supports a variant of the
<code class="literal">
--
</code>
comment style; the
<code class="literal">
--
</code>
start-comment sequence is accepted as such, but must be
followed by a whitespace character such as a space or newline.
The space is intended to prevent problems with generated SQL
queries that use constructs such as the following, which
updates the balance to reflect a charge:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa6123982"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> <span class="token keyword">account</span> <span class="token keyword">SET</span> balance<span class="token operator">=</span>balance<span class="token operator">-</span>charge
<span class="token keyword">WHERE</span> account_id<span class="token operator">=</span>user_id</code></pre>
</div>
<p>
Consider what happens when
<code class="literal">
charge
</code>
has a
negative value such as
<code class="literal">
-1
</code>
, which might be
the case when an amount is credited to the account. In this
case, the generated statement looks like this:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa41148760"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> <span class="token keyword">account</span> <span class="token keyword">SET</span> balance<span class="token operator">=</span>balance<span class="token comment" spellcheck="true">--1</span>
<span class="token keyword">WHERE</span> account_id<span class="token operator">=</span><span class="token number">5752</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
<code class="literal">
balance--1
</code>
is valid standard SQL, but
<code class="literal">
--
</code>
is interpreted as the start of a
comment, and part of the expression is discarded. The result
is a statement that has a completely different meaning than
intended:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa26420572"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> <span class="token keyword">account</span> <span class="token keyword">SET</span> balance<span class="token operator">=</span>balance
<span class="token keyword">WHERE</span> account_id<span class="token operator">=</span><span class="token number">5752</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
This statement produces no change in value at all. To keep
this from happening, MySQL requires a whitespace character
following the
<code class="literal">
--
</code>
for it to be recognized as
a start-comment sequence in MySQL Server, so that an
expression such as
<code class="literal">
balance--1
</code>
is always
safe to use.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/replica-logs-relaylog.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="replica-logs-relaylog">
</a>
19.2.4.1 The Relay Log
</h4>
</div>
</div>
</div>
<p>
The relay log, like the binary log, consists of a set of
numbered files containing events that describe database changes,
and an index file that contains the names of all used relay log
files. The default location for relay log files is the data
directory.
</p>
<p>
The term
<span class="quote">
“
<span class="quote">
relay log file
</span>
”
</span>
generally denotes an
individual numbered file containing database events. The term
<span class="quote">
“
<span class="quote">
relay log
</span>
”
</span>
collectively denotes the set of
numbered relay log files plus the index file.
</p>
<p>
Relay log files have the same format as binary log files and can
be read using
<a class="link" href="mysqlbinlog.html" title="6.6.9 mysqlbinlog — Utility for Processing Binary Log Files">
<span class="command">
<strong>
mysqlbinlog
</strong>
</span>
</a>
(see
<a class="xref" href="mysqlbinlog.html" title="6.6.9 mysqlbinlog — Utility for Processing Binary Log Files">
Section 6.6.9, “mysqlbinlog — Utility for Processing Binary Log Files”
</a>
). If binary log transaction
compression is in use, transaction payloads written to the relay
log are compressed in the same way as for the binary log. For
more information on binary log transaction compression, see
<a class="xref" href="binary-log-transaction-compression.html" title="7.4.4.5 Binary Log Transaction Compression">
Section 7.4.4.5, “Binary Log Transaction Compression”
</a>
.
</p>
<p>
For the default replication channel, relay log file names have
the default form
<code class="filename">
<em class="replaceable">
<code>
host_name
</code>
</em>
-relay-bin.
<em class="replaceable">
<code>
nnnnnn
</code>
</em>
</code>
,
where
<em class="replaceable">
<code>
host_name
</code>
</em>
is the name of the
replica server host and
<em class="replaceable">
<code>
nnnnnn
</code>
</em>
is a
sequence number. Successive relay log files are created using
successive sequence numbers, beginning with
<code class="literal">
000001
</code>
. For non-default replication channels,
the default base name is
<code class="filename">
<em class="replaceable">
<code>
host_name
</code>
</em>
-relay-bin-
<em class="replaceable">
<code>
channel
</code>
</em>
</code>
,
where
<em class="replaceable">
<code>
channel
</code>
</em>
is the name of the
replication channel recorded in the relay log.
</p>
<p>
The replica uses an index file to track the relay log files
currently in use. The default relay log index file name is
<code class="filename">
<em class="replaceable">
<code>
host_name
</code>
</em>
-relay-bin.index
</code>
for the default channel, and
<code class="filename">
<em class="replaceable">
<code>
host_name
</code>
</em>
-relay-bin-
<em class="replaceable">
<code>
channel
</code>
</em>
.index
</code>
for non-default replication channels.
</p>
<p>
The default relay log file and relay log index file names and
locations can be overridden with, respectively, the
<a class="link" href="replication-options-replica.html#sysvar_relay_log">
<code class="literal">
relay_log
</code>
</a>
and
<a class="link" href="replication-options-replica.html#sysvar_relay_log_index">
<code class="literal">
relay_log_index
</code>
</a>
system
variables (see
<a class="xref" href="replication-options.html" title="19.1.6 Replication and Binary Logging Options and Variables">
Section 19.1.6, “Replication and Binary Logging Options and Variables”
</a>
).
</p>
<p>
If a replica uses the default host-based relay log file names,
changing a replica's host name after replication has been set up
can cause replication to fail with the errors
<span class="errortext">
Failed
to open the relay log
</span>
and
<span class="errortext">
Could not find
target log during relay log initialization
</span>
. This is
a known issue (see Bug #2122). If you anticipate that a
replica's host name might change in the future (for example, if
networking is set up on the replica such that its host name can
be modified using DHCP), you can avoid this issue entirely by
using the
<a class="link" href="replication-options-replica.html#sysvar_relay_log">
<code class="literal">
relay_log
</code>
</a>
and
<a class="link" href="replication-options-replica.html#sysvar_relay_log_index">
<code class="literal">
relay_log_index
</code>
</a>
system
variables to specify relay log file names explicitly when you
initially set up the replica. This causes the names to be
independent of server host name changes.
</p>
<p>
If you encounter the issue after replication has already begun,
one way to work around it is to stop the replica server, prepend
the contents of the old relay log index file to the new one, and
then restart the replica. On a Unix system, this can be done as
shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-terminal"><div class="docs-select-all right" id="sa39275147"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token prompt">$> </span><span class="token command">cat</span> <em class="replaceable">new_relay_log_name</em><span class="token punctuation">.</span>index >> <em class="replaceable">old_relay_log_name</em><span class="token punctuation">.</span>index
<span class="token prompt">$> </span><span class="token command">mv</span> <em class="replaceable">old_relay_log_name</em><span class="token punctuation">.</span>index <em class="replaceable">new_relay_log_name</em><span class="token punctuation">.</span>index</code></pre>
</div>
<p>
A replica server creates a new relay log file under the
following conditions:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Each time the replication I/O (receiver) thread starts.
</p>
</li>
<li class="listitem">
<p>
When the logs are flushed (for example, with
<a class="link" href="flush.html#flush-logs">
<code class="literal">
FLUSH LOGS
</code>
</a>
or
<a class="link" href="mysqladmin.html" title="6.5.2 mysqladmin — A MySQL Server Administration Program">
<span class="command">
<strong>
mysqladmin flush-logs
</strong>
</span>
</a>
).
</p>
</li>
<li class="listitem">
<p>
When the size of the current relay log file becomes too
large, which is determined as follows:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
If the value of
<a class="link" href="replication-options-replica.html#sysvar_max_relay_log_size">
<code class="literal">
max_relay_log_size
</code>
</a>
is
greater than 0, that is the maximum relay log file size.
</p>
</li>
<li class="listitem">
<p>
If the value of
<a class="link" href="replication-options-replica.html#sysvar_max_relay_log_size">
<code class="literal">
max_relay_log_size
</code>
</a>
is
0,
<a class="link" href="replication-options-binary-log.html#sysvar_max_binlog_size">
<code class="literal">
max_binlog_size
</code>
</a>
determines the maximum relay log file size.
</p>
</li>
</ul>
</div>
</li>
</ul>
</div>
<p>
The replication SQL (applier) thread automatically deletes each
relay log file after it has executed all events in the file and
no longer needs it. There is no explicit mechanism for deleting
relay logs because the replication SQL thread takes care of
doing so. However,
<a class="link" href="flush.html#flush-logs">
<code class="literal">
FLUSH LOGS
</code>
</a>
rotates relay logs, which influences when the replication SQL
thread deletes them.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/update.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="update">
</a>
15.2.17 UPDATE Statement
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045179481888">
</a>
<a class="indexterm" name="idm46045179480816">
</a>
<p>
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
is a DML statement that
modifies rows in a table.
</p>
<p>
An
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
statement can start with
a
<a class="link" href="with.html" title="15.2.20 WITH (Common Table Expressions)">
<code class="literal">
WITH
</code>
</a>
clause to define common
table expressions accessible within the
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
. See
<a class="xref" href="with.html" title="15.2.20 WITH (Common Table Expressions)">
Section 15.2.20, “WITH (Common Table Expressions)”
</a>
.
</p>
<p>
Single-table syntax:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa23652254"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> <span class="token punctuation">[</span><span class="token keyword">LOW_PRIORITY</span><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">IGNORE</span><span class="token punctuation">]</span> <em class="replaceable">table_reference</em>
<span class="token keyword">SET</span> <em class="replaceable">assignment_list</em>
<span class="token punctuation">[</span><span class="token keyword">WHERE</span> <em class="replaceable">where_condition</em><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">LIMIT</span> <span class="token keyword"><em class="replaceable">row_count</em></span><span class="token punctuation">]</span>
<span class="token keyword"><em class="replaceable">value</em></span>:
{<em class="replaceable">expr</em> <span class="token operator">|</span> <span class="token keyword">DEFAULT</span>}
<em class="replaceable">assignment</em>:
<em class="replaceable">col_name</em> <span class="token operator">=</span> <span class="token keyword"><em class="replaceable">value</em></span>
<em class="replaceable">assignment_list</em>:
<em class="replaceable">assignment</em> <span class="token punctuation">[</span><span class="token punctuation">,</span> <em class="replaceable">assignment</em><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span></code></pre>
</div>
<p>
Multiple-table syntax:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa17412624"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> <span class="token punctuation">[</span><span class="token keyword">LOW_PRIORITY</span><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">IGNORE</span><span class="token punctuation">]</span> <em class="replaceable">table_references</em>
<span class="token keyword">SET</span> <em class="replaceable">assignment_list</em>
<span class="token punctuation">[</span><span class="token keyword">WHERE</span> <em class="replaceable">where_condition</em><span class="token punctuation">]</span></code></pre>
</div>
<p>
For the single-table syntax, the
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
statement updates columns of
existing rows in the named table with new values. The
<code class="literal">
SET
</code>
clause indicates which columns to modify
and the values they should be given. Each value can be given as an
expression, or the keyword
<code class="literal">
DEFAULT
</code>
to set a
column explicitly to its default value. The
<code class="literal">
WHERE
</code>
clause, if given, specifies the
conditions that identify which rows to update. With no
<code class="literal">
WHERE
</code>
clause, all rows are updated. If the
<code class="literal">
ORDER BY
</code>
clause is specified, the rows are
updated in the order that is specified. The
<code class="literal">
LIMIT
</code>
clause places a limit on the number of
rows that can be updated.
</p>
<p>
For the multiple-table syntax,
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
updates rows in each table
named in
<em class="replaceable">
<code>
table_references
</code>
</em>
that satisfy
the conditions. Each matching row is updated once, even if it
matches the conditions multiple times. For multiple-table syntax,
<code class="literal">
ORDER BY
</code>
and
<code class="literal">
LIMIT
</code>
cannot be
used.
</p>
<p>
For partitioned tables, both the single-single and multiple-table
forms of this statement support the use of a
<code class="literal">
PARTITION
</code>
clause as part of a table reference.
This option takes a list of one or more partitions or
subpartitions (or both). Only the partitions (or subpartitions)
listed are checked for matches, and a row that is not in any of
these partitions or subpartitions is not updated, whether it
satisfies the
<em class="replaceable">
<code>
where_condition
</code>
</em>
or not.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
Unlike the case when using
<code class="literal">
PARTITION
</code>
with an
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
or
<a class="link" href="replace.html" title="15.2.12 REPLACE Statement">
<code class="literal">
REPLACE
</code>
</a>
statement, an otherwise
valid
<code class="literal">
UPDATE ... PARTITION
</code>
statement is
considered successful even if no rows in the listed partitions
(or subpartitions) match the
<em class="replaceable">
<code>
where_condition
</code>
</em>
.
</p>
</div>
<p>
For more information and examples, see
<a class="xref" href="partitioning-selection.html" title="26.5 Partition Selection">
Section 26.5, “Partition Selection”
</a>
.
</p>
<p>
<em class="replaceable">
<code>
where_condition
</code>
</em>
is an expression that
evaluates to true for each row to be updated. For expression
syntax, see
<a class="xref" href="expressions.html" title="11.5 Expressions">
Section 11.5, “Expressions”
</a>
.
</p>
<p>
<em class="replaceable">
<code>
table_references
</code>
</em>
and
<em class="replaceable">
<code>
where_condition
</code>
</em>
are specified as
described in
<a class="xref" href="select.html" title="15.2.13 SELECT Statement">
Section 15.2.13, “SELECT Statement”
</a>
.
</p>
<p>
You need the
<a class="link" href="privileges-provided.html#priv_update">
<code class="literal">
UPDATE
</code>
</a>
privilege only
for columns referenced in an
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
that are actually updated. You need only the
<a class="link" href="privileges-provided.html#priv_select">
<code class="literal">
SELECT
</code>
</a>
privilege for any columns
that are read but not modified.
</p>
<p>
The
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
statement supports the
following modifiers:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
With the
<code class="literal">
LOW_PRIORITY
</code>
modifier, execution
of the
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
is delayed until
no other clients are reading from the table. This affects only
storage engines that use only table-level locking (such as
<code class="literal">
MyISAM
</code>
,
<code class="literal">
MEMORY
</code>
, and
<code class="literal">
MERGE
</code>
).
</p>
<a class="indexterm" name="idm46045179427024">
</a>
</li>
<li class="listitem">
<p>
With the
<code class="literal">
IGNORE
</code>
modifier, the update
statement does not abort even if errors occur during the
update. Rows for which duplicate-key conflicts occur on a
unique key value are not updated. Rows updated to values that
would cause data conversion errors are updated to the closest
valid values instead. For more information, see
<a class="xref" href="sql-mode.html#ignore-effect-on-execution" title="The Effect of IGNORE on Statement Execution">
The Effect of IGNORE on Statement Execution
</a>
.
</p>
<a class="indexterm" name="idm46045179422912">
</a>
</li>
</ul>
</div>
<p>
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE IGNORE
</code>
</a>
statements, including those having an
<code class="literal">
ORDER BY
</code>
clause, are flagged as unsafe for statement-based replication.
(This is because the order in which the rows are updated
determines which rows are ignored.) Such statements produce a
warning in the error log when using statement-based mode and are
written to the binary log using the row-based format when using
<code class="literal">
MIXED
</code>
mode. (Bug #11758262, Bug #50439) See
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
, for more
information.
</p>
<p>
If you access a column from the table to be updated in an
expression,
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
uses the current
value of the column. For example, the following statement sets
<code class="literal">
col1
</code>
to one more than its current value:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa12736371"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> t1 <span class="token keyword">SET</span> col1 <span class="token operator">=</span> col1 <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
The second assignment in the following statement sets
<code class="literal">
col2
</code>
to the current (updated)
<code class="literal">
col1
</code>
value, not the original
<code class="literal">
col1
</code>
value. The result is that
<code class="literal">
col1
</code>
and
<code class="literal">
col2
</code>
have the same
value. This behavior differs from standard SQL.
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa39125984"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> t1 <span class="token keyword">SET</span> col1 <span class="token operator">=</span> col1 <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">,</span> col2 <span class="token operator">=</span> col1<span class="token punctuation">;</span></code></pre>
</div>
<p>
Single-table
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
assignments are
generally evaluated from left to right. For multiple-table
updates, there is no guarantee that assignments are carried out in
any particular order.
</p>
<p>
If you set a column to the value it currently has, MySQL notices
this and does not update it.
</p>
<p>
If you update a column that has been declared
<code class="literal">
NOT
NULL
</code>
by setting to
<code class="literal">
NULL
</code>
, an error
occurs if strict SQL mode is enabled; otherwise, the column is set
to the implicit default value for the column data type and the
warning count is incremented. The implicit default value is
<code class="literal">
0
</code>
for numeric types, the empty string
(
<code class="literal">
''
</code>
) for string types, and the
<span class="quote">
“
<span class="quote">
zero
</span>
”
</span>
value for date and time types. See
<a class="xref" href="data-type-defaults.html" title="13.6 Data Type Default Values">
Section 13.6, “Data Type Default Values”
</a>
.
</p>
<a class="indexterm" name="idm46045179400704">
</a>
<p>
If a generated column is updated explicitly, the only permitted
value is
<code class="literal">
DEFAULT
</code>
. For information about
generated columns, see
<a class="xref" href="create-table-generated-columns.html" title="15.1.20.8 CREATE TABLE and Generated Columns">
Section 15.1.20.8, “CREATE TABLE and Generated Columns”
</a>
.
</p>
<a class="indexterm" name="idm46045179397216">
</a>
<p>
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
returns the number of rows
that were actually changed. The
<a class="ulink" href="/doc/c-api/8.4/en/mysql-info.html" target="_top">
<code class="literal">
mysql_info()
</code>
</a>
C API function
returns the number of rows that were matched and updated and the
number of warnings that occurred during the
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
.
</p>
<p>
You can use
<code class="literal">
LIMIT
<em class="replaceable">
<code>
row_count
</code>
</em>
</code>
to restrict the
scope of the
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
. A
<code class="literal">
LIMIT
</code>
clause is a rows-matched restriction. The
statement stops as soon as it has found
<em class="replaceable">
<code>
row_count
</code>
</em>
rows that satisfy the
<code class="literal">
WHERE
</code>
clause, whether or not they actually were
changed.
</p>
<p>
If an
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
statement includes an
<code class="literal">
ORDER BY
</code>
clause, the rows are updated in the
order specified by the clause. This can be useful in certain
situations that might otherwise result in an error. Suppose that a
table
<code class="literal">
t
</code>
contains a column
<code class="literal">
id
</code>
that has a unique index. The following statement could fail with a
duplicate-key error, depending on the order in which rows are
updated:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa9328405"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> t <span class="token keyword">SET</span> id <span class="token operator">=</span> id <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
For example, if the table contains 1 and 2 in the
<code class="literal">
id
</code>
column and 1 is updated to 2 before 2 is
updated to 3, an error occurs. To avoid this problem, add an
<code class="literal">
ORDER BY
</code>
clause to cause the rows with larger
<code class="literal">
id
</code>
values to be updated before those with
smaller values:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa95910675"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> t <span class="token keyword">SET</span> id <span class="token operator">=</span> id <span class="token operator">+</span> <span class="token number">1</span> <span class="token keyword">ORDER</span> <span class="token keyword">BY</span> id <span class="token keyword">DESC</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
You can also perform
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
operations covering multiple tables. However, you cannot use
<code class="literal">
ORDER BY
</code>
or
<code class="literal">
LIMIT
</code>
with a
multiple-table
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
. The
<em class="replaceable">
<code>
table_references
</code>
</em>
clause lists the
tables involved in the join. Its syntax is described in
<a class="xref" href="join.html" title="15.2.13.2 JOIN Clause">
Section 15.2.13.2, “JOIN Clause”
</a>
. Here is an example:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa99134233"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> items<span class="token punctuation">,</span><span class="token keyword">month</span> <span class="token keyword">SET</span> items<span class="token punctuation">.</span>price<span class="token operator">=</span><span class="token keyword">month</span><span class="token punctuation">.</span>price
<span class="token keyword">WHERE</span> items<span class="token punctuation">.</span>id<span class="token operator">=</span><span class="token keyword">month</span><span class="token punctuation">.</span>id<span class="token punctuation">;</span></code></pre>
</div>
<p>
The preceding example shows an inner join that uses the comma
operator, but multiple-table
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
statements can use any type of join permitted in
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
statements, such as
<code class="literal">
LEFT JOIN
</code>
.
</p>
<p>
If you use a multiple-table
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
statement involving
<code class="literal">
InnoDB
</code>
tables for which
there are foreign key constraints, the MySQL optimizer might
process tables in an order that differs from that of their
parent/child relationship. In this case, the statement fails and
rolls back. Instead, update a single table and rely on the
<code class="literal">
ON UPDATE
</code>
capabilities that
<code class="literal">
InnoDB
</code>
provides to cause the other tables to be
modified accordingly. See
<a class="xref" href="create-table-foreign-keys.html" title="15.1.20.5 FOREIGN KEY Constraints">
Section 15.1.20.5, “FOREIGN KEY Constraints”
</a>
.
</p>
<p>
You cannot update a table and select directly from the same table
in a subquery. You can work around this by using a multi-table
update in which one of the tables is derived from the table that
you actually wish to update, and referring to the derived table
using an alias. Suppose you wish to update a table named
<code class="literal">
items
</code>
which is defined using the statement
shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa75670693"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> items <span class="token punctuation">(</span>
id <span class="token datatype">BIGINT</span> <span class="token operator">NOT</span> <span class="token boolean">NULL</span> <span class="token keyword">AUTO_INCREMENT</span> <span class="token keyword">PRIMARY</span> <span class="token keyword">KEY</span><span class="token punctuation">,</span>
wholesale <span class="token datatype">DECIMAL</span><span class="token punctuation">(</span><span class="token number">6</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">)</span> <span class="token operator">NOT</span> <span class="token boolean">NULL</span> <span class="token keyword">DEFAULT</span> <span class="token number">0.00</span><span class="token punctuation">,</span>
retail <span class="token datatype">DECIMAL</span><span class="token punctuation">(</span><span class="token number">6</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">)</span> <span class="token operator">NOT</span> <span class="token boolean">NULL</span> <span class="token keyword">DEFAULT</span> <span class="token number">0.00</span><span class="token punctuation">,</span>
quantity <span class="token datatype">BIGINT</span> <span class="token operator">NOT</span> <span class="token boolean">NULL</span> <span class="token keyword">DEFAULT</span> <span class="token number">0</span>
<span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
To reduce the retail price of any items for which the markup is
30% or greater and of which you have fewer than one hundred in
stock, you might try to use an
<code class="literal">
UPDATE
</code>
statement
such as the one following, which uses a subquery in the
<code class="literal">
WHERE
</code>
clause. As shown here, this statement
does not work:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa17842628"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">UPDATE</span> items
<span class="token operator">></span> <span class="token keyword">SET</span> retail <span class="token operator">=</span> retail <span class="token operator">*</span> <span class="token number">0.9</span>
<span class="token operator">></span> <span class="token keyword">WHERE</span> id <span class="token keyword">IN</span>
<span class="token operator">></span> <span class="token punctuation">(</span><span class="token keyword">SELECT</span> id <span class="token keyword">FROM</span> items
<span class="token operator">></span> <span class="token keyword">WHERE</span> retail <span class="token operator">/</span> wholesale <span class="token operator">>=</span> <span class="token number">1.3</span> <span class="token operator">AND</span> quantity <span class="token operator">></span> <span class="token number">100</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output">ERROR 1093 (HY000)<span class="token punctuation">:</span> You can't specify target table 'items' for update in FROM clause</span></code></pre>
</div>
<p>
Instead, you can employ a multi-table update in which the subquery
is moved into the list of tables to be updated, using an alias to
reference it in the outermost
<code class="literal">
WHERE
</code>
clause,
like this:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa89259935"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> items<span class="token punctuation">,</span>
<span class="token punctuation">(</span><span class="token keyword">SELECT</span> id <span class="token keyword">FROM</span> items
<span class="token keyword">WHERE</span> id <span class="token keyword">IN</span>
<span class="token punctuation">(</span><span class="token keyword">SELECT</span> id <span class="token keyword">FROM</span> items
<span class="token keyword">WHERE</span> retail <span class="token operator">/</span> wholesale <span class="token operator">>=</span> <span class="token number">1.3</span> <span class="token operator">AND</span> quantity <span class="token operator"><</span> <span class="token number">100</span><span class="token punctuation">)</span><span class="token punctuation">)</span>
<span class="token keyword">AS</span> discounted
<span class="token keyword">SET</span> items<span class="token punctuation">.</span>retail <span class="token operator">=</span> items<span class="token punctuation">.</span>retail <span class="token operator">*</span> <span class="token number">0.9</span>
<span class="token keyword">WHERE</span> items<span class="token punctuation">.</span>id <span class="token operator">=</span> discounted<span class="token punctuation">.</span>id<span class="token punctuation">;</span></code></pre>
</div>
<p>
Because the optimizer tries by default to merge the derived table
<code class="literal">
discounted
</code>
into the outermost query block, this
works only if you force materialization of the derived table. You
can do this by setting the
<a class="link" href="switchable-optimizations.html#optflag_derived-merge">
<code class="literal">
derived_merge
</code>
</a>
flag of the
<a class="link" href="server-system-variables.html#sysvar_optimizer_switch">
<code class="literal">
optimizer_switch
</code>
</a>
system variable
to
<code class="literal">
off
</code>
before running the update, or by using
the
<a class="link" href="optimizer-hints.html#optimizer-hints-table-level" title="Table-Level Optimizer Hints">
<code class="literal">
NO_MERGE
</code>
</a>
optimizer hint, as
shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa40143224"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> <span class="token comment" spellcheck="true">/*+ NO_MERGE(discounted) */</span> items<span class="token punctuation">,</span>
<span class="token punctuation">(</span><span class="token keyword">SELECT</span> id <span class="token keyword">FROM</span> items
<span class="token keyword">WHERE</span> retail <span class="token operator">/</span> wholesale <span class="token operator">>=</span> <span class="token number">1.3</span> <span class="token operator">AND</span> quantity <span class="token operator"><</span> <span class="token number">100</span><span class="token punctuation">)</span>
<span class="token keyword">AS</span> discounted
<span class="token keyword">SET</span> items<span class="token punctuation">.</span>retail <span class="token operator">=</span> items<span class="token punctuation">.</span>retail <span class="token operator">*</span> <span class="token number">0.9</span>
<span class="token keyword">WHERE</span> items<span class="token punctuation">.</span>id <span class="token operator">=</span> discounted<span class="token punctuation">.</span>id<span class="token punctuation">;</span></code></pre>
</div>
<p>
The advantage of using the optimizer hint in such a case is that
it applies only within the query block where it is used, so that
it is not necessary to change the value of
<code class="literal">
optimizer_switch
</code>
again after executing the
<code class="literal">
UPDATE
</code>
.
</p>
<p>
Another possibility is to rewrite the subquery so that it does not
use
<code class="literal">
IN
</code>
or
<code class="literal">
EXISTS
</code>
, like this:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa1362092"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> items<span class="token punctuation">,</span>
<span class="token punctuation">(</span><span class="token keyword">SELECT</span> id<span class="token punctuation">,</span> retail <span class="token operator">/</span> wholesale <span class="token keyword">AS</span> markup<span class="token punctuation">,</span> quantity <span class="token keyword">FROM</span> items<span class="token punctuation">)</span>
<span class="token keyword">AS</span> discounted
<span class="token keyword">SET</span> items<span class="token punctuation">.</span>retail <span class="token operator">=</span> items<span class="token punctuation">.</span>retail <span class="token operator">*</span> <span class="token number">0.9</span>
<span class="token keyword">WHERE</span> discounted<span class="token punctuation">.</span>markup <span class="token operator">>=</span> <span class="token number">1.3</span>
<span class="token operator">AND</span> discounted<span class="token punctuation">.</span>quantity <span class="token operator"><</span> <span class="token number">100</span>
<span class="token operator">AND</span> items<span class="token punctuation">.</span>id <span class="token operator">=</span> discounted<span class="token punctuation">.</span>id<span class="token punctuation">;</span></code></pre>
</div>
<p>
In this case, the subquery is materialized by default rather than
merged, so it is not necessary to disable merging of the derived
table.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-programs-ndb-delete-all.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="mysql-cluster-programs-ndb-delete-all">
</a>
25.5.8 ndb_delete_all — Delete All Rows from an NDB Table
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045104744240">
</a>
<p>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html" title="25.5.8 ndb_delete_all — Delete All Rows from an NDB Table">
<span class="command">
<strong>
ndb_delete_all
</strong>
</span>
</a>
deletes all rows from the
given
<a class="link" href="mysql-cluster.html" title="Chapter 25 MySQL NDB Cluster 8.4">
<code class="literal">
NDB
</code>
</a>
table. In some cases,
this can be much faster than
<a class="link" href="delete.html" title="15.2.2 DELETE Statement">
<code class="literal">
DELETE
</code>
</a>
or even
<a class="link" href="truncate-table.html" title="15.1.37 TRUNCATE TABLE Statement">
<code class="literal">
TRUNCATE TABLE
</code>
</a>
.
</p>
<h4>
<a name="idm46045104737760">
</a>
Usage
</h4>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa56434088"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal">ndb_delete_all <span class="token property">-c</span> <em class="replaceable">connection_string</em> <em class="replaceable">tbl_name</em> <span class="token property">-d</span> <em class="replaceable">db_name</em></code></pre>
</div>
<p>
This deletes all rows from the table named
<em class="replaceable">
<code>
tbl_name
</code>
</em>
in the database named
<em class="replaceable">
<code>
db_name
</code>
</em>
. It is exactly equivalent to
executing
<code class="literal">
TRUNCATE
<em class="replaceable">
<code>
db_name
</code>
</em>
.
<em class="replaceable">
<code>
tbl_name
</code>
</em>
</code>
in MySQL.
</p>
<p>
Options that can be used with
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html" title="25.5.8 ndb_delete_all — Delete All Rows from an NDB Table">
<span class="command">
<strong>
ndb_delete_all
</strong>
</span>
</a>
are shown in the following table. Additional descriptions follow
the table.
</p>
<p>
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a name="option_ndb_delete_all_character-sets-dir">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_character-sets-dir">
<code class="option">
--character-sets-dir
</code>
</a>
</p>
<a class="indexterm" name="idm46045104727088">
</a>
<a class="indexterm" name="idm46045104725584">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for character-sets-dir">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--character-sets-dir=path
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Directory containing character sets.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_connect-retries">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_connect-retries">
<code class="option">
--connect-retries
</code>
</a>
</p>
<a class="indexterm" name="idm46045104715792">
</a>
<a class="indexterm" name="idm46045104714304">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for connect-retries">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--connect-retries=#
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
12
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
<tr>
<th>
Maximum Value
</th>
<td>
<code class="literal">
12
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Number of times to retry connection before giving up.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_connect-retry-delay">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_connect-retry-delay">
<code class="option">
--connect-retry-delay
</code>
</a>
</p>
<a class="indexterm" name="idm46045104695136">
</a>
<a class="indexterm" name="idm46045104693632">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for connect-retry-delay">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--connect-retry-delay=#
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
5
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
<tr>
<th>
Maximum Value
</th>
<td>
<code class="literal">
5
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Number of seconds to wait between attempts to contact
management server.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_connect-string">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_connect-string">
<code class="option">
--connect-string
</code>
</a>
</p>
<a class="indexterm" name="idm46045104674576">
</a>
<a class="indexterm" name="idm46045104673088">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for connect-string">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--connect-string=connection_string
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Same as
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_ndb-connectstring">
<code class="option">
--ndb-connectstring
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_core-file">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_core-file">
<code class="option">
--core-file
</code>
</a>
</p>
<a class="indexterm" name="idm46045104657728">
</a>
<a class="indexterm" name="idm46045104656240">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for core-file">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--core-file
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Write core file on error; used in debugging.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_database">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_database">
<code class="option">
--database
</code>
</a>
,
<code class="option">
-d
</code>
</p>
<a class="indexterm" name="idm46045104646112">
</a>
<a class="indexterm" name="idm46045104644624">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for database">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--database=name
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
TEST_DB
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Name of the database containing the table to delete from.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_defaults-extra-file">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_defaults-extra-file">
<code class="option">
--defaults-extra-file
</code>
</a>
</p>
<a class="indexterm" name="idm46045104630272">
</a>
<a class="indexterm" name="idm46045104628768">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for defaults-extra-file">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--defaults-extra-file=path
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Read given file after global files are read.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_defaults-file">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_defaults-file">
<code class="option">
--defaults-file
</code>
</a>
</p>
<a class="indexterm" name="idm46045104614544">
</a>
<a class="indexterm" name="idm46045104613056">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for defaults-file">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--defaults-file=path
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Read default options from given file only.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_defaults-group-suffix">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_defaults-group-suffix">
<code class="option">
--defaults-group-suffix
</code>
</a>
</p>
<a class="indexterm" name="idm46045104598768">
</a>
<a class="indexterm" name="idm46045104597264">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for defaults-group-suffix">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--defaults-group-suffix=string
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Also read groups with concat(group, suffix).
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_diskscan">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_diskscan">
<code class="option">
--diskscan
</code>
</a>
</p>
<a class="indexterm" name="idm46045104582976">
</a>
<a class="indexterm" name="idm46045104581488">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for diskscan">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--diskscan
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Run a disk scan.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_help">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_help">
<code class="option">
--help
</code>
</a>
</p>
<a class="indexterm" name="idm46045104571808">
</a>
<a class="indexterm" name="idm46045104570320">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for help">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--help
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Display help text and exit.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_login-path">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_login-path">
<code class="option">
--login-path
</code>
</a>
</p>
<a class="indexterm" name="idm46045104560512">
</a>
<a class="indexterm" name="idm46045104559024">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for login-path">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--login-path=path
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Read given path from login file.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_no-login-paths">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_no-login-paths">
<code class="option">
--no-login-paths
</code>
</a>
</p>
<a class="indexterm" name="idm46045104544816">
</a>
<a class="indexterm" name="idm46045104543328">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for no-login-paths">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--no-login-paths
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Skips reading options from the login path file.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_ndb-connectstring">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_ndb-connectstring">
<code class="option">
--ndb-connectstring
</code>
</a>
</p>
<a class="indexterm" name="idm46045104533728">
</a>
<a class="indexterm" name="idm46045104532272">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for ndb-connectstring">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--ndb-connectstring=connection_string
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Set connection string for connecting to
<a class="link" href="mysql-cluster-programs-ndb-mgmd.html" title="25.5.4 ndb_mgmd — The NDB Cluster Management Server Daemon">
<span class="command">
<strong>
ndb_mgmd
</strong>
</span>
</a>
. Syntax:
<code class="literal">
[nodeid=
<em class="replaceable">
<code>
id
</code>
</em>
;][host=]
<em class="replaceable">
<code>
hostname
</code>
</em>
[:
<em class="replaceable">
<code>
port
</code>
</em>
]
</code>
.
Overrides entries in
<code class="literal">
NDB_CONNECTSTRING
</code>
and
<code class="filename">
my.cnf
</code>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_ndb-mgm-tls">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_ndb-mgm-tls">
<code class="option">
--ndb-mgm-tls
</code>
</a>
</p>
<a class="indexterm" name="idm46045104513296">
</a>
<a class="indexterm" name="idm46045104511808">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for ndb-mgm-tls">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--ndb-mgm-tls=level
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Enumeration
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
relaxed
</code>
</td>
</tr>
<tr>
<th>
Valid Values
</th>
<td>
<p class="valid-value">
<code class="literal">
relaxed
</code>
</p>
<p class="valid-value">
<code class="literal">
strict
</code>
</p>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Sets the level of TLS support required to connect to the
management server; one of
<code class="literal">
relaxed
</code>
or
<code class="literal">
strict
</code>
.
<code class="literal">
relaxed
</code>
(the
default) means that a TLS connection is attempted, but
success is not required;
<code class="literal">
strict
</code>
means
that TLS is required to connect.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_ndb-mgmd-host">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_ndb-mgmd-host">
<code class="option">
--ndb-mgmd-host
</code>
</a>
</p>
<a class="indexterm" name="idm46045104490752">
</a>
<a class="indexterm" name="idm46045104489264">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for ndb-mgmd-host">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--ndb-mgmd-host=connection_string
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Same as
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_ndb-connectstring">
<code class="option">
--ndb-connectstring
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_ndb-nodeid">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_ndb-nodeid">
<code class="option">
--ndb-nodeid
</code>
</a>
</p>
<a class="indexterm" name="idm46045104474016">
</a>
<a class="indexterm" name="idm46045104472528">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for ndb-nodeid">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--ndb-nodeid=#
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Set node ID for this node, overriding any ID set by
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_ndb-connectstring">
<code class="option">
--ndb-connectstring
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_ndb-optimized-node-selection">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_ndb-optimized-node-selection">
<code class="option">
--ndb-optimized-node-selection
</code>
</a>
</p>
<a class="indexterm" name="idm46045104457152">
</a>
<a class="indexterm" name="idm46045104455648">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for ndb-optimized-node-selection">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--ndb-optimized-node-selection
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Enable optimizations for selection of nodes for
transactions. Enabled by default; use
<code class="option">
--skip-ndb-optimized-node-selection
</code>
to
disable.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_ndb-tls-search-path">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_ndb-tls-search-path">
<code class="option">
--ndb-tls-search-path
</code>
</a>
</p>
<a class="indexterm" name="idm46045104445216">
</a>
<a class="indexterm" name="idm46045104443712">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for ndb-tls-search-path">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--ndb-tls-search-path=list
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Path name
</td>
</tr>
<tr>
<th>
Default Value (Unix)
</th>
<td>
<code class="literal">
$HOME/ndb-tls
</code>
</td>
</tr>
<tr>
<th>
Default Value (Windows)
</th>
<td>
<code class="literal">
$HOMEDIR/ndb-tls
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Specify a list of directories to search for a CA file. On
Unix platforms, the directory names are separated by colons
(
<code class="literal">
:
</code>
); on Windows systems, the semicolon
character (
<code class="literal">
;
</code>
) is used as the separator. A
directory reference may be relative or absolute; it may
contain one or more environment variables, each denoted by a
prefixed dollar sign (
<code class="literal">
$
</code>
), and expanded
prior to use.
</p>
<p>
Searching begins with the leftmost named directory and
proceeds from left to right until a file is found. An empty
string denotes an empty search path, which causes all
searches to fail. A string consisting of a single dot
(
<code class="literal">
.
</code>
) indicates that the search path
limited to the current working directory.
</p>
<p>
If no search path is supplied, the compiled-in default value
is used. This value depends on the platform used: On
Windows, this is
<code class="literal">
\ndb-tls
</code>
; on other
platforms (including Linux), it is
<code class="literal">
$HOME/ndb-tls
</code>
. This can be overridden by
compiling NDB Cluster using
<a class="link" href="source-configuration-options.html#option_cmake_with_ndb_tls_search_path">
<code class="option">
-DWITH_NDB_TLS_SEARCH_PATH
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_no-defaults">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_no-defaults">
<code class="option">
--no-defaults
</code>
</a>
</p>
<a class="indexterm" name="idm46045104420016">
</a>
<a class="indexterm" name="idm46045104418528">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for no-defaults">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--no-defaults
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Do not read default options from any option file other than
login file.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_print-defaults">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_print-defaults">
<code class="option">
--print-defaults
</code>
</a>
</p>
<a class="indexterm" name="idm46045104408704">
</a>
<a class="indexterm" name="idm46045104407216">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for print-defaults">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--print-defaults
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Print program argument list and exit.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_transactional">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_transactional">
<code class="option">
--transactional
</code>
</a>
,
<code class="option">
-t
</code>
</p>
<a class="indexterm" name="idm46045104397024">
</a>
<a class="indexterm" name="idm46045104395536">
</a>
<p>
Use of this option causes the delete operation to be
performed as a single transaction.
</p>
<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Warning
</div>
<p>
With very large tables, using this option may cause the
number of operations available to the cluster to be
exceeded.
</p>
</div>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_tupscan">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_tupscan">
<code class="option">
--tupscan
</code>
</a>
</p>
<a class="indexterm" name="idm46045104390320">
</a>
<a class="indexterm" name="idm46045104388832">
</a>
<p>
Run a tuple scan.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_usage">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_usage">
<code class="option">
--usage
</code>
</a>
</p>
<a class="indexterm" name="idm46045104384656">
</a>
<a class="indexterm" name="idm46045104383168">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for usage">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--usage
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Display help text and exit; same as
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_help">
<code class="option">
--help
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_delete_all_version">
</a>
<a class="link" href="mysql-cluster-programs-ndb-delete-all.html#option_ndb_delete_all_version">
<code class="option">
--version
</code>
</a>
</p>
<a class="indexterm" name="idm46045104372480">
</a>
<a class="indexterm" name="idm46045104370992">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for version">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--version
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Display version information and exit.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/select.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="select">
</a>
15.2.13 SELECT Statement
</h3>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="select-into.html">
15.2.13.1 SELECT ... INTO Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="join.html">
15.2.13.2 JOIN Clause
</a>
</span>
</dt>
</dl>
</div>
<a class="indexterm" name="idm46045181044608">
</a>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa97027829"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span>
<span class="token punctuation">[</span><span class="token keyword">ALL</span> <span class="token operator">|</span> <span class="token keyword">DISTINCT</span> <span class="token operator">|</span> <span class="token keyword">DISTINCTROW</span> <span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">HIGH_PRIORITY</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">STRAIGHT_JOIN</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">SQL_SMALL_RESULT</span><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">SQL_BIG_RESULT</span><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">SQL_BUFFER_RESULT</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">SQL_NO_CACHE</span><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">SQL_CALC_FOUND_ROWS</span><span class="token punctuation">]</span>
<em class="replaceable">select_expr</em> <span class="token punctuation">[</span><span class="token punctuation">,</span> <em class="replaceable">select_expr</em><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span>
<span class="token punctuation">[</span><em class="replaceable">into_option</em><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">FROM</span> <em class="replaceable">table_references</em>
<span class="token punctuation">[</span><span class="token keyword">PARTITION</span> <em class="replaceable">partition_list</em><span class="token punctuation">]</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">WHERE</span> <em class="replaceable">where_condition</em><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">GROUP</span> <span class="token keyword">BY</span> {<em class="replaceable">col_name</em> <span class="token operator">|</span> <em class="replaceable">expr</em> <span class="token operator">|</span> <em class="replaceable">position</em>}<span class="token punctuation">,</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token punctuation">[</span><span class="token keyword">WITH</span> <span class="token keyword">ROLLUP</span><span class="token punctuation">]</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">HAVING</span> <em class="replaceable">where_condition</em><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">WINDOW</span> <em class="replaceable">window_name</em> <span class="token keyword">AS</span> <span class="token punctuation">(</span><em class="replaceable">window_spec</em><span class="token punctuation">)</span>
<span class="token punctuation">[</span><span class="token punctuation">,</span> <em class="replaceable">window_name</em> <span class="token keyword">AS</span> <span class="token punctuation">(</span><em class="replaceable">window_spec</em><span class="token punctuation">)</span><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">ORDER</span> <span class="token keyword">BY</span> {<em class="replaceable">col_name</em> <span class="token operator">|</span> <em class="replaceable">expr</em> <span class="token operator">|</span> <em class="replaceable">position</em>}
<span class="token punctuation">[</span><span class="token keyword">ASC</span> <span class="token operator">|</span> <span class="token keyword">DESC</span><span class="token punctuation">]</span><span class="token punctuation">,</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token punctuation">[</span><span class="token keyword">WITH</span> <span class="token keyword">ROLLUP</span><span class="token punctuation">]</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">LIMIT</span> {<span class="token punctuation">[</span><span class="token keyword"><em class="replaceable">offset</em></span><span class="token punctuation">,</span><span class="token punctuation">]</span> <span class="token keyword"><em class="replaceable">row_count</em></span> <span class="token operator">|</span> <span class="token keyword"><em class="replaceable">row_count</em></span> <span class="token keyword">OFFSET</span> <span class="token keyword"><em class="replaceable">offset</em></span>}<span class="token punctuation">]</span>
<span class="token punctuation">[</span><em class="replaceable">into_option</em><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">FOR</span> {<span class="token keyword">UPDATE</span> <span class="token operator">|</span> <span class="token keyword">SHARE</span>}
<span class="token punctuation">[</span><span class="token keyword">OF</span> <em class="replaceable">tbl_name</em> <span class="token punctuation">[</span><span class="token punctuation">,</span> <em class="replaceable">tbl_name</em><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">NOWAIT</span> <span class="token operator">|</span> <span class="token keyword">SKIP</span> <span class="token keyword">LOCKED</span><span class="token punctuation">]</span>
<span class="token operator">|</span> <span class="token keyword">LOCK</span> <span class="token keyword">IN</span> <span class="token keyword">SHARE</span> <span class="token keyword">MODE</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><em class="replaceable">into_option</em><span class="token punctuation">]</span>
<em class="replaceable">into_option</em>: {
<span class="token keyword">INTO</span> <span class="token keyword">OUTFILE</span> <span class="token string">'<em class="replaceable">file_name</em>'</span>
<span class="token punctuation">[</span><span class="token keyword">CHARACTER</span> <span class="token keyword">SET</span> <em class="replaceable">charset_name</em><span class="token punctuation">]</span>
<em class="replaceable">export_options</em>
<span class="token operator">|</span> <span class="token keyword">INTO</span> <span class="token keyword">DUMPFILE</span> <span class="token string">'<em class="replaceable">file_name</em>'</span>
<span class="token operator">|</span> <span class="token keyword">INTO</span> <em class="replaceable">var_name</em> <span class="token punctuation">[</span><span class="token punctuation">,</span> <em class="replaceable">var_name</em><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span>
}</code></pre>
</div>
<p>
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
is used to retrieve rows
selected from one or more tables, and can include
<a class="link" href="union.html" title="15.2.18 UNION Clause">
<code class="literal">
UNION
</code>
</a>
operations and subqueries.
<a class="link" href="intersect.html" title="15.2.8 INTERSECT Clause">
<code class="literal">
INTERSECT
</code>
</a>
and
<a class="link" href="except.html" title="15.2.4 EXCEPT Clause">
<code class="literal">
EXCEPT
</code>
</a>
operations are also
supported. The
<code class="literal">
UNION
</code>
,
<code class="literal">
INTERSECT
</code>
, and
<code class="literal">
EXCEPT
</code>
operators are described in more detail later in this section. See
also
<a class="xref" href="subqueries.html" title="15.2.15 Subqueries">
Section 15.2.15, “Subqueries”
</a>
.
</p>
<p>
A
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
statement can start with a
<a class="link" href="with.html" title="15.2.20 WITH (Common Table Expressions)">
<code class="literal">
WITH
</code>
</a>
clause to define common table
expressions accessible within the
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
. See
<a class="xref" href="with.html" title="15.2.20 WITH (Common Table Expressions)">
Section 15.2.20, “WITH (Common Table Expressions)”
</a>
.
</p>
<p>
The most commonly used clauses of
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
statements are these:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Each
<em class="replaceable">
<code>
select_expr
</code>
</em>
indicates a column
that you want to retrieve. There must be at least one
<em class="replaceable">
<code>
select_expr
</code>
</em>
.
</p>
</li>
<li class="listitem">
<p>
<em class="replaceable">
<code>
table_references
</code>
</em>
indicates the
table or tables from which to retrieve rows. Its syntax is
described in
<a class="xref" href="join.html" title="15.2.13.2 JOIN Clause">
Section 15.2.13.2, “JOIN Clause”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SELECT
</code>
supports explicit partition
selection using the
<code class="literal">
PARTITION
</code>
clause with a
list of partitions or subpartitions (or both) following the
name of the table in a
<em class="replaceable">
<code>
table_reference
</code>
</em>
(see
<a class="xref" href="join.html" title="15.2.13.2 JOIN Clause">
Section 15.2.13.2, “JOIN Clause”
</a>
). In this case, rows are selected only
from the partitions listed, and any other partitions of the
table are ignored. For more information and examples, see
<a class="xref" href="partitioning-selection.html" title="26.5 Partition Selection">
Section 26.5, “Partition Selection”
</a>
.
</p>
</li>
<li class="listitem">
<p>
The
<code class="literal">
WHERE
</code>
clause, if given, indicates the
condition or conditions that rows must satisfy to be selected.
<em class="replaceable">
<code>
where_condition
</code>
</em>
is an expression
that evaluates to true for each row to be selected. The
statement selects all rows if there is no
<code class="literal">
WHERE
</code>
clause.
</p>
<p>
In the
<code class="literal">
WHERE
</code>
expression, you can use any of
the functions and operators that MySQL supports, except for
aggregate (group) functions. See
<a class="xref" href="expressions.html" title="11.5 Expressions">
Section 11.5, “Expressions”
</a>
, and
<a class="xref" href="functions.html" title="Chapter 14 Functions and Operators">
Chapter 14,
<i>
Functions and Operators
</i>
</a>
.
</p>
</li>
</ul>
</div>
<p>
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
can also be used to retrieve
rows computed without reference to any table.
</p>
<p>
For example:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa80652143"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token number">1</span> <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">;</span>
<span class="token prompt"> -></span> <span class="token number">2</span></code></pre>
</div>
<p>
<a class="indexterm" name="idm46045180989136">
</a>
You are permitted to specify
<code class="literal">
DUAL
</code>
as a dummy
table name in situations where no tables are referenced:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa59583673"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token number">1</span> <span class="token operator">+</span> <span class="token number">1</span> <span class="token keyword">FROM</span> <span class="token keyword">DUAL</span><span class="token punctuation">;</span>
<span class="token prompt"> -></span> <span class="token number">2</span></code></pre>
</div>
<p>
<code class="literal">
DUAL
</code>
is purely for the convenience of people
who require that all
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
statements should have
<code class="literal">
FROM
</code>
and possibly other
clauses. MySQL may ignore the clauses. MySQL does not require
<code class="literal">
FROM DUAL
</code>
if no tables are referenced.
</p>
<p>
In general, clauses used must be given in exactly the order shown
in the syntax description. For example, a
<code class="literal">
HAVING
</code>
clause must come after any
<code class="literal">
GROUP BY
</code>
clause and before any
<code class="literal">
ORDER
BY
</code>
clause. The
<code class="literal">
INTO
</code>
clause, if
present, can appear in any position indicated by the syntax
description, but within a given statement can appear only once,
not in multiple positions. For more information about
<code class="literal">
INTO
</code>
, see
<a class="xref" href="select-into.html" title="15.2.13.1 SELECT ... INTO Statement">
Section 15.2.13.1, “SELECT ... INTO Statement”
</a>
.
</p>
<p>
The list of
<em class="replaceable">
<code>
select_expr
</code>
</em>
terms comprises
the select list that indicates which columns to retrieve. Terms
specify a column or expression or can use
<code class="literal">
*
</code>
-shorthand:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
A select list consisting only of a single unqualified
<code class="literal">
*
</code>
can be used as shorthand to select all
columns from all tables:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa95357462"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t1 <span class="token keyword">INNER</span> <span class="token keyword">JOIN</span> t2 <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
<code class="literal">
<em class="replaceable">
<code>
tbl_name
</code>
</em>
.*
</code>
can
be used as a qualified shorthand to select all columns from
the named table:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa48629154"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> t1<span class="token punctuation">.</span><span class="token operator">*</span><span class="token punctuation">,</span> t2<span class="token punctuation">.</span><span class="token operator">*</span> <span class="token keyword">FROM</span> t1 <span class="token keyword">INNER</span> <span class="token keyword">JOIN</span> t2 <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
If a table has invisible columns,
<code class="literal">
*
</code>
and
<code class="literal">
<em class="replaceable">
<code>
tbl_name
</code>
</em>
.*
</code>
do
not include them. To be included, invisible columns must be
referenced explicitly.
</p>
</li>
<li class="listitem">
<p>
Use of an unqualified
<code class="literal">
*
</code>
with other items in
the select list may produce a parse error. For example:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa49923706"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> id<span class="token punctuation">,</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t1</code></pre>
</div>
<p>
To avoid this problem, use a qualified
<code class="literal">
<em class="replaceable">
<code>
tbl_name
</code>
</em>
.*
</code>
reference:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa64800390"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> id<span class="token punctuation">,</span> t1<span class="token punctuation">.</span><span class="token operator">*</span> <span class="token keyword">FROM</span> t1</code></pre>
</div>
<p>
Use qualified
<code class="literal">
<em class="replaceable">
<code>
tbl_name
</code>
</em>
.*
</code>
references for each table in the select list:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa25879"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token function">AVG</span><span class="token punctuation">(</span>score<span class="token punctuation">)</span><span class="token punctuation">,</span> t1<span class="token punctuation">.</span><span class="token operator">*</span> <span class="token keyword">FROM</span> t1 <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span></code></pre>
</div>
</li>
</ul>
</div>
<p>
The following list provides additional information about other
<code class="literal">
SELECT
</code>
clauses:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="indexterm" name="idm46045180956688">
</a>
<a class="indexterm" name="idm46045180955200">
</a>
A
<em class="replaceable">
<code>
select_expr
</code>
</em>
can be given an alias
using
<code class="literal">
AS
<em class="replaceable">
<code>
alias_name
</code>
</em>
</code>
. The alias is
used as the expression's column name and can be used in
<code class="literal">
GROUP BY
</code>
,
<code class="literal">
ORDER BY
</code>
, or
<code class="literal">
HAVING
</code>
clauses. For example:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa37884424"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token function">CONCAT</span><span class="token punctuation">(</span>last_name<span class="token punctuation">,</span><span class="token string">', '</span><span class="token punctuation">,</span>first_name<span class="token punctuation">)</span> <span class="token keyword">AS</span> full_name
<span class="token keyword">FROM</span> mytable <span class="token keyword">ORDER</span> <span class="token keyword">BY</span> full_name<span class="token punctuation">;</span></code></pre>
</div>
<p>
The
<code class="literal">
AS
</code>
keyword is optional when aliasing a
<em class="replaceable">
<code>
select_expr
</code>
</em>
with an identifier. The
preceding example could have been written like this:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa9397775"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token function">CONCAT</span><span class="token punctuation">(</span>last_name<span class="token punctuation">,</span><span class="token string">', '</span><span class="token punctuation">,</span>first_name<span class="token punctuation">)</span> full_name
<span class="token keyword">FROM</span> mytable <span class="token keyword">ORDER</span> <span class="token keyword">BY</span> full_name<span class="token punctuation">;</span></code></pre>
</div>
<p>
However, because the
<code class="literal">
AS
</code>
is optional, a
subtle problem can occur if you forget the comma between two
<em class="replaceable">
<code>
select_expr
</code>
</em>
expressions: MySQL
interprets the second as an alias name. For example, in the
following statement,
<code class="literal">
columnb
</code>
is treated as
an alias name:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa28183320"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> columna columnb <span class="token keyword">FROM</span> mytable<span class="token punctuation">;</span></code></pre>
</div>
<p>
For this reason, it is good practice to be in the habit of
using
<code class="literal">
AS
</code>
explicitly when specifying column
aliases.
</p>
<p>
It is not permissible to refer to a column alias in a
<code class="literal">
WHERE
</code>
clause, because the column value
might not yet be determined when the
<code class="literal">
WHERE
</code>
clause is executed. See
<a class="xref" href="problems-with-alias.html" title="B.3.4.4 Problems with Column Aliases">
Section B.3.4.4, “Problems with Column Aliases”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a class="indexterm" name="idm46045180938496">
</a>
<a class="indexterm" name="idm46045180937424">
</a>
The
<code class="literal">
FROM
<em class="replaceable">
<code>
table_references
</code>
</em>
</code>
clause
indicates the table or tables from which to retrieve rows. If
you name more than one table, you are performing a join. For
information on join syntax, see
<a class="xref" href="join.html" title="15.2.13.2 JOIN Clause">
Section 15.2.13.2, “JOIN Clause”
</a>
. For
each table specified, you can optionally specify an alias.
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa73439598"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><em class="replaceable">tbl_name</em> <span class="token punctuation">[</span><span class="token punctuation">[</span><span class="token keyword">AS</span><span class="token punctuation">]</span> <em class="replaceable">alias</em><span class="token punctuation">]</span> <span class="token punctuation">[</span><em class="replaceable">index_hint</em><span class="token punctuation">]</span></code></pre>
</div>
<a class="indexterm" name="idm46045180932256">
</a>
<a class="indexterm" name="idm46045180931184">
</a>
<p>
The use of index hints provides the optimizer with information
about how to choose indexes during query processing. For a
description of the syntax for specifying these hints, see
<a class="xref" href="index-hints.html" title="10.9.4 Index Hints">
Section 10.9.4, “Index Hints”
</a>
.
</p>
<p>
You can use
<code class="literal">
SET
max_seeks_for_key=
<em class="replaceable">
<code>
value
</code>
</em>
</code>
as an alternative way to force MySQL to prefer key scans
instead of table scans. See
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
.
</p>
</li>
<li class="listitem">
<p>
You can refer to a table within the default database as
<em class="replaceable">
<code>
tbl_name
</code>
</em>
, or as
<em class="replaceable">
<code>
db_name
</code>
</em>
.
<em class="replaceable">
<code>
tbl_name
</code>
</em>
to specify a database explicitly. You can refer to a column as
<em class="replaceable">
<code>
col_name
</code>
</em>
,
<em class="replaceable">
<code>
tbl_name
</code>
</em>
.
<em class="replaceable">
<code>
col_name
</code>
</em>
,
or
<em class="replaceable">
<code>
db_name
</code>
</em>
.
<em class="replaceable">
<code>
tbl_name
</code>
</em>
.
<em class="replaceable">
<code>
col_name
</code>
</em>
.
You need not specify a
<em class="replaceable">
<code>
tbl_name
</code>
</em>
or
<em class="replaceable">
<code>
db_name
</code>
</em>
.
<em class="replaceable">
<code>
tbl_name
</code>
</em>
prefix for a column reference unless the reference would be
ambiguous. See
<a class="xref" href="identifier-qualifiers.html" title="11.2.2 Identifier Qualifiers">
Section 11.2.2, “Identifier Qualifiers”
</a>
, for
examples of ambiguity that require the more explicit column
reference forms.
</p>
</li>
<li class="listitem">
<p>
<a class="indexterm" name="idm46045180918496">
</a>
<a class="indexterm" name="idm46045180917040">
</a>
A table reference can be aliased using
<code class="literal">
<em class="replaceable">
<code>
tbl_name
</code>
</em>
AS
<em class="replaceable">
<code>
alias_name
</code>
</em>
</code>
or
<em class="replaceable">
<code>
tbl_name alias_name
</code>
</em>
. These
statements are equivalent:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa43824691"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> t1<span class="token punctuation">.</span><span class="token keyword">name</span><span class="token punctuation">,</span> t2<span class="token punctuation">.</span>salary <span class="token keyword">FROM</span> employee <span class="token keyword">AS</span> t1<span class="token punctuation">,</span> info <span class="token keyword">AS</span> t2
<span class="token keyword">WHERE</span> t1<span class="token punctuation">.</span><span class="token keyword">name</span> <span class="token operator">=</span> t2<span class="token punctuation">.</span><span class="token keyword">name</span><span class="token punctuation">;</span>
<span class="token keyword">SELECT</span> t1<span class="token punctuation">.</span><span class="token keyword">name</span><span class="token punctuation">,</span> t2<span class="token punctuation">.</span>salary <span class="token keyword">FROM</span> employee t1<span class="token punctuation">,</span> info t2
<span class="token keyword">WHERE</span> t1<span class="token punctuation">.</span><span class="token keyword">name</span> <span class="token operator">=</span> t2<span class="token punctuation">.</span><span class="token keyword">name</span><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
<a class="indexterm" name="idm46045180912272">
</a>
Columns selected for output can be referred to in
<code class="literal">
ORDER BY
</code>
and
<code class="literal">
GROUP BY
</code>
clauses using column names, column aliases, or column
positions. Column positions are integers and begin with 1:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa89768865"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> college<span class="token punctuation">,</span> region<span class="token punctuation">,</span> seed <span class="token keyword">FROM</span> tournament
<span class="token keyword">ORDER</span> <span class="token keyword">BY</span> region<span class="token punctuation">,</span> seed<span class="token punctuation">;</span>
<span class="token keyword">SELECT</span> college<span class="token punctuation">,</span> region <span class="token keyword">AS</span> r<span class="token punctuation">,</span> seed <span class="token keyword">AS</span> s <span class="token keyword">FROM</span> tournament
<span class="token keyword">ORDER</span> <span class="token keyword">BY</span> r<span class="token punctuation">,</span> s<span class="token punctuation">;</span>
<span class="token keyword">SELECT</span> college<span class="token punctuation">,</span> region<span class="token punctuation">,</span> seed <span class="token keyword">FROM</span> tournament
<span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
To sort in reverse order, add the
<code class="literal">
DESC
</code>
(descending) keyword to the name of the column in the
<code class="literal">
ORDER BY
</code>
clause that you are sorting by.
The default is ascending order; this can be specified
explicitly using the
<code class="literal">
ASC
</code>
keyword.
</p>
<p>
If
<code class="literal">
ORDER BY
</code>
occurs within a parenthesized
query expression and also is applied in the outer query, the
results are undefined and may change in a future version of
MySQL.
</p>
<p>
Use of column positions is deprecated because the syntax has
been removed from the SQL standard.
</p>
</li>
<li class="listitem">
<p>
<a class="indexterm" name="idm46045180903056">
</a>
<a class="indexterm" name="idm46045180901568">
</a>
When you use
<code class="literal">
ORDER BY
</code>
or
<code class="literal">
GROUP
BY
</code>
to sort a column in a
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
, the server sorts values
using only the initial number of bytes indicated by the
<a class="link" href="server-system-variables.html#sysvar_max_sort_length">
<code class="literal">
max_sort_length
</code>
</a>
system
variable.
</p>
</li>
<li class="listitem">
<p>
MySQL extends the use of
<code class="literal">
GROUP BY
</code>
to permit
selecting fields that are not mentioned in the
<code class="literal">
GROUP
BY
</code>
clause. If you are not getting the results that
you expect from your query, please read the description of
<code class="literal">
GROUP BY
</code>
found in
<a class="xref" href="aggregate-functions-and-modifiers.html" title="14.19 Aggregate Functions">
Section 14.19, “Aggregate Functions”
</a>
.
</p>
</li>
<li class="listitem">
<p>
The
<code class="literal">
HAVING
</code>
clause, like the
<code class="literal">
WHERE
</code>
clause, specifies selection
conditions. The
<code class="literal">
WHERE
</code>
clause specifies
conditions on columns in the select list, but cannot refer to
aggregate functions. The
<code class="literal">
HAVING
</code>
clause
specifies conditions on groups, typically formed by the
<code class="literal">
GROUP BY
</code>
clause. The query result includes
only groups satisfying the
<code class="literal">
HAVING
</code>
conditions. (If no
<code class="literal">
GROUP BY
</code>
is present, all
rows implicitly form a single aggregate group.)
</p>
<p>
The
<code class="literal">
HAVING
</code>
clause is applied nearly last,
just before items are sent to the client, with no
optimization. (
<code class="literal">
LIMIT
</code>
is applied after
<code class="literal">
HAVING
</code>
.)
</p>
<a class="indexterm" name="idm46045180883152">
</a>
<p>
The SQL standard requires that
<code class="literal">
HAVING
</code>
must
reference only columns in the
<code class="literal">
GROUP BY
</code>
clause or columns used in aggregate functions. However, MySQL
supports an extension to this behavior, and permits
<code class="literal">
HAVING
</code>
to refer to columns in the
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
list and columns in
outer subqueries as well.
</p>
<p>
If the
<code class="literal">
HAVING
</code>
clause refers to a column
that is ambiguous, a warning occurs. In the following
statement,
<code class="literal">
col2
</code>
is ambiguous because it is
used as both an alias and a column name:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa16416404"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token function">COUNT</span><span class="token punctuation">(</span>col1<span class="token punctuation">)</span> <span class="token keyword">AS</span> col2 <span class="token keyword">FROM</span> t <span class="token keyword">GROUP</span> <span class="token keyword">BY</span> col2 <span class="token keyword">HAVING</span> col2 <span class="token operator">=</span> <span class="token number">2</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
Preference is given to standard SQL behavior, so if a
<code class="literal">
HAVING
</code>
column name is used both in
<code class="literal">
GROUP BY
</code>
and as an aliased column in the
select column list, preference is given to the column in the
<code class="literal">
GROUP BY
</code>
column.
</p>
</li>
<li class="listitem">
<p>
Do not use
<code class="literal">
HAVING
</code>
for items that should be
in the
<code class="literal">
WHERE
</code>
clause. For example, do not
write the following:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa72263128"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <em class="replaceable">col_name</em> <span class="token keyword">FROM</span> <em class="replaceable">tbl_name</em> <span class="token keyword">HAVING</span> <em class="replaceable">col_name</em> <span class="token operator">></span> <span class="token number">0</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
Write this instead:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa14787361"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <em class="replaceable">col_name</em> <span class="token keyword">FROM</span> <em class="replaceable">tbl_name</em> <span class="token keyword">WHERE</span> <em class="replaceable">col_name</em> <span class="token operator">></span> <span class="token number">0</span><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
The
<code class="literal">
HAVING
</code>
clause can refer to aggregate
functions, which the
<code class="literal">
WHERE
</code>
clause cannot:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa11215538"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token keyword">user</span><span class="token punctuation">,</span> <span class="token function">MAX</span><span class="token punctuation">(</span>salary<span class="token punctuation">)</span> <span class="token keyword">FROM</span> users
<span class="token keyword">GROUP</span> <span class="token keyword">BY</span> <span class="token keyword">user</span> <span class="token keyword">HAVING</span> <span class="token function">MAX</span><span class="token punctuation">(</span>salary<span class="token punctuation">)</span> <span class="token operator">></span> <span class="token number">10</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
(This did not work in some older versions of MySQL.)
</p>
</li>
<li class="listitem">
<p>
MySQL permits duplicate column names. That is, there can be
more than one
<em class="replaceable">
<code>
select_expr
</code>
</em>
with the
same name. This is an extension to standard SQL. Because MySQL
also permits
<code class="literal">
GROUP BY
</code>
and
<code class="literal">
HAVING
</code>
to refer to
<em class="replaceable">
<code>
select_expr
</code>
</em>
values, this can result
in an ambiguity:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa39863627"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token number">12</span> <span class="token keyword">AS</span> a<span class="token punctuation">,</span> a <span class="token keyword">FROM</span> t <span class="token keyword">GROUP</span> <span class="token keyword">BY</span> a<span class="token punctuation">;</span></code></pre>
</div>
<p>
In that statement, both columns have the name
<code class="literal">
a
</code>
. To ensure that the correct column is
used for grouping, use different names for each
<em class="replaceable">
<code>
select_expr
</code>
</em>
.
</p>
</li>
<li class="listitem">
<p>
The
<code class="literal">
WINDOW
</code>
clause, if present, defines
named windows that can be referred to by window functions. For
details, see
<a class="xref" href="window-functions-named-windows.html" title="14.20.4 Named Windows">
Section 14.20.4, “Named Windows”
</a>
.
</p>
</li>
<li class="listitem">
<p>
MySQL resolves unqualified column or alias references in
<code class="literal">
ORDER BY
</code>
clauses by searching in the
<em class="replaceable">
<code>
select_expr
</code>
</em>
values, then in the
columns of the tables in the
<code class="literal">
FROM
</code>
clause.
For
<code class="literal">
GROUP BY
</code>
or
<code class="literal">
HAVING
</code>
clauses, it searches the
<code class="literal">
FROM
</code>
clause before
searching in the
<em class="replaceable">
<code>
select_expr
</code>
</em>
values. (For
<code class="literal">
GROUP BY
</code>
and
<code class="literal">
HAVING
</code>
, this differs from the pre-MySQL 5.0
behavior that used the same rules as for
<code class="literal">
ORDER
BY
</code>
.)
</p>
</li>
<li class="listitem">
<p>
<a class="indexterm" name="idm46045180844432">
</a>
The
<code class="literal">
LIMIT
</code>
clause can be used to constrain
the number of rows returned by the
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
statement.
<code class="literal">
LIMIT
</code>
takes one or two numeric arguments,
which must both be nonnegative integer constants, with these
exceptions:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
Within prepared statements,
<code class="literal">
LIMIT
</code>
parameters can be specified using
<code class="literal">
?
</code>
placeholder markers.
</p>
</li>
<li class="listitem">
<p>
Within stored programs,
<code class="literal">
LIMIT
</code>
parameters can be specified using integer-valued routine
parameters or local variables.
</p>
</li>
</ul>
</div>
<p>
With two arguments, the first argument specifies the offset of
the first row to return, and the second specifies the maximum
number of rows to return. The offset of the initial row is 0
(not 1):
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa42466129"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> tbl <span class="token keyword">LIMIT</span> <span class="token number">5</span><span class="token punctuation">,</span><span class="token number">10</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true"># Retrieve rows 6-15</span></code></pre>
</div>
<p>
To retrieve all rows from a certain offset up to the end of
the result set, you can use some large number for the second
parameter. This statement retrieves all rows from the 96th row
to the last:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa62037368"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> tbl <span class="token keyword">LIMIT</span> <span class="token number">95</span><span class="token punctuation">,</span><span class="token number">18446744073709551615</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
With one argument, the value specifies the number of rows to
return from the beginning of the result set:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa11504561"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> tbl <span class="token keyword">LIMIT</span> <span class="token number">5</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true"># Retrieve first 5 rows</span></code></pre>
</div>
<p>
In other words,
<code class="literal">
LIMIT
<em class="replaceable">
<code>
row_count
</code>
</em>
</code>
is equivalent
to
<code class="literal">
LIMIT 0,
<em class="replaceable">
<code>
row_count
</code>
</em>
</code>
.
</p>
<p>
For prepared statements, you can use placeholders. The
following statements return one row from the
<code class="literal">
tbl
</code>
table:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa76029112"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SET</span> <span class="token variable">@a</span><span class="token operator">=</span><span class="token number">1</span><span class="token punctuation">;</span>
<span class="token keyword">PREPARE</span> STMT <span class="token keyword">FROM</span> <span class="token string">'SELECT * FROM tbl LIMIT ?'</span><span class="token punctuation">;</span>
<span class="token keyword">EXECUTE</span> STMT <span class="token keyword">USING</span> <span class="token variable">@a</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
The following statements return the second to sixth rows from
the
<code class="literal">
tbl
</code>
table:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa90654793"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SET</span> <span class="token variable">@skip</span><span class="token operator">=</span><span class="token number">1</span><span class="token punctuation">;</span> <span class="token keyword">SET</span> <span class="token variable">@numrows</span><span class="token operator">=</span><span class="token number">5</span><span class="token punctuation">;</span>
<span class="token keyword">PREPARE</span> STMT <span class="token keyword">FROM</span> <span class="token string">'SELECT * FROM tbl LIMIT ?, ?'</span><span class="token punctuation">;</span>
<span class="token keyword">EXECUTE</span> STMT <span class="token keyword">USING</span> <span class="token variable">@skip</span><span class="token punctuation">,</span> <span class="token variable">@numrows</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
For compatibility with PostgreSQL, MySQL also supports the
<code class="literal">
LIMIT
<em class="replaceable">
<code>
row_count
</code>
</em>
OFFSET
<em class="replaceable">
<code>
offset
</code>
</em>
</code>
syntax.
</p>
<p>
If
<code class="literal">
LIMIT
</code>
occurs within a parenthesized
query expression and also is applied in the outer query, the
results are undefined and may change in a future version of
MySQL.
</p>
</li>
<li class="listitem">
<p>
The
<a class="link" href="select-into.html" title="15.2.13.1 SELECT ... INTO Statement">
<code class="literal">
SELECT ...
INTO
</code>
</a>
form of
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
enables the query result to be written to a file or stored in
variables. For more information, see
<a class="xref" href="select-into.html" title="15.2.13.1 SELECT ... INTO Statement">
Section 15.2.13.1, “SELECT ... INTO Statement”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a class="indexterm" name="idm46045180816432">
</a>
<a class="indexterm" name="idm46045180815360">
</a>
<a class="indexterm" name="idm46045180814288">
</a>
<a class="indexterm" name="idm46045180813216">
</a>
<a class="indexterm" name="idm46045180812144">
</a>
If you use
<code class="literal">
FOR UPDATE
</code>
with a storage engine
that uses page or row locks, rows examined by the query are
write-locked until the end of the current transaction.
</p>
<p>
You cannot use
<code class="literal">
FOR UPDATE
</code>
as part of the
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
in a statement such as
<a class="link" href="create-table-select.html" title="15.1.20.4 CREATE TABLE ... SELECT Statement">
<code class="literal">
CREATE
TABLE
<em class="replaceable">
<code>
new_table
</code>
</em>
SELECT ... FROM
<em class="replaceable">
<code>
old_table
</code>
</em>
...
</code>
</a>
. (If you
attempt to do so, the statement is rejected with the error
<span class="errortext">
Can't update table
'
<em class="replaceable">
<code>
old_table
</code>
</em>
' while
'
<em class="replaceable">
<code>
new_table
</code>
</em>
' is being
created
</span>
.)
</p>
<p>
<code class="literal">
FOR SHARE
</code>
and
<code class="literal">
LOCK IN SHARE
MODE
</code>
set shared locks that permit other transactions
to read the examined rows but not to update or delete them.
<code class="literal">
FOR SHARE
</code>
and
<code class="literal">
LOCK IN SHARE
MODE
</code>
are equivalent. However,
<code class="literal">
FOR
SHARE
</code>
, like
<code class="literal">
FOR UPDATE
</code>
, supports
<code class="literal">
NOWAIT
</code>
,
<code class="literal">
SKIP LOCKED
</code>
, and
<code class="literal">
OF
<em class="replaceable">
<code>
tbl_name
</code>
</em>
</code>
options.
<code class="literal">
FOR SHARE
</code>
is a replacement for
<code class="literal">
LOCK IN SHARE MODE
</code>
, but
<code class="literal">
LOCK IN
SHARE MODE
</code>
remains available for backward
compatibility.
</p>
<p>
<code class="literal">
NOWAIT
</code>
causes a
<code class="literal">
FOR
UPDATE
</code>
or
<code class="literal">
FOR SHARE
</code>
query to
execute immediately, returning an error if a row lock cannot
be obtained due to a lock held by another transaction.
</p>
<p>
<code class="literal">
SKIP LOCKED
</code>
causes a
<code class="literal">
FOR
UPDATE
</code>
or
<code class="literal">
FOR SHARE
</code>
query to
execute immediately, excluding rows from the result set that
are locked by another transaction.
</p>
<p>
<code class="literal">
NOWAIT
</code>
and
<code class="literal">
SKIP LOCKED
</code>
options are unsafe for statement-based replication.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
Queries that skip locked rows return an inconsistent view of
the data.
<code class="literal">
SKIP LOCKED
</code>
is therefore not
suitable for general transactional work. However, it may be
used to avoid lock contention when multiple sessions access
the same queue-like table.
</p>
</div>
<p>
<code class="literal">
OF
<em class="replaceable">
<code>
tbl_name
</code>
</em>
</code>
applies
<code class="literal">
FOR UPDATE
</code>
and
<code class="literal">
FOR
SHARE
</code>
queries to named tables. For example:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa86661077"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t1<span class="token punctuation">,</span> t2 <span class="token keyword">FOR</span> <span class="token keyword">SHARE</span> <span class="token keyword">OF</span> t1 <span class="token keyword">FOR</span> <span class="token keyword">UPDATE</span> <span class="token keyword">OF</span> t2<span class="token punctuation">;</span></code></pre>
</div>
<p>
All tables referenced by the query block are locked when
<code class="literal">
OF
<em class="replaceable">
<code>
tbl_name
</code>
</em>
</code>
is
omitted. Consequently, using a locking clause without
<code class="literal">
OF
<em class="replaceable">
<code>
tbl_name
</code>
</em>
</code>
in
combination with another locking clause returns an error.
Specifying the same table in multiple locking clauses returns
an error. If an alias is specified as the table name in the
<code class="literal">
SELECT
</code>
statement, a locking clause may only
use the alias. If the
<code class="literal">
SELECT
</code>
statement does
not specify an alias explicitly, the locking clause may only
specify the actual table name.
</p>
<p>
For more information about
<code class="literal">
FOR UPDATE
</code>
and
<code class="literal">
FOR SHARE
</code>
, see
<a class="xref" href="innodb-locking-reads.html" title="17.7.2.4 Locking Reads">
Section 17.7.2.4, “Locking Reads”
</a>
. For additional
information about
<code class="literal">
NOWAIT
</code>
and
<code class="literal">
SKIP
LOCKED
</code>
options, see
<a class="xref" href="innodb-locking-reads.html#innodb-locking-reads-nowait-skip-locked" title="Locking Read Concurrency with NOWAIT and SKIP LOCKED">
Locking Read Concurrency with NOWAIT and SKIP LOCKED
</a>
.
</p>
</li>
</ul>
</div>
<p>
Following the
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
keyword, you
can use a number of modifiers that affect the operation of the
statement.
<code class="literal">
HIGH_PRIORITY
</code>
,
<code class="literal">
STRAIGHT_JOIN
</code>
, and modifiers beginning with
<code class="literal">
SQL_
</code>
are MySQL extensions to standard SQL.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
The
<code class="literal">
ALL
</code>
and
<code class="literal">
DISTINCT
</code>
modifiers specify whether duplicate rows should be returned.
<code class="literal">
ALL
</code>
(the default) specifies that all
matching rows should be returned, including duplicates.
<code class="literal">
DISTINCT
</code>
specifies removal of duplicate
rows from the result set. It is an error to specify both
modifiers.
<code class="literal">
DISTINCTROW
</code>
is a synonym for
<code class="literal">
DISTINCT
</code>
.
</p>
<p>
<code class="literal">
DISTINCT
</code>
can be used with a query that also
uses
<code class="literal">
WITH ROLLUP
</code>
.
</p>
<a class="indexterm" name="idm46045180760944">
</a>
<a class="indexterm" name="idm46045180759488">
</a>
<a class="indexterm" name="idm46045180758000">
</a>
</li>
<li class="listitem">
<p>
<code class="literal">
HIGH_PRIORITY
</code>
gives the
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
higher priority than a
statement that updates a table. You should use this only for
queries that are very fast and must be done at once. A
<code class="literal">
SELECT HIGH_PRIORITY
</code>
query that is issued
while the table is locked for reading runs even if there is an
update statement waiting for the table to be free. This
affects only storage engines that use only table-level locking
(such as
<code class="literal">
MyISAM
</code>
,
<code class="literal">
MEMORY
</code>
,
and
<code class="literal">
MERGE
</code>
).
</p>
<a class="indexterm" name="idm46045180750544">
</a>
<p>
<code class="literal">
HIGH_PRIORITY
</code>
cannot be used with
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
statements that are part
of a
<a class="link" href="union.html" title="15.2.18 UNION Clause">
<code class="literal">
UNION
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
STRAIGHT_JOIN
</code>
forces the optimizer to join
the tables in the order in which they are listed in the
<code class="literal">
FROM
</code>
clause. You can use this to speed up a
query if the optimizer joins the tables in nonoptimal order.
<code class="literal">
STRAIGHT_JOIN
</code>
also can be used in the
<em class="replaceable">
<code>
table_references
</code>
</em>
list. See
<a class="xref" href="join.html" title="15.2.13.2 JOIN Clause">
Section 15.2.13.2, “JOIN Clause”
</a>
.
</p>
<a class="indexterm" name="idm46045180741168">
</a>
<a class="indexterm" name="idm46045180739680">
</a>
<a class="indexterm" name="idm46045180738192">
</a>
<p>
<code class="literal">
STRAIGHT_JOIN
</code>
does not apply to any table
that the optimizer treats as a
<a class="link" href="explain-output.html#jointype_const">
<code class="literal">
const
</code>
</a>
or
<a class="link" href="explain-output.html#jointype_system">
<code class="literal">
system
</code>
</a>
table. Such a table
produces a single row, is read during the optimization phase
of query execution, and references to its columns are replaced
with the appropriate column values before query execution
proceeds. These tables appear first in the query plan
displayed by
<a class="link" href="explain.html" title="15.8.2 EXPLAIN Statement">
<code class="literal">
EXPLAIN
</code>
</a>
. See
<a class="xref" href="using-explain.html" title="10.8.1 Optimizing Queries with EXPLAIN">
Section 10.8.1, “Optimizing Queries with EXPLAIN”
</a>
. This exception may not apply
to
<a class="link" href="explain-output.html#jointype_const">
<code class="literal">
const
</code>
</a>
or
<a class="link" href="explain-output.html#jointype_system">
<code class="literal">
system
</code>
</a>
tables that are used
on the
<code class="literal">
NULL
</code>
-complemented side of an outer
join (that is, the right-side table of a
<code class="literal">
LEFT
JOIN
</code>
or the left-side table of a
<code class="literal">
RIGHT
JOIN
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SQL_BIG_RESULT
</code>
or
<code class="literal">
SQL_SMALL_RESULT
</code>
can be used with
<code class="literal">
GROUP BY
</code>
or
<code class="literal">
DISTINCT
</code>
to
tell the optimizer that the result set has many rows or is
small, respectively. For
<code class="literal">
SQL_BIG_RESULT
</code>
,
MySQL directly uses disk-based temporary tables if they are
created, and prefers sorting to using a temporary table with a
key on the
<code class="literal">
GROUP BY
</code>
elements. For
<code class="literal">
SQL_SMALL_RESULT
</code>
, MySQL uses in-memory
temporary tables to store the resulting table instead of using
sorting. This should not normally be needed.
</p>
<a class="indexterm" name="idm46045180719888">
</a>
<a class="indexterm" name="idm46045180718400">
</a>
</li>
<li class="listitem">
<p>
<code class="literal">
SQL_BUFFER_RESULT
</code>
forces the result to be
put into a temporary table. This helps MySQL free the table
locks early and helps in cases where it takes a long time to
send the result set to the client. This modifier can be used
only for top-level
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
statements, not for subqueries or following
<a class="link" href="union.html" title="15.2.18 UNION Clause">
<code class="literal">
UNION
</code>
</a>
.
</p>
<a class="indexterm" name="idm46045180712656">
</a>
</li>
<li class="listitem">
<p>
<code class="literal">
SQL_CALC_FOUND_ROWS
</code>
tells MySQL to
calculate how many rows there would be in the result set,
disregarding any
<code class="literal">
LIMIT
</code>
clause. The number
of rows can then be retrieved with
<code class="literal">
SELECT
FOUND_ROWS()
</code>
. See
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
The
<code class="literal">
SQL_CALC_FOUND_ROWS
</code>
query modifier
and accompanying
<a class="link" href="information-functions.html#function_found-rows">
<code class="literal">
FOUND_ROWS()
</code>
</a>
function are deprecated; expect them to be removed in a
future version of MySQL. See the description of
<a class="link" href="information-functions.html#function_found-rows">
<code class="literal">
FOUND_ROWS()
</code>
</a>
for information
about an alternative strategy.
</p>
</div>
<a class="indexterm" name="idm46045180703216">
</a>
</li>
<li class="listitem">
<p>
The
<code class="literal">
SQL_CACHE
</code>
and
<code class="literal">
SQL_NO_CACHE
</code>
modifiers were used with the
query cache prior to MySQL 8.4. The query cache
was removed in MySQL 8.4. The
<code class="literal">
SQL_CACHE
</code>
modifier was removed as well.
<code class="literal">
SQL_NO_CACHE
</code>
is deprecated, and has no
effect; expect it to be removed in a future MySQL release.
</p>
<a class="indexterm" name="idm46045180697792">
</a>
<a class="indexterm" name="idm46045180696304">
</a>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/index-btree-hash.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="index-btree-hash">
</a>
10.3.9 Comparison of B-Tree and Hash Indexes
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045227233648">
</a>
<a class="indexterm" name="idm46045227232608">
</a>
<p>
Understanding the B-tree and hash data structures can help
predict how different queries perform on different storage
engines that use these data structures in their indexes,
particularly for the
<code class="literal">
MEMORY
</code>
storage engine
that lets you choose B-tree or hash indexes.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="xref" href="index-btree-hash.html#btree-index-characteristics" title="B-Tree Index Characteristics">
B-Tree Index Characteristics
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="index-btree-hash.html#hash-index-characteristics" title="Hash Index Characteristics">
Hash Index Characteristics
</a>
</p>
</li>
</ul>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="btree-index-characteristics">
</a>
B-Tree Index Characteristics
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045227226576">
</a>
<a class="indexterm" name="idm46045227225088">
</a>
<a class="indexterm" name="idm46045227223600">
</a>
<a class="indexterm" name="idm46045227222112">
</a>
<p>
A B-tree index can be used for column comparisons in
expressions that use the
<a class="link" href="comparison-operators.html#operator_equal">
<code class="literal">
=
</code>
</a>
,
<a class="link" href="comparison-operators.html#operator_greater-than">
<code class="literal">
>
</code>
</a>
,
<a class="link" href="comparison-operators.html#operator_greater-than-or-equal">
<code class="literal">
>=
</code>
</a>
,
<a class="link" href="comparison-operators.html#operator_less-than">
<code class="literal">
<
</code>
</a>
,
<a class="link" href="comparison-operators.html#operator_less-than-or-equal">
<code class="literal">
<=
</code>
</a>
,
or
<a class="link" href="comparison-operators.html#operator_between">
<code class="literal">
BETWEEN
</code>
</a>
operators. The index
also can be used for
<a class="link" href="string-comparison-functions.html#operator_like">
<code class="literal">
LIKE
</code>
</a>
comparisons if the argument to
<a class="link" href="string-comparison-functions.html#operator_like">
<code class="literal">
LIKE
</code>
</a>
is a constant string that
does not start with a wildcard character. For example, the
following
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
statements use
indexes:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa19789403"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> <em class="replaceable">tbl_name</em> <span class="token keyword">WHERE</span> <em class="replaceable">key_col</em> <span class="token operator">LIKE</span> <span class="token string">'Patrick%'</span><span class="token punctuation">;</span>
<span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> <em class="replaceable">tbl_name</em> <span class="token keyword">WHERE</span> <em class="replaceable">key_col</em> <span class="token operator">LIKE</span> <span class="token string">'Pat%_ck%'</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
In the first statement, only rows with
<code class="literal">
'Patrick'
<=
<em class="replaceable">
<code>
key_col
</code>
</em>
<
'Patricl'
</code>
are considered. In the second statement,
only rows with
<code class="literal">
'Pat' <=
<em class="replaceable">
<code>
key_col
</code>
</em>
< 'Pau'
</code>
are
considered.
</p>
<p>
The following
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
statements
do not use indexes:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa31302888"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> <em class="replaceable">tbl_name</em> <span class="token keyword">WHERE</span> <em class="replaceable">key_col</em> <span class="token operator">LIKE</span> <span class="token string">'%Patrick%'</span><span class="token punctuation">;</span>
<span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> <em class="replaceable">tbl_name</em> <span class="token keyword">WHERE</span> <em class="replaceable">key_col</em> <span class="token operator">LIKE</span> <em class="replaceable">other_col</em><span class="token punctuation">;</span></code></pre>
</div>
<p>
In the first statement, the
<a class="link" href="string-comparison-functions.html#operator_like">
<code class="literal">
LIKE
</code>
</a>
value begins with a wildcard character. In the second
statement, the
<a class="link" href="string-comparison-functions.html#operator_like">
<code class="literal">
LIKE
</code>
</a>
value is not
a constant.
</p>
<p>
If you use
<code class="literal">
... LIKE
'%
<em class="replaceable">
<code>
string
</code>
</em>
%'
</code>
and
<em class="replaceable">
<code>
string
</code>
</em>
is longer than three
characters, MySQL uses the
<span class="firstterm">
Turbo
Boyer-Moore algorithm
</span>
to initialize the pattern for
the string and then uses this pattern to perform the search
more quickly.
</p>
<a class="indexterm" name="idm46045227192320">
</a>
<a class="indexterm" name="idm46045227190832">
</a>
<p>
A search using
<code class="literal">
<em class="replaceable">
<code>
col_name
</code>
</em>
IS
NULL
</code>
employs indexes if
<em class="replaceable">
<code>
col_name
</code>
</em>
is indexed.
</p>
<p>
Any index that does not span all
<a class="link" href="logical-operators.html#operator_and">
<code class="literal">
AND
</code>
</a>
levels in the
<code class="literal">
WHERE
</code>
clause is not used to optimize the
query. In other words, to be able to use an index, a prefix of
the index must be used in every
<a class="link" href="logical-operators.html#operator_and">
<code class="literal">
AND
</code>
</a>
group.
</p>
<p>
The following
<code class="literal">
WHERE
</code>
clauses use indexes:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa61121285"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token keyword">WHERE</span> <em class="replaceable">index_part1</em><span class="token operator">=</span><span class="token number">1</span> <span class="token operator">AND</span> <em class="replaceable">index_part2</em><span class="token operator">=</span><span class="token number">2</span> <span class="token operator">AND</span> <em class="replaceable">other_column</em><span class="token operator">=</span><span class="token number">3</span>
<span class="token comment" spellcheck="true">/* <em class="replaceable">index</em> = 1 OR <em class="replaceable">index</em> = 2 */</span>
<span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token keyword">WHERE</span> <span class="token keyword"><em class="replaceable">index</em></span><span class="token operator">=</span><span class="token number">1</span> <span class="token operator">OR</span> A<span class="token operator">=</span><span class="token number">10</span> <span class="token operator">AND</span> <span class="token keyword"><em class="replaceable">index</em></span><span class="token operator">=</span><span class="token number">2</span>
<span class="token comment" spellcheck="true">/* optimized like "<em class="replaceable">index_part1</em>='hello'" */</span>
<span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token keyword">WHERE</span> <em class="replaceable">index_part1</em><span class="token operator">=</span><span class="token string">'hello'</span> <span class="token operator">AND</span> <em class="replaceable">index_part3</em><span class="token operator">=</span><span class="token number">5</span>
<span class="token comment" spellcheck="true">/* Can use index on <em class="replaceable">index1</em> but not on <em class="replaceable">index2</em> or <em class="replaceable">index3</em> */</span>
<span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token keyword">WHERE</span> <em class="replaceable">index1</em><span class="token operator">=</span><span class="token number">1</span> <span class="token operator">AND</span> <em class="replaceable">index2</em><span class="token operator">=</span><span class="token number">2</span> <span class="token operator">OR</span> <em class="replaceable">index1</em><span class="token operator">=</span><span class="token number">3</span> <span class="token operator">AND</span> <em class="replaceable">index3</em><span class="token operator">=</span><span class="token number">3</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
These
<code class="literal">
WHERE
</code>
clauses do
<span class="emphasis">
<em>
not
</em>
</span>
use indexes:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa53019683"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"> <span class="token comment" spellcheck="true">/* <em class="replaceable">index_part1</em> is not used */</span>
<span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token keyword">WHERE</span> <em class="replaceable">index_part2</em><span class="token operator">=</span><span class="token number">1</span> <span class="token operator">AND</span> <em class="replaceable">index_part3</em><span class="token operator">=</span><span class="token number">2</span>
<span class="token comment" spellcheck="true">/* Index is not used in both parts of the WHERE clause */</span>
<span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token keyword">WHERE</span> <span class="token keyword"><em class="replaceable">index</em></span><span class="token operator">=</span><span class="token number">1</span> <span class="token operator">OR</span> A<span class="token operator">=</span><span class="token number">10</span>
<span class="token comment" spellcheck="true">/* No index spans all rows */</span>
<span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token keyword">WHERE</span> <em class="replaceable">index_part1</em><span class="token operator">=</span><span class="token number">1</span> <span class="token operator">OR</span> <em class="replaceable">index_part2</em><span class="token operator">=</span><span class="token number">10</span></code></pre>
</div>
<p>
Sometimes MySQL does not use an index, even if one is
available. One circumstance under which this occurs is when
the optimizer estimates that using the index would require
MySQL to access a very large percentage of the rows in the
table. (In this case, a table scan is likely to be much faster
because it requires fewer seeks.) However, if such a query
uses
<code class="literal">
LIMIT
</code>
to retrieve only some of the
rows, MySQL uses an index anyway, because it can much more
quickly find the few rows to return in the result.
</p>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="hash-index-characteristics">
</a>
Hash Index Characteristics
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045227165680">
</a>
<p>
Hash indexes have somewhat different characteristics from
those just discussed:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
They are used only for equality comparisons that use the
<code class="literal">
=
</code>
or
<code class="literal">
<=>
</code>
operators (but are
<span class="emphasis">
<em>
very
</em>
</span>
fast). They
are not used for comparison operators such as
<code class="literal">
<
</code>
that find a range of values.
Systems that rely on this type of single-value lookup are
known as
<span class="quote">
“
<span class="quote">
key-value stores
</span>
”
</span>
; to use MySQL for
such applications, use hash indexes wherever possible.
</p>
</li>
<li class="listitem">
<p>
The optimizer cannot use a hash index to speed up
<code class="literal">
ORDER BY
</code>
operations. (This type of
index cannot be used to search for the next entry in
order.)
</p>
</li>
<li class="listitem">
<p>
MySQL cannot determine approximately how many rows there
are between two values (this is used by the range
optimizer to decide which index to use). This may affect
some queries if you change a
<code class="literal">
MyISAM
</code>
or
<code class="literal">
InnoDB
</code>
table to a hash-indexed
<code class="literal">
MEMORY
</code>
table.
</p>
</li>
<li class="listitem">
<p>
Only whole keys can be used to search for a row. (With a
B-tree index, any leftmost prefix of the key can be used
to find rows.)
</p>
</li>
</ul>
</div>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/create-temporary-table.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="create-temporary-table">
</a>
15.1.20.2 CREATE TEMPORARY TABLE Statement
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045185392176">
</a>
<a class="indexterm" name="idm46045185391136">
</a>
<p>
You can use the
<code class="literal">
TEMPORARY
</code>
keyword when
creating a table. A
<code class="literal">
TEMPORARY
</code>
table is
visible only within the current session, and is dropped
automatically when the session is closed. This means that two
different sessions can use the same temporary table name without
conflicting with each other or with an existing
non-
<code class="literal">
TEMPORARY
</code>
table of the same name. (The
existing table is hidden until the temporary table is dropped.)
</p>
<p>
<code class="literal">
InnoDB
</code>
does not support compressed temporary
tables. When
<a class="link" href="innodb-parameters.html#sysvar_innodb_strict_mode">
<code class="literal">
innodb_strict_mode
</code>
</a>
is enabled (the default),
<a class="link" href="create-table.html" title="15.1.20 CREATE TABLE Statement">
<code class="literal">
CREATE TEMPORARY
TABLE
</code>
</a>
returns an error if
<code class="literal">
ROW_FORMAT=COMPRESSED
</code>
or
<code class="literal">
KEY_BLOCK_SIZE
</code>
is specified. If
<a class="link" href="innodb-parameters.html#sysvar_innodb_strict_mode">
<code class="literal">
innodb_strict_mode
</code>
</a>
is disabled,
warnings are issued and the temporary table is created using a
non-compressed row format. The
<a class="link" href="innodb-parameters.html#sysvar_innodb_file_per_table">
<code class="literal">
innodb_file_per-table
</code>
</a>
option
does not affect the creation of
<code class="literal">
InnoDB
</code>
temporary tables.
</p>
<p>
<a class="link" href="create-table.html" title="15.1.20 CREATE TABLE Statement">
<code class="literal">
CREATE TABLE
</code>
</a>
causes an implicit
commit, except when used with the
<code class="literal">
TEMPORARY
</code>
keyword. See
<a class="xref" href="implicit-commit.html" title="15.3.3 Statements That Cause an Implicit Commit">
Section 15.3.3, “Statements That Cause an Implicit Commit”
</a>
.
</p>
<p>
<code class="literal">
TEMPORARY
</code>
tables have a very loose
relationship with databases (schemas). Dropping a database does
not automatically drop any
<code class="literal">
TEMPORARY
</code>
tables
created within that database.
</p>
<a class="indexterm" name="idm46045185373056">
</a>
<a class="indexterm" name="idm46045185371568">
</a>
<p>
To create a temporary table, you must have the
<a class="link" href="privileges-provided.html#priv_create-temporary-tables">
<code class="literal">
CREATE TEMPORARY TABLES
</code>
</a>
privilege. After a session has created a temporary table, the
server performs no further privilege checks on the table. The
creating session can perform any operation on the table, such as
<a class="link" href="drop-table.html" title="15.1.32 DROP TABLE Statement">
<code class="literal">
DROP TABLE
</code>
</a>
,
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
,
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
, or
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
.
</p>
<p>
One implication of this behavior is that a session can
manipulate its temporary tables even if the current user has no
privilege to create them. Suppose that the current user does not
have the
<a class="link" href="privileges-provided.html#priv_create-temporary-tables">
<code class="literal">
CREATE TEMPORARY TABLES
</code>
</a>
privilege but is able to execute a definer-context stored
procedure that executes with the privileges of a user who does
have
<a class="link" href="privileges-provided.html#priv_create-temporary-tables">
<code class="literal">
CREATE TEMPORARY TABLES
</code>
</a>
and
that creates a temporary table. While the procedure executes,
the session uses the privileges of the defining user. After the
procedure returns, the effective privileges revert to those of
the current user, which can still see the temporary table and
perform any operation on it.
</p>
<p>
You cannot use
<code class="literal">
CREATE TEMPORARY TABLE ...
LIKE
</code>
to create an empty table based on the definition
of a table that resides in the
<code class="literal">
mysql
</code>
tablespace,
<code class="literal">
InnoDB
</code>
system tablespace
(
<code class="literal">
innodb_system
</code>
), or a general tablespace. The
tablespace definition for such a table includes a
<code class="literal">
TABLESPACE
</code>
attribute that defines the
tablespace where the table resides, and the aforementioned
tablespaces do not support temporary tables. To create a
temporary table based on the definition of such a table, use
this syntax instead:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa73478680"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">TEMPORARY</span> <span class="token keyword">TABLE</span> <em class="replaceable">new_tbl</em> <span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> <em class="replaceable">orig_tbl</em> <span class="token keyword">LIMIT</span> <span class="token number">0</span><span class="token punctuation">;</span></code></pre>
</div>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
Support for
<code class="literal">
TABLESPACE =
innodb_file_per_table
</code>
and
<code class="literal">
TABLESPACE =
innodb_temporary
</code>
clauses with
<a class="link" href="create-table.html" title="15.1.20 CREATE TABLE Statement">
<code class="literal">
CREATE TEMPORARY
TABLE
</code>
</a>
is deprecated; expect it to be removed in a
future version of MySQL.
</p>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/order-by-optimization.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="order-by-optimization">
</a>
10.2.1.16 ORDER BY Optimization
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045228990736">
</a>
<a class="indexterm" name="idm46045228989664">
</a>
<p>
This section describes when MySQL can use an index to satisfy
an
<code class="literal">
ORDER BY
</code>
clause, the
<code class="literal">
filesort
</code>
operation used when an index
cannot be used, and execution plan information available from
the optimizer about
<code class="literal">
ORDER BY
</code>
.
</p>
<p>
An
<code class="literal">
ORDER BY
</code>
with and without
<code class="literal">
LIMIT
</code>
may return rows in different orders,
as discussed in
<a class="xref" href="limit-optimization.html" title="10.2.1.19 LIMIT Query Optimization">
Section 10.2.1.19, “LIMIT Query Optimization”
</a>
.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="xref" href="order-by-optimization.html#order-by-index-use" title="Use of Indexes to Satisfy ORDER BY">
Use of Indexes to Satisfy ORDER BY
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="order-by-optimization.html#order-by-filesort" title="Use of filesort to Satisfy ORDER BY">
Use of filesort to Satisfy ORDER BY
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="order-by-optimization.html#order-by-optimizer-control" title="Influencing ORDER BY Optimization">
Influencing ORDER BY Optimization
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="order-by-optimization.html#order-by-diagnostic-information" title="ORDER BY Execution Plan Information Available">
ORDER BY Execution Plan Information Available
</a>
</p>
</li>
</ul>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="order-by-index-use">
</a>
Use of Indexes to Satisfy ORDER BY
</h5>
</div>
</div>
</div>
<p>
In some cases, MySQL may use an index to satisfy an
<code class="literal">
ORDER BY
</code>
clause and avoid the extra
sorting involved in performing a
<code class="literal">
filesort
</code>
operation.
</p>
<p>
The index may also be used even if the
<code class="literal">
ORDER
BY
</code>
does not match the index exactly, as long as
all unused portions of the index and all extra
<code class="literal">
ORDER BY
</code>
columns are constants in the
<code class="literal">
WHERE
</code>
clause. If the index does not
contain all columns accessed by the query, the index is used
only if index access is cheaper than other access methods.
</p>
<p>
Assuming that there is an index on
<code class="literal">
(
<em class="replaceable">
<code>
key_part1
</code>
</em>
,
<em class="replaceable">
<code>
key_part2
</code>
</em>
)
</code>
, the
following queries may use the index to resolve the
<code class="literal">
ORDER BY
</code>
part. Whether the optimizer
actually does so depends on whether reading the index is
more efficient than a table scan if columns not in the index
must also be read.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
In this query, the index on
<code class="literal">
(
<em class="replaceable">
<code>
key_part1
</code>
</em>
,
<em class="replaceable">
<code>
key_part2
</code>
</em>
)
</code>
enables
the optimizer to avoid sorting:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa89495672"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t1
<span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <em class="replaceable">key_part1</em><span class="token punctuation">,</span> <em class="replaceable">key_part2</em><span class="token punctuation">;</span></code></pre>
</div>
<p>
However, the query uses
<code class="literal">
SELECT *
</code>
,
which may select more columns than
<em class="replaceable">
<code>
key_part1
</code>
</em>
and
<em class="replaceable">
<code>
key_part2
</code>
</em>
. In that case,
scanning an entire index and looking up table rows to
find columns not in the index may be more expensive than
scanning the table and sorting the results. If so, the
optimizer probably does not use the index. If
<code class="literal">
SELECT *
</code>
selects only the index
columns, the index is used and sorting avoided.
</p>
<p>
If
<code class="literal">
t1
</code>
is an
<code class="literal">
InnoDB
</code>
table, the table primary key is implicitly part of the
index, and the index can be used to resolve the
<code class="literal">
ORDER BY
</code>
for this query:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa50965856"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <em class="replaceable">pk</em><span class="token punctuation">,</span> <em class="replaceable">key_part1</em><span class="token punctuation">,</span> <em class="replaceable">key_part2</em> <span class="token keyword">FROM</span> t1
<span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <em class="replaceable">key_part1</em><span class="token punctuation">,</span> <em class="replaceable">key_part2</em><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
In this query,
<em class="replaceable">
<code>
key_part1
</code>
</em>
is
constant, so all rows accessed through the index are in
<em class="replaceable">
<code>
key_part2
</code>
</em>
order, and an index
on
<code class="literal">
(
<em class="replaceable">
<code>
key_part1
</code>
</em>
,
<em class="replaceable">
<code>
key_part2
</code>
</em>
)
</code>
avoids
sorting if the
<code class="literal">
WHERE
</code>
clause is
selective enough to make an index range scan cheaper
than a table scan:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa6010430"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t1
<span class="token keyword">WHERE</span> <em class="replaceable">key_part1</em> <span class="token operator">=</span> <em class="replaceable">constant</em>
<span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <em class="replaceable">key_part2</em><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
In the next two queries, whether the index is used is
similar to the same queries without
<code class="literal">
DESC
</code>
shown previously:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa50470115"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t1
<span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <em class="replaceable">key_part1</em> <span class="token keyword">DESC</span><span class="token punctuation">,</span> <em class="replaceable">key_part2</em> <span class="token keyword">DESC</span><span class="token punctuation">;</span>
<span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t1
<span class="token keyword">WHERE</span> <em class="replaceable">key_part1</em> <span class="token operator">=</span> <em class="replaceable">constant</em>
<span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <em class="replaceable">key_part2</em> <span class="token keyword">DESC</span><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
Two columns in an
<code class="literal">
ORDER BY
</code>
can sort
in the same direction (both
<code class="literal">
ASC
</code>
, or
both
<code class="literal">
DESC
</code>
) or in opposite directions
(one
<code class="literal">
ASC
</code>
, one
<code class="literal">
DESC
</code>
). A condition for index use is
that the index must have the same homogeneity, but need
not have the same actual direction.
</p>
<p>
If a query mixes
<code class="literal">
ASC
</code>
and
<code class="literal">
DESC
</code>
, the optimizer can use an index
on the columns if the index also uses corresponding
mixed ascending and descending columns:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa8499702"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t1
<span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <em class="replaceable">key_part1</em> <span class="token keyword">DESC</span><span class="token punctuation">,</span> <em class="replaceable">key_part2</em> <span class="token keyword">ASC</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
The optimizer can use an index on
(
<em class="replaceable">
<code>
key_part1
</code>
</em>
,
<em class="replaceable">
<code>
key_part2
</code>
</em>
) if
<em class="replaceable">
<code>
key_part1
</code>
</em>
is descending and
<em class="replaceable">
<code>
key_part2
</code>
</em>
is ascending. It
can also use an index on those columns (with a backward
scan) if
<em class="replaceable">
<code>
key_part1
</code>
</em>
is
ascending and
<em class="replaceable">
<code>
key_part2
</code>
</em>
is
descending. See
<a class="xref" href="descending-indexes.html" title="10.3.13 Descending Indexes">
Section 10.3.13, “Descending Indexes”
</a>
.
</p>
</li>
<li class="listitem">
<p>
In the next two queries,
<em class="replaceable">
<code>
key_part1
</code>
</em>
is compared to a
constant. The index is used if the
<code class="literal">
WHERE
</code>
clause is selective enough to
make an index range scan cheaper than a table scan:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa29667233"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t1
<span class="token keyword">WHERE</span> <em class="replaceable">key_part1</em> <span class="token operator">></span> <em class="replaceable">constant</em>
<span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <em class="replaceable">key_part1</em> <span class="token keyword">ASC</span><span class="token punctuation">;</span>
<span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t1
<span class="token keyword">WHERE</span> <em class="replaceable">key_part1</em> <span class="token operator"><</span> <em class="replaceable">constant</em>
<span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <em class="replaceable">key_part1</em> <span class="token keyword">DESC</span><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
In the next query, the
<code class="literal">
ORDER BY
</code>
does
not name
<em class="replaceable">
<code>
key_part1
</code>
</em>
, but all
rows selected have a constant
<em class="replaceable">
<code>
key_part1
</code>
</em>
value, so the index
can still be used:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa61870906"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t1
<span class="token keyword">WHERE</span> <em class="replaceable">key_part1</em> <span class="token operator">=</span> <em class="replaceable">constant1</em> <span class="token operator">AND</span> <em class="replaceable">key_part2</em> <span class="token operator">></span> <em class="replaceable">constant2</em>
<span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <em class="replaceable">key_part2</em><span class="token punctuation">;</span></code></pre>
</div>
</li>
</ul>
</div>
<p>
In some cases, MySQL
<span class="emphasis">
<em>
cannot
</em>
</span>
use indexes
to resolve the
<code class="literal">
ORDER BY
</code>
, although it may
still use indexes to find the rows that match the
<code class="literal">
WHERE
</code>
clause. Examples:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
The query uses
<code class="literal">
ORDER BY
</code>
on different
indexes:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa51198785"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t1 <span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <em class="replaceable">key1</em><span class="token punctuation">,</span> <em class="replaceable">key2</em><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
The query uses
<code class="literal">
ORDER BY
</code>
on
nonconsecutive parts of an index:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa37305406"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t1 <span class="token keyword">WHERE</span> <em class="replaceable">key2</em><span class="token operator">=</span><em class="replaceable">constant</em> <span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <em class="replaceable">key1_part1</em><span class="token punctuation">,</span> <em class="replaceable">key1_part3</em><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
The index used to fetch the rows differs from the one
used in the
<code class="literal">
ORDER BY
</code>
:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa19645393"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t1 <span class="token keyword">WHERE</span> <em class="replaceable">key2</em><span class="token operator">=</span><em class="replaceable">constant</em> <span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <em class="replaceable">key1</em><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
The query uses
<code class="literal">
ORDER BY
</code>
with an
expression that includes terms other than the index
column name:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa8220560"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t1 <span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <span class="token function">ABS</span><span class="token punctuation">(</span><span class="token keyword"><em class="replaceable">key</em></span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t1 <span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <span class="token operator">-</span><span class="token keyword"><em class="replaceable">key</em></span><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
The query joins many tables, and the columns in the
<code class="literal">
ORDER BY
</code>
are not all from the first
nonconstant table that is used to retrieve rows. (This
is the first table in the
<a class="link" href="explain.html" title="15.8.2 EXPLAIN Statement">
<code class="literal">
EXPLAIN
</code>
</a>
output that does
not have a
<a class="link" href="explain-output.html#jointype_const">
<code class="literal">
const
</code>
</a>
join
type.)
</p>
</li>
<li class="listitem">
<p>
The query has different
<code class="literal">
ORDER BY
</code>
and
<code class="literal">
GROUP BY
</code>
expressions.
</p>
</li>
<li class="listitem">
<p>
There is an index on only a prefix of a column named in
the
<code class="literal">
ORDER BY
</code>
clause. In this case,
the index cannot be used to fully resolve the sort
order. For example, if only the first 10 bytes of a
<a class="link" href="char.html" title="13.3.2 The CHAR and VARCHAR Types">
<code class="literal">
CHAR(20)
</code>
</a>
column are
indexed, the index cannot distinguish values past the
10th byte and a
<code class="literal">
filesort
</code>
is needed.
</p>
</li>
<li class="listitem">
<p>
The index does not store rows in order. For example,
this is true for a
<code class="literal">
HASH
</code>
index in a
<code class="literal">
MEMORY
</code>
table.
</p>
</li>
</ul>
</div>
<p>
Availability of an index for sorting may be affected by the
use of column aliases. Suppose that the column
<code class="literal">
t1.a
</code>
is indexed. In this statement, the
name of the column in the select list is
<code class="literal">
a
</code>
. It refers to
<code class="literal">
t1.a
</code>
,
as does the reference to
<code class="literal">
a
</code>
in the
<code class="literal">
ORDER BY
</code>
, so the index on
<code class="literal">
t1.a
</code>
can be used:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa92354081"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> a <span class="token keyword">FROM</span> t1 <span class="token keyword">ORDER</span> <span class="token keyword">BY</span> a<span class="token punctuation">;</span></code></pre>
</div>
<p>
In this statement, the name of the column in the select list
is also
<code class="literal">
a
</code>
, but it is the alias name. It
refers to
<code class="literal">
ABS(a)
</code>
, as does the reference
to
<code class="literal">
a
</code>
in the
<code class="literal">
ORDER BY
</code>
,
so the index on
<code class="literal">
t1.a
</code>
cannot be used:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa38911553"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token function">ABS</span><span class="token punctuation">(</span>a<span class="token punctuation">)</span> <span class="token keyword">AS</span> a <span class="token keyword">FROM</span> t1 <span class="token keyword">ORDER</span> <span class="token keyword">BY</span> a<span class="token punctuation">;</span></code></pre>
</div>
<p>
In the following statement, the
<code class="literal">
ORDER BY
</code>
refers to a name that is not the name of a column in the
select list. But there is a column in
<code class="literal">
t1
</code>
named
<code class="literal">
a
</code>
, so the
<code class="literal">
ORDER
BY
</code>
refers to
<code class="literal">
t1.a
</code>
and the index
on
<code class="literal">
t1.a
</code>
can be used. (The resulting sort
order may be completely different from the order for
<code class="literal">
ABS(a)
</code>
, of course.)
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa56657388"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token function">ABS</span><span class="token punctuation">(</span>a<span class="token punctuation">)</span> <span class="token keyword">AS</span> b <span class="token keyword">FROM</span> t1 <span class="token keyword">ORDER</span> <span class="token keyword">BY</span> a<span class="token punctuation">;</span></code></pre>
</div>
<a class="indexterm" name="idm46045228872320">
</a>
<a class="indexterm" name="idm46045228870832">
</a>
<a class="indexterm" name="idm46045228869344">
</a>
<a class="indexterm" name="idm46045228867856">
</a>
<p>
Previously (MySQL 8.3 and lower),
<code class="literal">
GROUP BY
</code>
sorted implicitly under certain
conditions. In MySQL 8.4, that no longer
occurs, so specifying
<code class="literal">
ORDER BY NULL
</code>
at
the end to suppress implicit sorting (as was done
previously) is no longer necessary. However, query results
may differ from previous MySQL versions. To produce a given
sort order, provide an
<code class="literal">
ORDER BY
</code>
clause.
</p>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="order-by-filesort">
</a>
Use of filesort to Satisfy ORDER BY
</h5>
</div>
</div>
</div>
<a class="indexterm" name="idm46045228862528">
</a>
<a class="indexterm" name="idm46045228861488">
</a>
<p>
If an index cannot be used to satisfy an
<code class="literal">
ORDER
BY
</code>
clause, MySQL performs a
<code class="literal">
filesort
</code>
operation that reads table rows
and sorts them. A
<code class="literal">
filesort
</code>
constitutes an
extra sorting phase in query execution.
</p>
<p>
To obtain memory for
<code class="literal">
filesort
</code>
operations,
the optimizer allocates memory buffers incrementally as
needed, up to the size indicated by the
<a class="link" href="server-system-variables.html#sysvar_sort_buffer_size">
<code class="literal">
sort_buffer_size
</code>
</a>
system
variable. This enables users to set
<a class="link" href="server-system-variables.html#sysvar_sort_buffer_size">
<code class="literal">
sort_buffer_size
</code>
</a>
to larger
values to speed up larger sorts, without concern for
excessive memory use for small sorts. (This benefit may not
occur for multiple concurrent sorts on Windows, which has a
weak multithreaded
<code class="literal">
malloc
</code>
.)
</p>
<p>
A
<code class="literal">
filesort
</code>
operation uses temporary disk
files as necessary if the result set is too large to fit in
memory. Some types of queries are particularly suited to
completely in-memory
<code class="literal">
filesort
</code>
operations.
For example, the optimizer can use
<code class="literal">
filesort
</code>
to efficiently handle in memory,
without temporary files, the
<code class="literal">
ORDER BY
</code>
operation for queries (and subqueries) of the following
form:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa13090108"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token keyword">FROM</span> <em class="replaceable">single_table</em> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <em class="replaceable">non_index_column</em> <span class="token punctuation">[</span><span class="token keyword">DESC</span><span class="token punctuation">]</span> <span class="token keyword">LIMIT</span> <span class="token punctuation">[</span><em class="replaceable">M</em><span class="token punctuation">,</span><span class="token punctuation">]</span><em class="replaceable">N</em><span class="token punctuation">;</span></code></pre>
</div>
<p>
Such queries are common in web applications that display
only a few rows from a larger result set. Examples:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa28370023"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> col1<span class="token punctuation">,</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token keyword">FROM</span> t1 <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <span class="token keyword">name</span> <span class="token keyword">LIMIT</span> <span class="token number">10</span><span class="token punctuation">;</span>
<span class="token keyword">SELECT</span> col1<span class="token punctuation">,</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token keyword">FROM</span> t1 <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token keyword">ORDER</span> <span class="token keyword">BY</span> <span class="token function">RAND</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token keyword">LIMIT</span> <span class="token number">15</span><span class="token punctuation">;</span></code></pre>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="order-by-optimizer-control">
</a>
Influencing ORDER BY Optimization
</h5>
</div>
</div>
</div>
<p>
To increase
<code class="literal">
ORDER BY
</code>
speed, check whether
you can get MySQL to use indexes rather than an extra
sorting phase. If this is not possible, try the following
strategies:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Increase the
<a class="link" href="server-system-variables.html#sysvar_sort_buffer_size">
<code class="literal">
sort_buffer_size
</code>
</a>
variable value. Ideally, the value should be large
enough for the entire result set to fit in the sort
buffer (to avoid writes to disk and merge passes).
</p>
<p>
Take into account that the size of column values stored
in the sort buffer is affected by the
<a class="link" href="server-system-variables.html#sysvar_max_sort_length">
<code class="literal">
max_sort_length
</code>
</a>
system
variable value. For example, if tuples store values of
long string columns and you increase the value of
<a class="link" href="server-system-variables.html#sysvar_max_sort_length">
<code class="literal">
max_sort_length
</code>
</a>
, the
size of sort buffer tuples increases as well and may
require you to increase
<a class="link" href="server-system-variables.html#sysvar_sort_buffer_size">
<code class="literal">
sort_buffer_size
</code>
</a>
.
</p>
<p>
To monitor the number of merge passes (to merge
temporary files), check the
<a class="link" href="server-status-variables.html#statvar_Sort_merge_passes">
<code class="literal">
Sort_merge_passes
</code>
</a>
status variable.
</p>
</li>
<li class="listitem">
<p>
Increase the
<a class="link" href="server-system-variables.html#sysvar_read_rnd_buffer_size">
<code class="literal">
read_rnd_buffer_size
</code>
</a>
variable value so that more rows are read at a time.
</p>
</li>
<li class="listitem">
<p>
Change the
<a class="link" href="server-system-variables.html#sysvar_tmpdir">
<code class="literal">
tmpdir
</code>
</a>
system variable to point to a dedicated file system with
large amounts of free space. The variable value can list
several paths that are used in round-robin fashion; you
can use this feature to spread the load across several
directories. Separate the paths by colon characters
(
<code class="literal">
:
</code>
) on Unix and semicolon characters
(
<code class="literal">
;
</code>
) on Windows. The paths should name
directories in file systems located on different
<span class="emphasis">
<em>
physical
</em>
</span>
disks, not different
partitions on the same disk.
</p>
</li>
</ul>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="order-by-diagnostic-information">
</a>
ORDER BY Execution Plan Information Available
</h5>
</div>
</div>
</div>
<p>
With
<a class="link" href="explain.html" title="15.8.2 EXPLAIN Statement">
<code class="literal">
EXPLAIN
</code>
</a>
(see
<a class="xref" href="using-explain.html" title="10.8.1 Optimizing Queries with EXPLAIN">
Section 10.8.1, “Optimizing Queries with EXPLAIN”
</a>
), you can check whether
MySQL can use indexes to resolve an
<code class="literal">
ORDER
BY
</code>
clause:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
If the
<code class="literal">
Extra
</code>
column of
<a class="link" href="explain.html" title="15.8.2 EXPLAIN Statement">
<code class="literal">
EXPLAIN
</code>
</a>
output does not
contain
<code class="literal">
Using filesort
</code>
, the index is
used and a
<code class="literal">
filesort
</code>
is not performed.
</p>
</li>
<li class="listitem">
<p>
If the
<code class="literal">
Extra
</code>
column of
<a class="link" href="explain.html" title="15.8.2 EXPLAIN Statement">
<code class="literal">
EXPLAIN
</code>
</a>
output contains
<code class="literal">
Using filesort
</code>
, the index is not used
and a
<code class="literal">
filesort
</code>
is performed.
</p>
</li>
</ul>
</div>
<p>
In addition, if a
<code class="literal">
filesort
</code>
is performed,
optimizer trace output includes a
<code class="literal">
filesort_summary
</code>
block. For example:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-json"><div class="docs-select-all right" id="sa39076008"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-json"><span class="token property">"filesort_summary"</span><span class="token operator">:</span> <span class="token punctuation">{</span>
<span class="token property">"rows"</span><span class="token operator">:</span> <span class="token number">100</span><span class="token punctuation">,</span>
<span class="token property">"examined_rows"</span><span class="token operator">:</span> <span class="token number">100</span><span class="token punctuation">,</span>
<span class="token property">"number_of_tmp_files"</span><span class="token operator">:</span> <span class="token number">0</span><span class="token punctuation">,</span>
<span class="token property">"peak_memory_used"</span><span class="token operator">:</span> <span class="token number">25192</span><span class="token punctuation">,</span>
<span class="token property">"sort_mode"</span><span class="token operator">:</span> <span class="token string">"<sort_key, packed_additional_fields>"</span>
<span class="token punctuation">}</span></code></pre>
</div>
<p>
<code class="literal">
peak_memory_used
</code>
indicates the maximum
memory used at any one time during the sort. This is a value
up to but not necessarily as large as the value of the
<a class="link" href="server-system-variables.html#sysvar_sort_buffer_size">
<code class="literal">
sort_buffer_size
</code>
</a>
system
variable. The optimizer allocates sort-buffer memory
incrementally, beginning with a small amount and adding more
as necessary, up to
<code class="literal">
sort_buffer_size
</code>
bytes.)
</p>
<p>
The
<code class="literal">
sort_mode
</code>
value provides information
about the contents of tuples in the sort buffer:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
<sort_key, rowid>
</code>
: This
indicates that sort buffer tuples are pairs that contain
the sort key value and row ID of the original table row.
Tuples are sorted by sort key value and the row ID is
used to read the row from the table.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
<sort_key, additional_fields>
</code>
:
This indicates that sort buffer tuples contain the sort
key value and columns referenced by the query. Tuples
are sorted by sort key value and column values are read
directly from the tuple.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
<sort_key,
packed_additional_fields>
</code>
: Like the
previous variant, but the additional columns are packed
tightly together instead of using a fixed-length
encoding.
</p>
</li>
</ul>
</div>
<p>
<a class="link" href="explain.html" title="15.8.2 EXPLAIN Statement">
<code class="literal">
EXPLAIN
</code>
</a>
does not distinguish
whether the optimizer does or does not perform a
<code class="literal">
filesort
</code>
in memory. Use of an in-memory
<code class="literal">
filesort
</code>
can be seen in optimizer trace
output. Look for
<code class="literal">
filesort_priority_queue_optimization
</code>
. For
information about the optimizer trace, see
<a class="xref" href="optimizer-tracing.html" title="10.15 Tracing the Optimizer">
Section 10.15, “Tracing the Optimizer”
</a>
.
</p>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-limitations-resolved.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="mysql-cluster-limitations-resolved">
</a>
25.2.7.11 Previous NDB Cluster Issues Resolved in NDB Cluster 8.4
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045123116032">
</a>
<p>
A number of limitations and related issues that existed in
earlier versions of NDB Cluster have been resolved in NDB 8.4.
These are described briefly in the following list:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<b>
Issue now resolved...
</b>
Text...
</p>
<p>
More text...
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/create-event.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="create-event">
</a>
15.1.13 CREATE EVENT Statement
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045188279808">
</a>
<a class="indexterm" name="idm46045188278320">
</a>
<a class="indexterm" name="idm46045188276832">
</a>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa19569262"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span>
<span class="token punctuation">[</span><span class="token keyword">DEFINER</span> <span class="token operator">=</span> <span class="token keyword"><em class="replaceable">user</em></span><span class="token punctuation">]</span>
<span class="token keyword">EVENT</span>
<span class="token punctuation">[</span><span class="token keyword">IF</span> <span class="token operator">NOT</span> <span class="token keyword">EXISTS</span><span class="token punctuation">]</span>
<em class="replaceable">event_name</em>
<span class="token keyword">ON</span> <span class="token keyword">SCHEDULE</span> <span class="token keyword"><em class="replaceable">schedule</em></span>
<span class="token punctuation">[</span><span class="token keyword">ON</span> <span class="token keyword">COMPLETION</span> <span class="token punctuation">[</span><span class="token operator">NOT</span><span class="token punctuation">]</span> <span class="token keyword">PRESERVE</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">ENABLE</span> <span class="token operator">|</span> <span class="token keyword">DISABLE</span> <span class="token operator">|</span> <span class="token keyword">DISABLE</span> <span class="token keyword">ON</span> {<span class="token keyword">REPLICA</span> <span class="token operator">|</span> <span class="token keyword">SLAVE</span>}<span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">COMMENT</span> <span class="token string">'<em class="replaceable">string</em>'</span><span class="token punctuation">]</span>
<span class="token keyword">DO</span> <em class="replaceable">event_body</em><span class="token punctuation">;</span>
<span class="token keyword"><em class="replaceable">schedule</em></span>: {
<span class="token keyword">AT</span> <span class="token datatype"><em class="replaceable">timestamp</em></span> <span class="token punctuation">[</span><span class="token operator">+</span> <span class="token keyword">INTERVAL</span> <span class="token keyword"><em class="replaceable">interval</em></span><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span>
<span class="token operator">|</span> <span class="token keyword">EVERY</span> <span class="token keyword"><em class="replaceable">interval</em></span>
<span class="token punctuation">[</span><span class="token keyword">STARTS</span> <span class="token datatype"><em class="replaceable">timestamp</em></span> <span class="token punctuation">[</span><span class="token operator">+</span> <span class="token keyword">INTERVAL</span> <span class="token keyword"><em class="replaceable">interval</em></span><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">ENDS</span> <span class="token datatype"><em class="replaceable">timestamp</em></span> <span class="token punctuation">[</span><span class="token operator">+</span> <span class="token keyword">INTERVAL</span> <span class="token keyword"><em class="replaceable">interval</em></span><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">]</span>
}
<span class="token keyword"><em class="replaceable">interval</em></span>:
<em class="replaceable">quantity</em> {<span class="token datatype">YEAR</span> <span class="token operator">|</span> <span class="token keyword">QUARTER</span> <span class="token operator">|</span> <span class="token keyword">MONTH</span> <span class="token operator">|</span> <span class="token keyword">DAY</span> <span class="token operator">|</span> <span class="token keyword">HOUR</span> <span class="token operator">|</span> <span class="token keyword">MINUTE</span> <span class="token operator">|</span>
<span class="token keyword">WEEK</span> <span class="token operator">|</span> <span class="token keyword">SECOND</span> <span class="token operator">|</span> <span class="token keyword">YEAR_MONTH</span> <span class="token operator">|</span> <span class="token keyword">DAY_HOUR</span> <span class="token operator">|</span> <span class="token keyword">DAY_MINUTE</span> <span class="token operator">|</span>
<span class="token keyword">DAY_SECOND</span> <span class="token operator">|</span> <span class="token keyword">HOUR_MINUTE</span> <span class="token operator">|</span> <span class="token keyword">HOUR_SECOND</span> <span class="token operator">|</span> <span class="token keyword">MINUTE_SECOND</span>}</code></pre>
</div>
<p>
This statement creates and schedules a new event. The event does
not run unless the Event Scheduler is enabled. For information
about checking Event Scheduler status and enabling it if
necessary, see
<a class="xref" href="events-configuration.html" title="27.4.2 Event Scheduler Configuration">
Section 27.4.2, “Event Scheduler Configuration”
</a>
.
</p>
<p>
<a class="link" href="create-event.html" title="15.1.13 CREATE EVENT Statement">
<code class="literal">
CREATE EVENT
</code>
</a>
requires the
<a class="link" href="privileges-provided.html#priv_event">
<code class="literal">
EVENT
</code>
</a>
privilege for the schema in
which the event is to be created. If the
<code class="literal">
DEFINER
</code>
clause is present, the privileges
required depend on the
<em class="replaceable">
<code>
user
</code>
</em>
value, as
discussed in
<a class="xref" href="stored-objects-security.html" title="27.6 Stored Object Access Control">
Section 27.6, “Stored Object Access Control”
</a>
.
</p>
<p>
The minimum requirements for a valid
<a class="link" href="create-event.html" title="15.1.13 CREATE EVENT Statement">
<code class="literal">
CREATE
EVENT
</code>
</a>
statement are as follows:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
The keywords
<a class="link" href="create-event.html" title="15.1.13 CREATE EVENT Statement">
<code class="literal">
CREATE EVENT
</code>
</a>
plus
an event name, which uniquely identifies the event in a
database schema.
</p>
</li>
<li class="listitem">
<p>
An
<code class="literal">
ON SCHEDULE
</code>
clause, which determines
when and how often the event executes.
</p>
</li>
<li class="listitem">
<p>
A
<a class="link" href="do.html" title="15.2.3 DO Statement">
<code class="literal">
DO
</code>
</a>
clause, which contains the
SQL statement to be executed by an event.
</p>
</li>
</ul>
</div>
<p>
This is an example of a minimal
<a class="link" href="create-event.html" title="15.1.13 CREATE EVENT Statement">
<code class="literal">
CREATE
EVENT
</code>
</a>
statement:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa85567510"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">EVENT</span> myevent
<span class="token keyword">ON</span> <span class="token keyword">SCHEDULE</span> <span class="token keyword">AT</span> <span class="token keyword">CURRENT_TIMESTAMP</span> <span class="token operator">+</span> <span class="token keyword">INTERVAL</span> <span class="token number">1</span> <span class="token keyword">HOUR</span>
<span class="token keyword">DO</span>
<span class="token keyword">UPDATE</span> myschema<span class="token punctuation">.</span>mytable <span class="token keyword">SET</span> mycol <span class="token operator">=</span> mycol <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
The previous statement creates an event named
<code class="literal">
myevent
</code>
. This event executes once—one
hour following its creation—by running an SQL statement that
increments the value of the
<code class="literal">
myschema.mytable
</code>
table's
<code class="literal">
mycol
</code>
column by 1.
</p>
<p>
The
<em class="replaceable">
<code>
event_name
</code>
</em>
must be a valid MySQL
identifier with a maximum length of 64 characters. Event names are
not case-sensitive, so you cannot have two events named
<code class="literal">
myevent
</code>
and
<code class="literal">
MyEvent
</code>
in the
same schema. In general, the rules governing event names are the
same as those for names of stored routines. See
<a class="xref" href="identifiers.html" title="11.2 Schema Object Names">
Section 11.2, “Schema Object Names”
</a>
.
</p>
<p>
An event is associated with a schema. If no schema is indicated as
part of
<em class="replaceable">
<code>
event_name
</code>
</em>
, the default
(current) schema is assumed. To create an event in a specific
schema, qualify the event name with a schema using
<code class="literal">
<em class="replaceable">
<code>
schema_name
</code>
</em>
.
<em class="replaceable">
<code>
event_name
</code>
</em>
</code>
syntax.
</p>
<p>
The
<code class="literal">
DEFINER
</code>
clause specifies the MySQL account
to be used when checking access privileges at event execution
time. If the
<code class="literal">
DEFINER
</code>
clause is present, the
<em class="replaceable">
<code>
user
</code>
</em>
value should be a MySQL account
specified as
<code class="literal">
'
<em class="replaceable">
<code>
user_name
</code>
</em>
'@'
<em class="replaceable">
<code>
host_name
</code>
</em>
'
</code>
,
<a class="link" href="information-functions.html#function_current-user">
<code class="literal">
CURRENT_USER
</code>
</a>
, or
<a class="link" href="information-functions.html#function_current-user">
<code class="literal">
CURRENT_USER()
</code>
</a>
. The permitted
<em class="replaceable">
<code>
user
</code>
</em>
values depend on the privileges
you hold, as discussed in
<a class="xref" href="stored-objects-security.html" title="27.6 Stored Object Access Control">
Section 27.6, “Stored Object Access Control”
</a>
. Also see that section
for additional information about event security.
</p>
<p>
If the
<code class="literal">
DEFINER
</code>
clause is omitted, the default
definer is the user who executes the
<a class="link" href="create-event.html" title="15.1.13 CREATE EVENT Statement">
<code class="literal">
CREATE
EVENT
</code>
</a>
statement. This is the same as specifying
<code class="literal">
DEFINER = CURRENT_USER
</code>
explicitly.
</p>
<p>
Within an event body, the
<a class="link" href="information-functions.html#function_current-user">
<code class="literal">
CURRENT_USER
</code>
</a>
function returns the
account used to check privileges at event execution time, which is
the
<code class="literal">
DEFINER
</code>
user. For information about user
auditing within events, see
<a class="xref" href="account-activity-auditing.html" title="8.2.23 SQL-Based Account Activity Auditing">
Section 8.2.23, “SQL-Based Account Activity Auditing”
</a>
.
</p>
<p>
<code class="literal">
IF NOT EXISTS
</code>
has the same meaning for
<a class="link" href="create-event.html" title="15.1.13 CREATE EVENT Statement">
<code class="literal">
CREATE EVENT
</code>
</a>
as for
<a class="link" href="create-table.html" title="15.1.20 CREATE TABLE Statement">
<code class="literal">
CREATE TABLE
</code>
</a>
: If an event named
<em class="replaceable">
<code>
event_name
</code>
</em>
already exists in the same
schema, no action is taken, and no error results. (However, a
warning is generated in such cases.)
</p>
<p>
The
<code class="literal">
ON SCHEDULE
</code>
clause determines when, how
often, and for how long the
<em class="replaceable">
<code>
event_body
</code>
</em>
defined for the event repeats. This clause takes one of two forms:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
AT
<em class="replaceable">
<code>
timestamp
</code>
</em>
</code>
is
used for a one-time event. It specifies that the event
executes one time only at the date and time given by
<em class="replaceable">
<code>
timestamp
</code>
</em>
, which must include both
the date and time, or must be an expression that resolves to a
datetime value. You may use a value of either the
<a class="link" href="datetime.html" title="13.2.2 The DATE, DATETIME, and TIMESTAMP Types">
<code class="literal">
DATETIME
</code>
</a>
or
<a class="link" href="datetime.html" title="13.2.2 The DATE, DATETIME, and TIMESTAMP Types">
<code class="literal">
TIMESTAMP
</code>
</a>
type for this
purpose. If the date is in the past, a warning occurs, as
shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa88247920"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token function">NOW</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> NOW() <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 2006<span class="token punctuation">-</span>02<span class="token punctuation">-</span>10 23:59:01 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output">1 row in set (0.04 sec)</span>
<span class="token prompt">mysql></span> <span class="token keyword">CREATE</span> <span class="token keyword">EVENT</span> e_totals
<span class="token prompt"> -></span> <span class="token keyword">ON</span> <span class="token keyword">SCHEDULE</span> <span class="token keyword">AT</span> <span class="token string">'2006-02-10 23:59:00'</span>
<span class="token prompt"> -></span> <span class="token keyword">DO</span> <span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> test<span class="token punctuation">.</span>totals <span class="token keyword">VALUES</span> <span class="token punctuation">(</span><span class="token function">NOW</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output">Query OK, 0 rows affected, 1 warning (0.00 sec)</span>
<span class="token prompt">mysql></span> <span class="token keyword">SHOW</span> <span class="token keyword">WARNINGS</span>\G
<span class="token output"><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span> 1. row <span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span>
Level<span class="token punctuation">:</span> Note
Code<span class="token punctuation">:</span> 1588
Message<span class="token punctuation">:</span> Event execution time is in the past and ON COMPLETION NOT
PRESERVE is set. The event was dropped immediately after
creation.</span></code></pre>
</div>
<p>
<a class="link" href="create-event.html" title="15.1.13 CREATE EVENT Statement">
<code class="literal">
CREATE EVENT
</code>
</a>
statements which
are themselves invalid—for whatever reason—fail
with an error.
</p>
<p>
You may use
<a class="link" href="date-and-time-functions.html#function_current-timestamp">
<code class="literal">
CURRENT_TIMESTAMP
</code>
</a>
to specify the current date and time. In such a case, the
event acts as soon as it is created.
</p>
<p>
To create an event which occurs at some point in the future
relative to the current date and time—such as that
expressed by the phrase
<span class="quote">
“
<span class="quote">
three weeks from
now
</span>
”
</span>
—you can use the optional clause
<code class="literal">
+
INTERVAL
<em class="replaceable">
<code>
interval
</code>
</em>
</code>
. The
<em class="replaceable">
<code>
interval
</code>
</em>
portion consists of two
parts, a quantity and a unit of time, and follows the syntax
rules described in
<a class="xref" href="expressions.html#temporal-intervals" title="Temporal Intervals">
Temporal Intervals
</a>
,
except that you cannot use any units keywords that involving
microseconds when defining an event. With some interval types,
complex time units may be used. For example,
<span class="quote">
“
<span class="quote">
two
minutes and ten seconds
</span>
”
</span>
can be expressed as
<code class="literal">
+
INTERVAL '2:10' MINUTE_SECOND
</code>
.
</p>
<p>
You can also combine intervals. For example,
<code class="literal">
AT
CURRENT_TIMESTAMP + INTERVAL 3 WEEK + INTERVAL 2 DAY
</code>
is equivalent to
<span class="quote">
“
<span class="quote">
three weeks and two days from
now
</span>
”
</span>
. Each portion of such a clause must begin with
<code class="literal">
+ INTERVAL
</code>
.
</p>
</li>
<li class="listitem">
<p>
To repeat actions at a regular interval, use an
<code class="literal">
EVERY
</code>
clause. The
<code class="literal">
EVERY
</code>
keyword is followed by an
<em class="replaceable">
<code>
interval
</code>
</em>
as described in the previous discussion of the
<code class="literal">
AT
</code>
keyword. (
<code class="literal">
+ INTERVAL
</code>
is
<span class="emphasis">
<em>
not
</em>
</span>
used with
<code class="literal">
EVERY
</code>
.) For example,
<code class="literal">
EVERY 6
WEEK
</code>
means
<span class="quote">
“
<span class="quote">
every six weeks
</span>
”
</span>
.
</p>
<p>
Although
<code class="literal">
+ INTERVAL
</code>
clauses are not
permitted in an
<code class="literal">
EVERY
</code>
clause, you can use
the same complex time units permitted in a
<code class="literal">
+
INTERVAL
</code>
.
</p>
<p>
An
<code class="literal">
EVERY
</code>
clause may contain an optional
<code class="literal">
STARTS
</code>
clause.
<code class="literal">
STARTS
</code>
is
followed by a
<em class="replaceable">
<code>
timestamp
</code>
</em>
value that
indicates when the action should begin repeating, and may also
use
<code class="literal">
+ INTERVAL
<em class="replaceable">
<code>
interval
</code>
</em>
</code>
to specify an
amount of time
<span class="quote">
“
<span class="quote">
from now
</span>
”
</span>
. For example,
<code class="literal">
EVERY 3 MONTH STARTS CURRENT_TIMESTAMP + INTERVAL 1
WEEK
</code>
means
<span class="quote">
“
<span class="quote">
every three months, beginning one
week from now
</span>
”
</span>
. Similarly, you can express
<span class="quote">
“
<span class="quote">
every
two weeks, beginning six hours and fifteen minutes from
now
</span>
”
</span>
as
<code class="literal">
EVERY 2 WEEK STARTS CURRENT_TIMESTAMP
+ INTERVAL '6:15' HOUR_MINUTE
</code>
. Not specifying
<code class="literal">
STARTS
</code>
is the same as using
<code class="literal">
STARTS
CURRENT_TIMESTAMP
</code>
—that is, the action
specified for the event begins repeating immediately upon
creation of the event.
</p>
<p>
An
<code class="literal">
EVERY
</code>
clause may contain an optional
<code class="literal">
ENDS
</code>
clause. The
<code class="literal">
ENDS
</code>
keyword is followed by a
<em class="replaceable">
<code>
timestamp
</code>
</em>
value that tells MySQL when the event should stop repeating.
You may also use
<code class="literal">
+ INTERVAL
<em class="replaceable">
<code>
interval
</code>
</em>
</code>
with
<code class="literal">
ENDS
</code>
; for instance,
<code class="literal">
EVERY 12 HOUR
STARTS CURRENT_TIMESTAMP + INTERVAL 30 MINUTE ENDS
CURRENT_TIMESTAMP + INTERVAL 4 WEEK
</code>
is equivalent to
<span class="quote">
“
<span class="quote">
every twelve hours, beginning thirty minutes from now,
and ending four weeks from now
</span>
”
</span>
. Not using
<code class="literal">
ENDS
</code>
means that the event continues
executing indefinitely.
</p>
<p>
<code class="literal">
ENDS
</code>
supports the same syntax for complex
time units as
<code class="literal">
STARTS
</code>
does.
</p>
<p>
You may use
<code class="literal">
STARTS
</code>
,
<code class="literal">
ENDS
</code>
, both, or neither in an
<code class="literal">
EVERY
</code>
clause.
</p>
<p>
If a repeating event does not terminate within its scheduling
interval, the result may be multiple instances of the event
executing simultaneously. If this is undesirable, you should
institute a mechanism to prevent simultaneous instances. For
example, you could use the
<a class="link" href="locking-functions.html#function_get-lock">
<code class="literal">
GET_LOCK()
</code>
</a>
function, or row or
table locking.
</p>
</li>
</ul>
</div>
<p>
The
<code class="literal">
ON SCHEDULE
</code>
clause may use expressions
involving built-in MySQL functions and user variables to obtain
any of the
<em class="replaceable">
<code>
timestamp
</code>
</em>
or
<em class="replaceable">
<code>
interval
</code>
</em>
values which it contains. You
may not use stored functions or loadable functions in such
expressions, nor may you use any table references; however, you
may use
<code class="literal">
SELECT FROM DUAL
</code>
. This is true for both
<a class="link" href="create-event.html" title="15.1.13 CREATE EVENT Statement">
<code class="literal">
CREATE EVENT
</code>
</a>
and
<a class="link" href="alter-event.html" title="15.1.3 ALTER EVENT Statement">
<code class="literal">
ALTER EVENT
</code>
</a>
statements. References
to stored functions, loadable functions, and tables in such cases
are specifically not permitted, and fail with an error (see Bug
#22830).
</p>
<p>
Times in the
<code class="literal">
ON SCHEDULE
</code>
clause are interpreted
using the current session
<a class="link" href="server-system-variables.html#sysvar_time_zone">
<code class="literal">
time_zone
</code>
</a>
value. This becomes the
event time zone; that is, the time zone that is used for event
scheduling and is in effect within the event as it executes. These
times are converted to UTC and stored along with the event time
zone internally. This enables event execution to proceed as
defined regardless of any subsequent changes to the server time
zone or daylight saving time effects. For additional information
about representation of event times, see
<a class="xref" href="events-metadata.html" title="27.4.4 Event Metadata">
Section 27.4.4, “Event Metadata”
</a>
. See also
<a class="xref" href="show-events.html" title="15.7.7.19 SHOW EVENTS Statement">
Section 15.7.7.19, “SHOW EVENTS Statement”
</a>
, and
<a class="xref" href="information-schema-events-table.html" title="28.3.14 The INFORMATION_SCHEMA EVENTS Table">
Section 28.3.14, “The INFORMATION_SCHEMA EVENTS Table”
</a>
.
</p>
<p>
Normally, once an event has expired, it is immediately dropped.
You can override this behavior by specifying
<code class="literal">
ON
COMPLETION PRESERVE
</code>
. Using
<code class="literal">
ON COMPLETION NOT
PRESERVE
</code>
merely makes the default nonpersistent behavior
explicit.
</p>
<p>
You can create an event but prevent it from being active using the
<code class="literal">
DISABLE
</code>
keyword. Alternatively, you can use
<code class="literal">
ENABLE
</code>
to make explicit the default status,
which is active. This is most useful in conjunction with
<a class="link" href="alter-event.html" title="15.1.3 ALTER EVENT Statement">
<code class="literal">
ALTER EVENT
</code>
</a>
(see
<a class="xref" href="alter-event.html" title="15.1.3 ALTER EVENT Statement">
Section 15.1.3, “ALTER EVENT Statement”
</a>
).
</p>
<p>
A third value may also appear in place of
<code class="literal">
ENABLE
</code>
or
<code class="literal">
DISABLE
</code>
;
<code class="literal">
DISABLE ON REPLICA
</code>
is set for the status of an
event on a replica to indicate that the event was created on the
replication source server and replicated to the replica, but is
not executed on the replica. See
<a class="xref" href="replication-features-invoked.html" title="19.5.1.16 Replication of Invoked Features">
Section 19.5.1.16, “Replication of Invoked Features”
</a>
.
</p>
<p>
<code class="literal">
DISABLE ON REPLICA
</code>
replaces
<code class="literal">
DISABLE ON
SLAVE
</code>
, which is deprecated, and thus subject to removal
in a future version of MySQL.
</p>
<p>
You may supply a comment for an event using a
<code class="literal">
COMMENT
</code>
clause.
<em class="replaceable">
<code>
comment
</code>
</em>
may be any string of up to 64
characters that you wish to use for describing the event. The
comment text, being a string literal, must be surrounded by
quotation marks.
</p>
<p>
The
<a class="link" href="do.html" title="15.2.3 DO Statement">
<code class="literal">
DO
</code>
</a>
clause specifies an action
carried by the event, and consists of an SQL statement. Nearly any
valid MySQL statement that can be used in a stored routine can
also be used as the action statement for a scheduled event. (See
<a class="xref" href="stored-program-restrictions.html" title="27.8 Restrictions on Stored Programs">
Section 27.8, “Restrictions on Stored Programs”
</a>
.) For example, the
following event
<code class="literal">
e_hourly
</code>
deletes all rows from
the
<code class="literal">
sessions
</code>
table once per hour, where this
table is part of the
<code class="literal">
site_activity
</code>
schema:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa77594483"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">EVENT</span> e_hourly
<span class="token keyword">ON</span> <span class="token keyword">SCHEDULE</span>
<span class="token keyword">EVERY</span> <span class="token number">1</span> <span class="token keyword">HOUR</span>
<span class="token keyword">COMMENT</span> <span class="token string">'Clears out sessions table each hour.'</span>
<span class="token keyword">DO</span>
<span class="token keyword">DELETE</span> <span class="token keyword">FROM</span> site_activity<span class="token punctuation">.</span>sessions<span class="token punctuation">;</span></code></pre>
</div>
<p>
MySQL stores the
<a class="link" href="server-system-variables.html#sysvar_sql_mode">
<code class="literal">
sql_mode
</code>
</a>
system
variable setting in effect when an event is created or altered,
and always executes the event with this setting in force,
<span class="emphasis">
<em>
regardless of the current server SQL mode when the event
begins executing
</em>
</span>
.
</p>
<p>
A
<a class="link" href="create-event.html" title="15.1.13 CREATE EVENT Statement">
<code class="literal">
CREATE EVENT
</code>
</a>
statement that
contains an
<a class="link" href="alter-event.html" title="15.1.3 ALTER EVENT Statement">
<code class="literal">
ALTER EVENT
</code>
</a>
statement
in its
<a class="link" href="do.html" title="15.2.3 DO Statement">
<code class="literal">
DO
</code>
</a>
clause appears to
succeed; however, when the server attempts to execute the
resulting scheduled event, the execution fails with an error.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
Statements such as
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
or
<a class="link" href="show.html" title="15.7.7 SHOW Statements">
<code class="literal">
SHOW
</code>
</a>
that merely return a result
set have no effect when used in an event; the output from these
is not sent to the MySQL Monitor, nor is it stored anywhere.
However, you can use statements such as
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT ...
INTO
</code>
</a>
and
<a class="link" href="insert-select.html" title="15.2.7.1 INSERT ... SELECT Statement">
<code class="literal">
INSERT INTO ...
SELECT
</code>
</a>
that store a result. (See the next example in
this section for an instance of the latter.)
</p>
</div>
<p>
The schema to which an event belongs is the default schema for
table references in the
<a class="link" href="do.html" title="15.2.3 DO Statement">
<code class="literal">
DO
</code>
</a>
clause.
Any references to tables in other schemas must be qualified with
the proper schema name.
</p>
<p>
As with stored routines, you can use compound-statement syntax in
the
<a class="link" href="do.html" title="15.2.3 DO Statement">
<code class="literal">
DO
</code>
</a>
clause by using the
<code class="literal">
BEGIN
</code>
and
<code class="literal">
END
</code>
keywords, as
shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa38352100"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">delimiter</span> <span class="token operator">|</span>
<span class="token keyword">CREATE</span> <span class="token keyword">EVENT</span> e_daily
<span class="token keyword">ON</span> <span class="token keyword">SCHEDULE</span>
<span class="token keyword">EVERY</span> <span class="token number">1</span> <span class="token keyword">DAY</span>
<span class="token keyword">COMMENT</span> <span class="token string">'Saves total number of sessions then clears the table each day'</span>
<span class="token keyword">DO</span>
<span class="token keyword">BEGIN</span>
<span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> site_activity<span class="token punctuation">.</span>totals <span class="token punctuation">(</span><span class="token datatype">time</span><span class="token punctuation">,</span> total<span class="token punctuation">)</span>
<span class="token keyword">SELECT</span> <span class="token keyword">CURRENT_TIMESTAMP</span><span class="token punctuation">,</span> <span class="token function">COUNT</span><span class="token punctuation">(</span><span class="token operator">*</span><span class="token punctuation">)</span>
<span class="token keyword">FROM</span> site_activity<span class="token punctuation">.</span>sessions<span class="token punctuation">;</span>
<span class="token keyword">DELETE</span> <span class="token keyword">FROM</span> site_activity<span class="token punctuation">.</span>sessions<span class="token punctuation">;</span>
<span class="token keyword">END</span> <span class="token operator">|</span>
<span class="token keyword">delimiter</span> <span class="token punctuation">;</span></code></pre>
</div>
<p>
This example uses the
<code class="literal">
delimiter
</code>
command to
change the statement delimiter. See
<a class="xref" href="stored-programs-defining.html" title="27.1 Defining Stored Programs">
Section 27.1, “Defining Stored Programs”
</a>
.
</p>
<p>
More complex compound statements, such as those used in stored
routines, are possible in an event. This example uses local
variables, an error handler, and a flow control construct:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa95430080"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">delimiter</span> <span class="token operator">|</span>
<span class="token keyword">CREATE</span> <span class="token keyword">EVENT</span> e
<span class="token keyword">ON</span> <span class="token keyword">SCHEDULE</span>
<span class="token keyword">EVERY</span> <span class="token number">5</span> <span class="token keyword">SECOND</span>
<span class="token keyword">DO</span>
<span class="token keyword">BEGIN</span>
<span class="token keyword">DECLARE</span> v <span class="token datatype">INTEGER</span><span class="token punctuation">;</span>
<span class="token keyword">DECLARE</span> <span class="token keyword">CONTINUE</span> <span class="token keyword">HANDLER</span> <span class="token keyword">FOR</span> <span class="token keyword">SQLEXCEPTION</span> <span class="token keyword">BEGIN</span> <span class="token keyword">END</span><span class="token punctuation">;</span>
<span class="token keyword">SET</span> v <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span>
<span class="token keyword">WHILE</span> v <span class="token operator"><</span> <span class="token number">5</span> <span class="token keyword">DO</span>
<span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> t1 <span class="token keyword">VALUES</span> <span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">UPDATE</span> t2 <span class="token keyword">SET</span> s1 <span class="token operator">=</span> s1 <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">;</span>
<span class="token keyword">SET</span> v <span class="token operator">=</span> v <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">;</span>
<span class="token keyword">END</span> <span class="token keyword">WHILE</span><span class="token punctuation">;</span>
<span class="token keyword">END</span> <span class="token operator">|</span>
<span class="token keyword">delimiter</span> <span class="token punctuation">;</span></code></pre>
</div>
<p>
There is no way to pass parameters directly to or from events;
however, it is possible to invoke a stored routine with parameters
within an event:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa66877583"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">EVENT</span> e_call_myproc
<span class="token keyword">ON</span> <span class="token keyword">SCHEDULE</span>
<span class="token keyword">AT</span> <span class="token keyword">CURRENT_TIMESTAMP</span> <span class="token operator">+</span> <span class="token keyword">INTERVAL</span> <span class="token number">1</span> <span class="token keyword">DAY</span>
<span class="token keyword">DO</span> <span class="token keyword">CALL</span> myproc<span class="token punctuation">(</span><span class="token number">5</span><span class="token punctuation">,</span> <span class="token number">27</span><span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
If an event's definer has privileges sufficient to set global
system variables (see
<a class="xref" href="system-variable-privileges.html" title="7.1.9.1 System Variable Privileges">
Section 7.1.9.1, “System Variable Privileges”
</a>
), the event can read
and write global variables. As granting such privileges entails a
potential for abuse, extreme care must be taken in doing so.
</p>
<p>
Generally, any statements that are valid in stored routines may be
used for action statements executed by events. For more
information about statements permissible within stored routines,
see
<a class="xref" href="stored-routines-syntax.html" title="27.2.1 Stored Routine Syntax">
Section 27.2.1, “Stored Routine Syntax”
</a>
. It is not possible
to create an event as part of a stored routine or to create an
event by another event.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/metadata-locking.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="metadata-locking">
</a>
10.11.4 Metadata Locking
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045222708352">
</a>
<a class="indexterm" name="idm46045222707280">
</a>
<a class="indexterm" name="idm46045222705792">
</a>
<p>
MySQL uses metadata locking to manage concurrent access to
database objects and to ensure data consistency. Metadata
locking applies not just to tables, but also to schemas, stored
programs (procedures, functions, triggers, scheduled events),
tablespaces, user locks acquired with the
<a class="link" href="locking-functions.html#function_get-lock">
<code class="literal">
GET_LOCK()
</code>
</a>
function (see
<a class="xref" href="locking-functions.html" title="14.14 Locking Functions">
Section 14.14, “Locking Functions”
</a>
), and locks acquired with
the locking service described in
<a class="xref" href="locking-service.html" title="7.6.9.1 The Locking Service">
Section 7.6.9.1, “The Locking Service”
</a>
.
</p>
<p>
The Performance Schema
<a class="link" href="performance-schema-metadata-locks-table.html" title="29.12.13.3 The metadata_locks Table">
<code class="literal">
metadata_locks
</code>
</a>
table exposes
metadata lock information, which can be useful for seeing which
sessions hold locks, are blocked waiting for locks, and so
forth. For details, see
<a class="xref" href="performance-schema-metadata-locks-table.html" title="29.12.13.3 The metadata_locks Table">
Section 29.12.13.3, “The metadata_locks Table”
</a>
.
</p>
<p>
Metadata locking does involve some overhead, which increases as
query volume increases. Metadata contention increases the more
that multiple queries attempt to access the same objects.
</p>
<p>
Metadata locking is not a replacement for the table definition
cache, and its mutexes and locks differ from the
<code class="literal">
LOCK_open
</code>
mutex. The following discussion
provides some information about how metadata locking works.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="xref" href="metadata-locking.html#metadata-lock-acquisition" title="Metadata Lock Acquisition">
Metadata Lock Acquisition
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="metadata-locking.html#metadata-lock-release" title="Metadata Lock Release">
Metadata Lock Release
</a>
</p>
</li>
</ul>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="metadata-lock-acquisition">
</a>
Metadata Lock Acquisition
</h4>
</div>
</div>
</div>
<p>
If there are multiple waiters for a given lock, the
highest-priority lock request is satisfied first, with an
exception related to the
<a class="link" href="server-system-variables.html#sysvar_max_write_lock_count">
<code class="literal">
max_write_lock_count
</code>
</a>
system
variable. Write lock requests have higher priority than read
lock requests. However, if
<a class="link" href="server-system-variables.html#sysvar_max_write_lock_count">
<code class="literal">
max_write_lock_count
</code>
</a>
is set
to some low value (say, 10), read lock requests may be
preferred over pending write lock requests if the read lock
requests have already been passed over in favor of 10 write
lock requests. Normally this behavior does not occur because
<a class="link" href="server-system-variables.html#sysvar_max_write_lock_count">
<code class="literal">
max_write_lock_count
</code>
</a>
by
default has a very large value.
</p>
<p>
Statements acquire metadata locks one by one, not
simultaneously, and perform deadlock detection in the process.
</p>
<p>
DML statements normally acquire locks in the order in which
tables are mentioned in the statement.
</p>
<p>
DDL statements,
<a class="link" href="lock-tables.html" title="15.3.6 LOCK TABLES and UNLOCK TABLES Statements">
<code class="literal">
LOCK TABLES
</code>
</a>
,
and other similar statements try to reduce the number of
possible deadlocks between concurrent DDL statements by
acquiring locks on explicitly named tables in name order.
Locks might be acquired in a different order for implicitly
used tables (such as tables in foreign key relationships that
also must be locked).
</p>
<p>
For example,
<a class="link" href="rename-table.html" title="15.1.36 RENAME TABLE Statement">
<code class="literal">
RENAME TABLE
</code>
</a>
is a
DDL statement that acquires locks in name order:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
This
<a class="link" href="rename-table.html" title="15.1.36 RENAME TABLE Statement">
<code class="literal">
RENAME TABLE
</code>
</a>
statement
renames
<code class="literal">
tbla
</code>
to something else, and
renames
<code class="literal">
tblc
</code>
to
<code class="literal">
tbla
</code>
:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa51532940"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">RENAME</span> <span class="token keyword">TABLE</span> tbla <span class="token keyword">TO</span> tbld<span class="token punctuation">,</span> tblc <span class="token keyword">TO</span> tbla<span class="token punctuation">;</span></code></pre>
</div>
<p>
The statement acquires metadata locks, in order, on
<code class="literal">
tbla
</code>
,
<code class="literal">
tblc
</code>
, and
<code class="literal">
tbld
</code>
(because
<code class="literal">
tbld
</code>
follows
<code class="literal">
tblc
</code>
in name order):
</p>
</li>
<li class="listitem">
<p>
This slightly different statement also renames
<code class="literal">
tbla
</code>
to something else, and renames
<code class="literal">
tblc
</code>
to
<code class="literal">
tbla
</code>
:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa63221648"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">RENAME</span> <span class="token keyword">TABLE</span> tbla <span class="token keyword">TO</span> tblb<span class="token punctuation">,</span> tblc <span class="token keyword">TO</span> tbla<span class="token punctuation">;</span></code></pre>
</div>
<p>
In this case, the statement acquires metadata locks, in
order, on
<code class="literal">
tbla
</code>
,
<code class="literal">
tblb
</code>
, and
<code class="literal">
tblc
</code>
(because
<code class="literal">
tblb
</code>
precedes
<code class="literal">
tblc
</code>
in name order):
</p>
</li>
</ul>
</div>
<p>
Both statements acquire locks on
<code class="literal">
tbla
</code>
and
<code class="literal">
tblc
</code>
, in that order, but differ in whether
the lock on the remaining table name is acquired before or
after
<code class="literal">
tblc
</code>
.
</p>
<p>
Metadata lock acquisition order can make a difference in
operation outcome when multiple transactions execute
concurrently, as the following example illustrates.
</p>
<p>
Begin with two tables
<code class="literal">
x
</code>
and
<code class="literal">
x_new
</code>
that have identical structure. Three
clients issue statements that involve these tables:
</p>
<p>
Client 1:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa71695431"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">LOCK</span> <span class="token keyword">TABLE</span> x <span class="token keyword">WRITE</span><span class="token punctuation">,</span> x_new <span class="token keyword">WRITE</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
The statement requests and acquires write locks in name order
on
<code class="literal">
x
</code>
and
<code class="literal">
x_new
</code>
.
</p>
<p>
Client 2:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa25439219"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> x <span class="token keyword">VALUES</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
The statement requests and blocks waiting for a write lock on
<code class="literal">
x
</code>
.
</p>
<p>
Client 3:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa99460770"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">RENAME</span> <span class="token keyword">TABLE</span> x <span class="token keyword">TO</span> x_old<span class="token punctuation">,</span> x_new <span class="token keyword">TO</span> x<span class="token punctuation">;</span></code></pre>
</div>
<p>
The statement requests exclusive locks in name order on
<code class="literal">
x
</code>
,
<code class="literal">
x_new
</code>
, and
<code class="literal">
x_old
</code>
, but blocks waiting for the lock on
<code class="literal">
x
</code>
.
</p>
<p>
Client 1:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa90821867"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UNLOCK</span> <span class="token keyword">TABLES</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
The statement releases the write locks on
<code class="literal">
x
</code>
and
<code class="literal">
x_new
</code>
. The exclusive lock request for
<code class="literal">
x
</code>
by Client 3 has higher priority than the
write lock request by Client 2, so Client 3 acquires its lock
on
<code class="literal">
x
</code>
, then also on
<code class="literal">
x_new
</code>
and
<code class="literal">
x_old
</code>
, performs the renaming, and
releases its locks. Client 2 then acquires its lock on
<code class="literal">
x
</code>
, performs the insert, and releases its
lock.
</p>
<p>
Lock acquisition order results in the
<a class="link" href="rename-table.html" title="15.1.36 RENAME TABLE Statement">
<code class="literal">
RENAME TABLE
</code>
</a>
executing before
the
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
. The
<code class="literal">
x
</code>
into which the insert occurs is the table
that was named
<code class="literal">
x_new
</code>
when Client 2 issued
the insert and was renamed to
<code class="literal">
x
</code>
by Client
3:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa46326642"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> x<span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> i <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> x_old<span class="token punctuation">;</span>
<span class="token output">Empty set (0.01 sec)</span></code></pre>
</div>
<p>
Now begin instead with tables named
<code class="literal">
x
</code>
and
<code class="literal">
new_x
</code>
that have identical structure. Again,
three clients issue statements that involve these tables:
</p>
<p>
Client 1:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa70394209"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">LOCK</span> <span class="token keyword">TABLE</span> x <span class="token keyword">WRITE</span><span class="token punctuation">,</span> new_x <span class="token keyword">WRITE</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
The statement requests and acquires write locks in name order
on
<code class="literal">
new_x
</code>
and
<code class="literal">
x
</code>
.
</p>
<p>
Client 2:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa12225078"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> x <span class="token keyword">VALUES</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
The statement requests and blocks waiting for a write lock on
<code class="literal">
x
</code>
.
</p>
<p>
Client 3:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa92475680"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">RENAME</span> <span class="token keyword">TABLE</span> x <span class="token keyword">TO</span> old_x<span class="token punctuation">,</span> new_x <span class="token keyword">TO</span> x<span class="token punctuation">;</span></code></pre>
</div>
<p>
The statement requests exclusive locks in name order on
<code class="literal">
new_x
</code>
,
<code class="literal">
old_x
</code>
, and
<code class="literal">
x
</code>
, but blocks waiting for the lock on
<code class="literal">
new_x
</code>
.
</p>
<p>
Client 1:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa60939175"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UNLOCK</span> <span class="token keyword">TABLES</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
The statement releases the write locks on
<code class="literal">
x
</code>
and
<code class="literal">
new_x
</code>
. For
<code class="literal">
x
</code>
, the
only pending request is by Client 2, so Client 2 acquires its
lock, performs the insert, and releases the lock. For
<code class="literal">
new_x
</code>
, the only pending request is by
Client 3, which is permitted to acquire that lock (and also
the lock on
<code class="literal">
old_x
</code>
). The rename operation
still blocks for the lock on
<code class="literal">
x
</code>
until the
Client 2 insert finishes and releases its lock. Then Client 3
acquires the lock on
<code class="literal">
x
</code>
, performs the
rename, and releases its lock.
</p>
<p>
In this case, lock acquisition order results in the
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
executing before the
<a class="link" href="rename-table.html" title="15.1.36 RENAME TABLE Statement">
<code class="literal">
RENAME TABLE
</code>
</a>
. The
<code class="literal">
x
</code>
into which the insert occurs is the
original
<code class="literal">
x
</code>
, now renamed to
<code class="literal">
old_x
</code>
by the rename operation:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa63511930"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> x<span class="token punctuation">;</span>
<span class="token output">Empty set (0.01 sec)</span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> old_x<span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> i <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
<p>
If order of lock acquisition in concurrent statements makes a
difference to an application in operation outcome, as in the
preceding example, you may be able to adjust the table names
to affect the order of lock acquisition.
</p>
<a class="indexterm" name="idm46045222606912">
</a>
<p>
Metadata locks are extended, as necessary, to tables related
by a foreign key constraint to prevent conflicting DML and DDL
operations from executing concurrently on the related tables.
When updating a parent table, a metadata lock is taken on the
child table while updating foreign key metadata. Foreign key
metadata is owned by the child table.
</p>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="metadata-lock-release">
</a>
Metadata Lock Release
</h4>
</div>
</div>
</div>
<p>
To ensure transaction serializability, the server must not
permit one session to perform a data definition language (DDL)
statement on a table that is used in an uncompleted explicitly
or implicitly started transaction in another session. The
server achieves this by acquiring metadata locks on tables
used within a transaction and deferring release of those locks
until the transaction ends. A metadata lock on a table
prevents changes to the table's structure. This locking
approach has the implication that a table that is being used
by a transaction within one session cannot be used in DDL
statements by other sessions until the transaction ends.
</p>
<p>
This principle applies not only to transactional tables, but
also to nontransactional tables. Suppose that a session begins
a transaction that uses transactional table
<code class="literal">
t
</code>
and nontransactional table
<code class="literal">
nt
</code>
as follows:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa22891176"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">START</span> <span class="token keyword">TRANSACTION</span><span class="token punctuation">;</span>
<span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> t<span class="token punctuation">;</span>
<span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> nt<span class="token punctuation">;</span></code></pre>
</div>
<p>
The server holds metadata locks on both
<code class="literal">
t
</code>
and
<code class="literal">
nt
</code>
until the transaction ends. If
another session attempts a DDL or write lock operation on
either table, it blocks until metadata lock release at
transaction end. For example, a second session blocks if it
attempts any of these operations:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa31348119"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">DROP</span> <span class="token keyword">TABLE</span> t<span class="token punctuation">;</span>
<span class="token keyword">ALTER</span> <span class="token keyword">TABLE</span> t <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">;</span>
<span class="token keyword">DROP</span> <span class="token keyword">TABLE</span> nt<span class="token punctuation">;</span>
<span class="token keyword">ALTER</span> <span class="token keyword">TABLE</span> nt <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">;</span>
<span class="token keyword">LOCK</span> <span class="token keyword">TABLE</span> t <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token keyword">WRITE</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
The same behavior applies for The
<a class="link" href="lock-tables.html" title="15.3.6 LOCK TABLES and UNLOCK TABLES Statements">
<code class="literal">
LOCK TABLES ...
READ
</code>
</a>
. That is, explicitly or implicitly started
transactions that update any table (transactional or
nontransactional) block and are blocked by
<code class="literal">
LOCK
TABLES ... READ
</code>
for that table.
</p>
<p>
If the server acquires metadata locks for a statement that is
syntactically valid but fails during execution, it does not
release the locks early. Lock release is still deferred to the
end of the transaction because the failed statement is written
to the binary log and the locks protect log consistency.
</p>
<p>
In autocommit mode, each statement is in effect a complete
transaction, so metadata locks acquired for the statement are
held only to the end of the statement.
</p>
<p>
Metadata locks acquired during a
<a class="link" href="prepare.html" title="15.5.1 PREPARE Statement">
<code class="literal">
PREPARE
</code>
</a>
statement are released
once the statement has been prepared, even if preparation
occurs within a multiple-statement transaction.
</p>
<p>
For XA transactions in
<code class="literal">
PREPARED
</code>
state,
metadata locks are maintained across client disconnects and
server restarts, until an
<a class="link" href="xa.html" title="15.3.8 XA Transactions">
<code class="literal">
XA COMMIT
</code>
</a>
or
<a class="link" href="xa.html" title="15.3.8 XA Transactions">
<code class="literal">
XA ROLLBACK
</code>
</a>
is
executed.
</p>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/charset-cp932.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="charset-cp932">
</a>
12.10.7.1 The cp932 Character Set
</h4>
</div>
</div>
</div>
<p>
<span class="bold">
<strong>
Why is
<code class="literal">
cp932
</code>
needed?
</strong>
</span>
</p>
<p>
In MySQL, the
<code class="literal">
sjis
</code>
character set
corresponds to the
<code class="literal">
Shift_JIS
</code>
character set
defined by IANA, which supports JIS X0201 and JIS X0208
characters. (See
<a class="ulink" href="http://www.iana.org/assignments/character-sets" target="_blank">
http://www.iana.org/assignments/character-sets
</a>
.)
</p>
<p>
However, the meaning of
<span class="quote">
“
<span class="quote">
SHIFT JIS
</span>
”
</span>
as a
descriptive term has become very vague and it often includes
the extensions to
<code class="literal">
Shift_JIS
</code>
that are
defined by various vendors.
</p>
<p>
For example,
<span class="quote">
“
<span class="quote">
SHIFT JIS
</span>
”
</span>
used in Japanese Windows
environments is a Microsoft extension of
<code class="literal">
Shift_JIS
</code>
and its exact name is
<code class="literal">
Microsoft Windows Codepage : 932
</code>
or
<code class="literal">
cp932
</code>
. In addition to the characters
supported by
<code class="literal">
Shift_JIS
</code>
,
<code class="literal">
cp932
</code>
supports extension characters such as
NEC special characters, NEC selected—IBM extended
characters, and IBM selected characters.
</p>
<p>
Many Japanese users have experienced problems using these
extension characters. These problems stem from the following
factors:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
MySQL automatically converts character sets.
</p>
</li>
<li class="listitem">
<p>
Character sets are converted using Unicode
(
<code class="literal">
ucs2
</code>
).
</p>
</li>
<li class="listitem">
<p>
The
<code class="literal">
sjis
</code>
character set does not support
the conversion of these extension characters.
</p>
</li>
<li class="listitem">
<p>
There are several conversion rules from so-called
<span class="quote">
“
<span class="quote">
SHIFT JIS
</span>
”
</span>
to Unicode, and some characters
are converted to Unicode differently depending on the
conversion rule. MySQL supports only one of these rules
(described later).
</p>
</li>
</ul>
</div>
<p>
The MySQL
<code class="literal">
cp932
</code>
character set is designed
to solve these problems.
</p>
<p>
Because MySQL supports character set conversion, it is
important to separate IANA
<code class="literal">
Shift_JIS
</code>
and
<code class="literal">
cp932
</code>
into two different character sets
because they provide different conversion rules.
</p>
<p>
<span class="bold">
<strong>
How does
<code class="literal">
cp932
</code>
differ
from
<code class="literal">
sjis
</code>
?
</strong>
</span>
</p>
<p>
The
<code class="literal">
cp932
</code>
character set differs from
<code class="literal">
sjis
</code>
in the following ways:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
cp932
</code>
supports NEC special characters,
NEC selected—IBM extended characters, and IBM
selected characters.
</p>
</li>
<li class="listitem">
<p>
Some
<code class="literal">
cp932
</code>
characters have two
different code points, both of which convert to the same
Unicode code point. When converting from Unicode back to
<code class="literal">
cp932
</code>
, one of the code points must be
selected. For this
<span class="quote">
“
<span class="quote">
round trip conversion,
</span>
”
</span>
the rule recommended by Microsoft is used. (See
<a class="ulink" href="http://support.microsoft.com/kb/170559/EN-US/" target="_blank">
http://support.microsoft.com/kb/170559/EN-US/
</a>
.)
</p>
<p>
The conversion rule works like this:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
If the character is in both JIS X 0208 and NEC special
characters, use the code point of JIS X 0208.
</p>
</li>
<li class="listitem">
<p>
If the character is in both NEC special characters and
IBM selected characters, use the code point of NEC
special characters.
</p>
</li>
<li class="listitem">
<p>
If the character is in both IBM selected characters
and NEC selected—IBM extended characters, use
the code point of IBM extended characters.
</p>
</li>
</ul>
</div>
<p>
The table shown at
<a class="ulink" href="https://msdn.microsoft.com/en-us/goglobal/cc305152.aspx" target="_blank">
https://msdn.microsoft.com/en-us/goglobal/cc305152.aspx
</a>
provides information about the Unicode values of
<code class="literal">
cp932
</code>
characters. For
<code class="literal">
cp932
</code>
table entries with characters
under which a four-digit number appears, the number
represents the corresponding Unicode
(
<code class="literal">
ucs2
</code>
) encoding. For table entries with
an underlined two-digit value appears, there is a range of
<code class="literal">
cp932
</code>
character values that begin with
those two digits. Clicking such a table entry takes you to
a page that displays the Unicode value for each of the
<code class="literal">
cp932
</code>
characters that begin with those
digits.
</p>
<p>
The following links are of special interest. They
correspond to the encodings for the following sets of
characters:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
NEC special characters (lead byte
<code class="literal">
0x87
</code>
):
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-html"><div class="docs-select-all right" id="sa81478078"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-html">https://msdn.microsoft.com/en-us/goglobal/gg674964</code></pre>
</div>
</li>
<li class="listitem">
<p>
NEC selected—IBM extended characters (lead byte
<code class="literal">
0xED
</code>
and
<code class="literal">
0xEE
</code>
):
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-html"><div class="docs-select-all right" id="sa44540478"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-html">https://msdn.microsoft.com/en-us/goglobal/gg671837
https://msdn.microsoft.com/en-us/goglobal/gg671838</code></pre>
</div>
</li>
<li class="listitem">
<p>
IBM selected characters (lead byte
<code class="literal">
0xFA
</code>
,
<code class="literal">
0xFB
</code>
,
<code class="literal">
0xFC
</code>
):
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-html"><div class="docs-select-all right" id="sa16524381"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-html">https://msdn.microsoft.com/en-us/goglobal/gg671839
https://msdn.microsoft.com/en-us/goglobal/gg671840
https://msdn.microsoft.com/en-us/goglobal/gg671841</code></pre>
</div>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
<code class="literal">
cp932
</code>
supports conversion of
user-defined characters in combination with
<code class="literal">
eucjpms
</code>
, and solves the problems with
<code class="literal">
sjis
</code>
/
<code class="literal">
ujis
</code>
conversion. For details, please refer to
<a class="ulink" href="http://www.sljfaq.org/afaq/encodings.html" target="_blank">
http://www.sljfaq.org/afaq/encodings.html
</a>
.
</p>
</li>
</ul>
</div>
<p>
For some characters, conversion to and from
<code class="literal">
ucs2
</code>
is different for
<code class="literal">
sjis
</code>
and
<code class="literal">
cp932
</code>
. The
following tables illustrate these differences.
</p>
<p>
Conversion to
<code class="literal">
ucs2
</code>
:
</p>
<div class="informaltable">
<table summary="sjis/cp932 values and the difference between sjis to ucs2 conversion and cp932 to ucs2 conversion.">
<colgroup>
<col style="width: 33%"/>
<col style="width: 33%"/>
<col style="width: 33%"/>
</colgroup>
<thead>
<tr>
<th scope="col">
<code class="literal">
sjis
</code>
/
<code class="literal">
cp932
</code>
Value
</th>
<th scope="col">
<code class="literal">
sjis
</code>
->
<code class="literal">
ucs2
</code>
Conversion
</th>
<th scope="col">
<code class="literal">
cp932
</code>
->
<code class="literal">
ucs2
</code>
Conversion
</th>
</tr>
</thead>
<tbody>
<tr>
<th scope="row">
5C
</th>
<td>
005C
</td>
<td>
005C
</td>
</tr>
<tr>
<th scope="row">
7E
</th>
<td>
007E
</td>
<td>
007E
</td>
</tr>
<tr>
<th scope="row">
815C
</th>
<td>
2015
</td>
<td>
2015
</td>
</tr>
<tr>
<th scope="row">
815F
</th>
<td>
005C
</td>
<td>
FF3C
</td>
</tr>
<tr>
<th scope="row">
8160
</th>
<td>
301C
</td>
<td>
FF5E
</td>
</tr>
<tr>
<th scope="row">
8161
</th>
<td>
2016
</td>
<td>
2225
</td>
</tr>
<tr>
<th scope="row">
817C
</th>
<td>
2212
</td>
<td>
FF0D
</td>
</tr>
<tr>
<th scope="row">
8191
</th>
<td>
00A2
</td>
<td>
FFE0
</td>
</tr>
<tr>
<th scope="row">
8192
</th>
<td>
00A3
</td>
<td>
FFE1
</td>
</tr>
<tr>
<th scope="row">
81CA
</th>
<td>
00AC
</td>
<td>
FFE2
</td>
</tr>
</tbody>
</table>
</div>
<div class="informaltable">
<table cellpadding="0" cellspacing="0" style="position: fixed; top: 0px; display: none; left: 401px; width: 558px;">
<thead>
<tr>
<th scope="col" style="width: 185.719px;">
<code class="literal">
sjis
</code>
/
<code class="literal">
cp932
</code>
Value
</th>
<th scope="col" style="width: 185.719px;">
<code class="literal">
sjis
</code>
->
<code class="literal">
ucs2
</code>
Conversion
</th>
<th scope="col" style="width: 185.75px;">
<code class="literal">
cp932
</code>
->
<code class="literal">
ucs2
</code>
Conversion
</th>
</tr>
</thead>
</table>
</div>
<p>
Conversion from
<code class="literal">
ucs2
</code>
:
</p>
<div class="informaltable">
<table summary="ucs2 values and the difference between ucs2 to sjis conversion and ucs2 to cp932 conversion.">
<colgroup>
<col style="width: 33%"/>
<col style="width: 33%"/>
<col style="width: 33%"/>
</colgroup>
<thead>
<tr>
<th scope="col">
<code class="literal">
ucs2
</code>
value
</th>
<th scope="col">
<code class="literal">
ucs2
</code>
->
<code class="literal">
sjis
</code>
Conversion
</th>
<th scope="col">
<code class="literal">
ucs2
</code>
->
<code class="literal">
cp932
</code>
Conversion
</th>
</tr>
</thead>
<tbody>
<tr>
<th scope="row">
005C
</th>
<td>
815F
</td>
<td>
5C
</td>
</tr>
<tr>
<th scope="row">
007E
</th>
<td>
7E
</td>
<td>
7E
</td>
</tr>
<tr>
<th scope="row">
00A2
</th>
<td>
8191
</td>
<td>
3F
</td>
</tr>
<tr>
<th scope="row">
00A3
</th>
<td>
8192
</td>
<td>
3F
</td>
</tr>
<tr>
<th scope="row">
00AC
</th>
<td>
81CA
</td>
<td>
3F
</td>
</tr>
<tr>
<th scope="row">
2015
</th>
<td>
815C
</td>
<td>
815C
</td>
</tr>
<tr>
<th scope="row">
2016
</th>
<td>
8161
</td>
<td>
3F
</td>
</tr>
<tr>
<th scope="row">
2212
</th>
<td>
817C
</td>
<td>
3F
</td>
</tr>
<tr>
<th scope="row">
2225
</th>
<td>
3F
</td>
<td>
8161
</td>
</tr>
<tr>
<th scope="row">
301C
</th>
<td>
8160
</td>
<td>
3F
</td>
</tr>
<tr>
<th scope="row">
FF0D
</th>
<td>
3F
</td>
<td>
817C
</td>
</tr>
<tr>
<th scope="row">
FF3C
</th>
<td>
3F
</td>
<td>
815F
</td>
</tr>
<tr>
<th scope="row">
FF5E
</th>
<td>
3F
</td>
<td>
8160
</td>
</tr>
<tr>
<th scope="row">
FFE0
</th>
<td>
3F
</td>
<td>
8191
</td>
</tr>
<tr>
<th scope="row">
FFE1
</th>
<td>
3F
</td>
<td>
8192
</td>
</tr>
<tr>
<th scope="row">
FFE2
</th>
<td>
3F
</td>
<td>
81CA
</td>
</tr>
</tbody>
</table>
</div>
<div class="informaltable">
<table cellpadding="0" cellspacing="0" style="position: fixed; top: 0px; display: none; left: 401px; width: 558px;">
<thead>
<tr>
<th scope="col" style="width: 185.719px;">
<code class="literal">
ucs2
</code>
value
</th>
<th scope="col" style="width: 185.719px;">
<code class="literal">
ucs2
</code>
->
<code class="literal">
sjis
</code>
Conversion
</th>
<th scope="col" style="width: 185.75px;">
<code class="literal">
ucs2
</code>
->
<code class="literal">
cp932
</code>
Conversion
</th>
</tr>
</thead>
</table>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/drop-event.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="drop-event">
</a>
15.1.25 DROP EVENT Statement
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045183471424">
</a>
<a class="indexterm" name="idm46045183470352">
</a>
<a class="indexterm" name="idm46045183468864">
</a>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa75626466"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">DROP</span> <span class="token keyword">EVENT</span> <span class="token punctuation">[</span><span class="token keyword">IF</span> <span class="token keyword">EXISTS</span><span class="token punctuation">]</span> <em class="replaceable">event_name</em></code></pre>
</div>
<p>
This statement drops the event named
<em class="replaceable">
<code>
event_name
</code>
</em>
. The event immediately
ceases being active, and is deleted completely from the server.
</p>
<p>
If the event does not exist, the error
<span class="errortext">
ERROR 1517
(HY000): Unknown event
'
<em class="replaceable">
<code>
event_name
</code>
</em>
'
</span>
results. You
can override this and cause the statement to generate a warning
for nonexistent events instead using
<code class="literal">
IF EXISTS
</code>
.
</p>
<p>
This statement requires the
<a class="link" href="privileges-provided.html#priv_event">
<code class="literal">
EVENT
</code>
</a>
privilege for the schema to which the event to be dropped belongs.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/replication-gtids-restrictions.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="replication-gtids-restrictions">
</a>
19.1.3.7 Restrictions on Replication with GTIDs
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045145817456">
</a>
<p>
Because GTID-based replication is dependent on transactions, some
features otherwise available in MySQL are not supported when using
it. This section provides information about restrictions on and
limitations of replication with GTIDs.
</p>
<p>
<b>
Updates involving nontransactional storage engines.
</b>
When using GTIDs, updates to tables using nontransactional
storage engines such as
<a class="link" href="myisam-storage-engine.html" title="18.2 The MyISAM Storage Engine">
<code class="literal">
MyISAM
</code>
</a>
cannot be made in the same statement or transaction as updates
to tables using transactional storage engines such as
<a class="link" href="innodb-storage-engine.html" title="Chapter 17 The InnoDB Storage Engine">
<code class="literal">
InnoDB
</code>
</a>
.
</p>
<p>
This restriction is due to the fact that updates to tables that
use a nontransactional storage engine mixed with updates to tables
that use a transactional storage engine within the same
transaction can result in multiple GTIDs being assigned to the
same transaction.
</p>
<p>
Such problems can also occur when the source and the replica use
different storage engines for their respective versions of the
same table, where one storage engine is transactional and the
other is not. Also be aware that triggers that are defined to
operate on nontransactional tables can be the cause of these
problems.
</p>
<p>
In any of the cases just mentioned, the one-to-one correspondence
between transactions and GTIDs is broken, with the result that
GTID-based replication cannot function correctly.
</p>
<p>
<b>
CREATE TABLE ... SELECT statements.
</b>
For storage engines which support atomic DDL,
<a class="link" href="create-table-select.html" title="15.1.20.4 CREATE TABLE ... SELECT Statement">
<code class="literal">
CREATE
TABLE ... SELECT
</code>
</a>
is recorded in the binary log as one
transaction. For more information, see
<a class="xref" href="atomic-ddl.html" title="15.1.1 Atomic Data Definition Statement Support">
Section 15.1.1, “Atomic Data Definition Statement Support”
</a>
.
</p>
<p>
<b>
Temporary tables.
</b>
If
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_format">
<code class="literal">
binlog_format
</code>
</a>
is set to
<code class="literal">
STATEMENT
</code>
,
<a class="link" href="create-table.html" title="15.1.20 CREATE TABLE Statement">
<code class="literal">
CREATE TEMPORARY
TABLE
</code>
</a>
and
<a class="link" href="drop-table.html" title="15.1.32 DROP TABLE Statement">
<code class="literal">
DROP TEMPORARY
TABLE
</code>
</a>
statements cannot be used inside transactions,
procedures, functions, and triggers when GTIDs are in use on the
server (that is, when the
<a class="link" href="replication-options-gtids.html#sysvar_enforce_gtid_consistency">
<code class="literal">
enforce_gtid_consistency
</code>
</a>
system
variable is set to
<code class="literal">
ON
</code>
). They can be used
outside these contexts when GTIDs are in use, provided that
<a class="link" href="server-system-variables.html#sysvar_autocommit">
<code class="literal">
autocommit=1
</code>
</a>
is set. When
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_format">
<code class="literal">
binlog_format
</code>
</a>
is set to
<code class="literal">
ROW
</code>
or
<code class="literal">
MIXED
</code>
,
<a class="link" href="create-table.html" title="15.1.20 CREATE TABLE Statement">
<code class="literal">
CREATE TEMPORARY
TABLE
</code>
</a>
and
<a class="link" href="drop-table.html" title="15.1.32 DROP TABLE Statement">
<code class="literal">
DROP TEMPORARY
TABLE
</code>
</a>
statements are allowed inside a transaction,
procedure, function, or trigger when GTIDs are in use. The
statements are not written to the binary log and are therefore
not replicated to replicas. The use of row-based replication
means that the replicas remain in sync without the need to
replicate temporary tables. If the removal of these statements
from a transaction results in an empty transaction, the
transaction is not written to the binary log.
</p>
<p>
<b>
Preventing execution of unsupported statements.
</b>
To prevent execution of statements that would cause GTID-based
replication to fail, all servers must be started with the
<a class="link" href="replication-options-gtids.html#sysvar_enforce_gtid_consistency">
<code class="option">
--enforce-gtid-consistency
</code>
</a>
option
when enabling GTIDs. This causes statements of any of the types
discussed previously in this section to fail with an error.
</p>
<p>
Note that
<a class="link" href="replication-options-gtids.html#sysvar_enforce_gtid_consistency">
<code class="option">
--enforce-gtid-consistency
</code>
</a>
only
takes effect if binary logging takes place for a statement. If
binary logging is disabled on the server, or if statements are not
written to the binary log because they are removed by a filter,
GTID consistency is not checked or enforced for the statements
that are not logged.
</p>
<p>
For information about other required startup options when enabling
GTIDs, see
<a class="xref" href="replication-gtids-howto.html" title="19.1.3.4 Setting Up Replication Using GTIDs">
Section 19.1.3.4, “Setting Up Replication Using GTIDs”
</a>
.
</p>
<p>
<b>
Skipping transactions.
</b>
<a class="link" href="replication-options-replica.html#sysvar_sql_replica_skip_counter">
<code class="literal">
sql_replica_skip_counter
</code>
</a>
is not
available when using GTID-based replication. If you need to skip
transactions, use the value of the source's
<a class="link" href="replication-options-gtids.html#sysvar_gtid_executed">
<code class="literal">
gtid_executed
</code>
</a>
variable instead.
If you have enabled GTID assignment on a replication channel
using the
<code class="literal">
ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS
</code>
option
of the
<a class="link" href="change-replication-source-to.html" title="15.4.2.2 CHANGE REPLICATION SOURCE TO Statement">
<code class="literal">
CHANGE REPLICATION SOURCE
TO
</code>
</a>
statement,
<a class="link" href="replication-options-replica.html#sysvar_sql_replica_skip_counter">
<code class="literal">
sql_replica_skip_counter
</code>
</a>
is
available. For more information, see
<a class="xref" href="replication-administration-skip.html" title="19.1.7.3 Skipping Transactions">
Section 19.1.7.3, “Skipping Transactions”
</a>
.
</p>
<p>
<b>
Ignoring servers.
</b>
<a class="link" href="change-replication-source-to.html#crs-opt-ignore_server_ids">
<code class="literal">
IGNORE_SERVER_IDS
</code>
</a>
cannot be
used with
<a class="link" href="change-replication-source-to.html" title="15.4.2.2 CHANGE REPLICATION SOURCE TO Statement">
<code class="literal">
CHANGE REPLICATION SOURCE
TO
</code>
</a>
when using GTIDs, because transactions that have
already been applied are automatically ignored. Before starting
GTID-based replication, check for and clear all ignored server
ID lists that have previously been set on the servers involved.
The
<a class="link" href="show-replica-status.html" title="15.7.7.35 SHOW REPLICA STATUS Statement">
<code class="literal">
SHOW REPLICA STATUS
</code>
</a>
statement, which can be issued for individual channels, displays
the list of ignored server IDs if there is one. If there is no
list, the
<code class="literal">
Replicate_Ignore_Server_Ids
</code>
field
is blank. If the list of ignored server IDs is not empty, you
can clear it with
<code class="literal">
CHANGE REPLICATION SOURCE TO ...
IGNORE_SERVER_IDS=()
</code>
(in other words, with an empty
list of server IDs to be ignored).
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/partitioning.html | <div id="docs-body">
<div class="chapter">
<div class="titlepage">
<div>
<div>
<h1 class="title">
<a name="partitioning">
</a>
Chapter 26 Partitioning
</h1>
</div>
</div>
</div>
<div class="toc">
<p>
<b>
Table of Contents
</b>
</p>
<dl class="toc">
<dt>
<span class="section">
<a href="partitioning-overview.html">
26.1 Overview of Partitioning in MySQL
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="partitioning-types.html">
26.2 Partitioning Types
</a>
</span>
</dt>
<dd>
<dl>
<dt>
<span class="section">
<a href="partitioning-range.html">
26.2.1 RANGE Partitioning
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="partitioning-list.html">
26.2.2 LIST Partitioning
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="partitioning-columns.html">
26.2.3 COLUMNS Partitioning
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="partitioning-hash.html">
26.2.4 HASH Partitioning
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="partitioning-key.html">
26.2.5 KEY Partitioning
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="partitioning-subpartitions.html">
26.2.6 Subpartitioning
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="partitioning-handling-nulls.html">
26.2.7 How MySQL Partitioning Handles NULL
</a>
</span>
</dt>
</dl>
</dd>
<dt>
<span class="section">
<a href="partitioning-management.html">
26.3 Partition Management
</a>
</span>
</dt>
<dd>
<dl>
<dt>
<span class="section">
<a href="partitioning-management-range-list.html">
26.3.1 Management of RANGE and LIST Partitions
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="partitioning-management-hash-key.html">
26.3.2 Management of HASH and KEY Partitions
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="partitioning-management-exchange.html">
26.3.3 Exchanging Partitions and Subpartitions with Tables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="partitioning-maintenance.html">
26.3.4 Maintenance of Partitions
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="partitioning-info.html">
26.3.5 Obtaining Information About Partitions
</a>
</span>
</dt>
</dl>
</dd>
<dt>
<span class="section">
<a href="partitioning-pruning.html">
26.4 Partition Pruning
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="partitioning-selection.html">
26.5 Partition Selection
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="partitioning-limitations.html">
26.6 Restrictions and Limitations on Partitioning
</a>
</span>
</dt>
<dd>
<dl>
<dt>
<span class="section">
<a href="partitioning-limitations-partitioning-keys-unique-keys.html">
26.6.1 Partitioning Keys, Primary Keys, and Unique Keys
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="partitioning-limitations-storage-engines.html">
26.6.2 Partitioning Limitations Relating to Storage Engines
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="partitioning-limitations-functions.html">
26.6.3 Partitioning Limitations Relating to Functions
</a>
</span>
</dt>
</dl>
</dd>
</dl>
</div>
<a class="indexterm" name="idm46045085018608">
</a>
<a class="indexterm" name="idm46045085017536">
</a>
<a class="indexterm" name="idm46045085016464">
</a>
<a class="indexterm" name="idm46045085014976">
</a>
<a class="indexterm" name="idm46045085013488">
</a>
<p>
This chapter discusses
<span class="firstterm">
user-defined
partitioning
</span>
.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
Table partitioning differs from partitioning as used by window
functions. For information about window functions, see
<a class="xref" href="window-functions.html" title="14.20 Window Functions">
Section 14.20, “Window Functions”
</a>
.
</p>
</div>
<p>
In MySQL 8.4, partitioning support is provided by the
<a class="link" href="innodb-storage-engine.html" title="Chapter 17 The InnoDB Storage Engine">
<code class="literal">
InnoDB
</code>
</a>
and
<a class="link" href="mysql-cluster.html" title="Chapter 25 MySQL NDB Cluster 8.4">
<code class="literal">
NDB
</code>
</a>
storage engines.
</p>
<p>
MySQL 8.4 does not currently support partitioning of
tables using any storage engine other than
<code class="literal">
InnoDB
</code>
or
<code class="literal">
NDB
</code>
, such as
<a class="link" href="myisam-storage-engine.html" title="18.2 The MyISAM Storage Engine">
<code class="literal">
MyISAM
</code>
</a>
. An attempt to create a
partitioned tables using a storage engine that does not supply
native partitioning support fails with
<a class="ulink" href="/doc/mysql-errors/8.4/en/server-error-reference.html#error_er_check_not_implemented" target="_top">
<code class="literal">
ER_CHECK_NOT_IMPLEMENTED
</code>
</a>
.
</p>
<p>
MySQL 8.4 Community binaries provided by Oracle include
partitioning support provided by the
<code class="literal">
InnoDB
</code>
and
<code class="literal">
NDB
</code>
storage engines. For information about
partitioning support offered in MySQL Enterprise Edition binaries, see
<a class="xref" href="mysql-enterprise.html" title="Chapter 32 MySQL Enterprise Edition">
Chapter 32,
<i>
MySQL Enterprise Edition
</i>
</a>
.
</p>
<p>
If you are compiling MySQL 8.4 from source, configuring
the build with
<code class="literal">
InnoDB
</code>
support is sufficient to
produce binaries with partition support for
<code class="literal">
InnoDB
</code>
tables. For more information, see
<a class="xref" href="source-installation.html" title="2.8 Installing MySQL from Source">
Section 2.8, “Installing MySQL from Source”
</a>
.
</p>
<p>
Nothing further needs to be done to enable partitioning support by
<code class="literal">
InnoDB
</code>
(for example, no special entries are
required in the
<code class="filename">
my.cnf
</code>
file).
</p>
<p>
It is not possible to disable partitioning support by the
<code class="literal">
InnoDB
</code>
storage engine.
</p>
<p>
See
<a class="xref" href="partitioning-overview.html" title="26.1 Overview of Partitioning in MySQL">
Section 26.1, “Overview of Partitioning in MySQL”
</a>
, for an introduction to
partitioning and partitioning concepts.
</p>
<p>
Several types of partitioning are supported, as well as
subpartitioning; see
<a class="xref" href="partitioning-types.html" title="26.2 Partitioning Types">
Section 26.2, “Partitioning Types”
</a>
, and
<a class="xref" href="partitioning-subpartitions.html" title="26.2.6 Subpartitioning">
Section 26.2.6, “Subpartitioning”
</a>
.
</p>
<p>
<a class="xref" href="partitioning-management.html" title="26.3 Partition Management">
Section 26.3, “Partition Management”
</a>
, covers methods of adding,
removing, and altering partitions in existing partitioned tables.
</p>
<p>
<a class="xref" href="partitioning-maintenance.html" title="26.3.4 Maintenance of Partitions">
Section 26.3.4, “Maintenance of Partitions”
</a>
, discusses table
maintenance commands for use with partitioned tables.
</p>
<p>
The
<a class="link" href="information-schema-partitions-table.html" title="28.3.21 The INFORMATION_SCHEMA PARTITIONS Table">
<code class="literal">
PARTITIONS
</code>
</a>
table in the
<code class="literal">
INFORMATION_SCHEMA
</code>
database provides information
about partitions and partitioned tables. See
<a class="xref" href="information-schema-partitions-table.html" title="28.3.21 The INFORMATION_SCHEMA PARTITIONS Table">
Section 28.3.21, “The INFORMATION_SCHEMA PARTITIONS Table”
</a>
, for more
information; for some examples of queries against this table, see
<a class="xref" href="partitioning-handling-nulls.html" title="26.2.7 How MySQL Partitioning Handles NULL">
Section 26.2.7, “How MySQL Partitioning Handles NULL”
</a>
.
</p>
<p>
For known issues with partitioning in MySQL 8.4, see
<a class="xref" href="partitioning-limitations.html" title="26.6 Restrictions and Limitations on Partitioning">
Section 26.6, “Restrictions and Limitations on Partitioning”
</a>
.
</p>
<p>
You may also find the following resources to be useful when working
with partitioned tables.
</p>
<a class="indexterm" name="idm46045084982032">
</a>
<p>
<b>
Additional Resources.
</b>
Other sources of information about user-defined partitioning in
MySQL include the following:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="ulink" href="https://forums.mysql.com/list.php?106" target="_blank">
MySQL Partitioning
Forum
</a>
</p>
<p>
This is the official discussion forum for those interested in or
experimenting with MySQL Partitioning technology. It features
announcements and updates from MySQL developers and others. It
is monitored by members of the Partitioning Development and
Documentation Teams.
</p>
</li>
<li class="listitem">
<p>
<a class="ulink" href="http://www.planetmysql.org/" target="_blank">
PlanetMySQL
</a>
</p>
<p>
A MySQL news site featuring MySQL-related blogs, which should be
of interest to anyone using my MySQL. We encourage you to check
here for links to blogs kept by those working with MySQL
Partitioning, or to have your own blog added to those covered.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/sys-sys-config-insert-set-user.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="sys-sys-config-insert-set-user">
</a>
30.4.2.2 The sys_config_insert_set_user Trigger
</h4>
</div>
</div>
</div>
<p>
For rows added to the
<a class="link" href="sys-sys-config.html" title="30.4.2.1 The sys_config Table">
<code class="literal">
sys_config
</code>
</a>
table by
<code class="literal">
INSERT
</code>
statements, the
<a class="link" href="sys-sys-config-insert-set-user.html" title="30.4.2.2 The sys_config_insert_set_user Trigger">
<code class="literal">
sys_config_insert_set_user
</code>
</a>
trigger sets the
<code class="literal">
set_by
</code>
column to the
current user.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-config-file.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="mysql-cluster-config-file">
</a>
25.4.3 NDB Cluster Configuration Files
</h3>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="mysql-cluster-config-example.html">
25.4.3.1 NDB Cluster Configuration: Basic Example
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="mysql-cluster-config-starting.html">
25.4.3.2 Recommended Starting Configuration for NDB Cluster
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="mysql-cluster-connection-strings.html">
25.4.3.3 NDB Cluster Connection Strings
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="mysql-cluster-computer-definition.html">
25.4.3.4 Defining Computers in an NDB Cluster
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="mysql-cluster-mgm-definition.html">
25.4.3.5 Defining an NDB Cluster Management Server
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="mysql-cluster-ndbd-definition.html">
25.4.3.6 Defining NDB Cluster Data Nodes
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="mysql-cluster-api-definition.html">
25.4.3.7 Defining SQL and Other API Nodes in an NDB Cluster
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="mysql-cluster-system-definition.html">
25.4.3.8 Defining the System
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="mysql-cluster-options-variables.html">
25.4.3.9 MySQL Server Options and Variables for NDB Cluster
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="mysql-cluster-tcp-definition.html">
25.4.3.10 NDB Cluster TCP/IP Connections
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="mysql-cluster-tcp-definition-direct.html">
25.4.3.11 NDB Cluster TCP/IP Connections Using Direct Connections
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="mysql-cluster-shm-definition.html">
25.4.3.12 NDB Cluster Shared-Memory Connections
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="mysql-cluster-data-node-memory-management.html">
25.4.3.13 Data Node Memory Management
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="mysql-cluster-config-send-buffers.html">
25.4.3.14 Configuring NDB Cluster Send Buffer Parameters
</a>
</span>
</dt>
</dl>
</div>
<a class="indexterm" name="idm46045120787392">
</a>
<a class="indexterm" name="idm46045120785904">
</a>
<a class="indexterm" name="idm46045120784416">
</a>
<p>
Configuring NDB Cluster requires working with two files:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="filename">
my.cnf
</code>
: Specifies options for all NDB
Cluster executables. This file, with which you should be
familiar with from previous work with MySQL, must be
accessible by each executable running in the cluster.
</p>
</li>
<li class="listitem">
<p>
<code class="filename">
config.ini
</code>
: This file, sometimes known as
the
<span class="firstterm">
global configuration
file
</span>
, is read only by the NDB Cluster management
server, which then distributes the information contained
therein to all processes participating in the cluster.
<code class="filename">
config.ini
</code>
contains a description of each
node involved in the cluster. This includes configuration
parameters for data nodes and configuration parameters for
connections between all nodes in the cluster. For a quick
reference to the sections that can appear in this file, and
what sorts of configuration parameters may be placed in each
section, see
<a class="link" href="mysql-cluster-config-example.html#mysql-cluster-config-ini-sections" title="Sections of the config.ini File">
Sections of
the
<code class="filename">
config.ini
</code>
File
</a>
.
</p>
</li>
</ul>
</div>
<p>
<b>
Caching of configuration data.
</b>
<code class="literal">
NDB
</code>
uses
<span class="firstterm">
stateful
configuration
</span>
. Rather than reading the global
configuration file every time the management server is
restarted, the management server caches the configuration the
first time it is started, and thereafter, the global
configuration file is read only when one of the following
conditions is true:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<b>
The management server is started using the --initial option.
</b>
When
<a class="link" href="mysql-cluster-programs-ndb-mgmd.html#option_ndb_mgmd_initial">
<code class="option">
--initial
</code>
</a>
is used, the
global configuration file is re-read, any existing cache
files are deleted, and the management server creates a new
configuration cache.
</p>
</li>
<li class="listitem">
<p>
<b>
The management server is started using the --reload option.
</b>
The
<a class="link" href="mysql-cluster-programs-ndb-mgmd.html#option_ndb_mgmd_reload">
<code class="option">
--reload
</code>
</a>
option causes
the management server to compare its cache with the global
configuration file. If they differ, the management server
creates a new configuration cache; any existing
configuration cache is preserved, but not used. If the
management server's cache and the global configuration
file contain the same configuration data, then the existing
cache is used, and no new cache is created.
</p>
</li>
<li class="listitem">
<p>
<b>
The management server is started using --config-cache=FALSE.
</b>
This disables
<a class="link" href="mysql-cluster-programs-ndb-mgmd.html#option_ndb_mgmd_config-cache">
<code class="option">
--config-cache
</code>
</a>
(enabled by
default), and can be used to force the management server to
bypass configuration caching altogether. In this case, the
management server ignores any configuration files that may
be present, always reading its configuration data from the
<code class="filename">
config.ini
</code>
file instead.
</p>
</li>
<li class="listitem">
<p>
<b>
No configuration cache is found.
</b>
In this case, the management server reads the global
configuration file and creates a cache containing the same
configuration data as found in the file.
</p>
</li>
</ul>
</div>
<p>
<b>
Configuration cache files.
</b>
The management server by default creates configuration cache
files in a directory named
<code class="filename">
mysql-cluster
</code>
in
the MySQL installation directory. (If you build NDB Cluster from
source on a Unix system, the default location is
<code class="filename">
/usr/local/mysql-cluster
</code>
.) This can be
overridden at runtime by starting the management server with the
<a class="link" href="mysql-cluster-programs-ndb-mgmd.html#option_ndb_mgmd_configdir">
<code class="option">
--configdir
</code>
</a>
option.
Configuration cache files are binary files named according to
the pattern
<code class="filename">
ndb_
<em class="replaceable">
<code>
node_id
</code>
</em>
_config.bin.
<em class="replaceable">
<code>
seq_id
</code>
</em>
</code>
,
where
<em class="replaceable">
<code>
node_id
</code>
</em>
is the management
server's node ID in the cluster, and
<em class="replaceable">
<code>
seq_id
</code>
</em>
is a cache identifier. Cache
files are numbered sequentially using
<em class="replaceable">
<code>
seq_id
</code>
</em>
, in the order in which they
are created. The management server uses the latest cache file as
determined by the
<em class="replaceable">
<code>
seq_id
</code>
</em>
.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
It is possible to roll back to a previous configuration by
deleting later configuration cache files, or by renaming an
earlier cache file so that it has a higher
<em class="replaceable">
<code>
seq_id
</code>
</em>
. However, since configuration
cache files are written in a binary format, you should not
attempt to edit their contents by hand.
</p>
</div>
<p>
For more information about the
<a class="link" href="mysql-cluster-programs-ndb-mgmd.html#option_ndb_mgmd_configdir">
<code class="option">
--configdir
</code>
</a>
,
<a class="link" href="mysql-cluster-programs-ndb-mgmd.html#option_ndb_mgmd_config-cache">
<code class="option">
--config-cache
</code>
</a>
,
<a class="link" href="mysql-cluster-programs-ndb-mgmd.html#option_ndb_mgmd_initial">
<code class="option">
--initial
</code>
</a>
, and
<a class="link" href="mysql-cluster-programs-ndb-mgmd.html#option_ndb_mgmd_reload">
<code class="option">
--reload
</code>
</a>
options for the NDB
Cluster management server, see
<a class="xref" href="mysql-cluster-programs-ndb-mgmd.html" title="25.5.4 ndb_mgmd — The NDB Cluster Management Server Daemon">
Section 25.5.4, “ndb_mgmd — The NDB Cluster Management Server Daemon”
</a>
.
</p>
<p>
We are continuously making improvements in NDB Cluster
configuration and attempting to simplify this process. Although we
strive to maintain backward compatibility, there may be times when
introduce an incompatible change. In such cases we try to let NDB
Cluster users know in advance if a change is not backward
compatible. If you find such a change and we have not documented
it, please report it in the MySQL bugs database using the
instructions given in
<a class="xref" href="bug-reports.html" title="1.6 How to Report Bugs or Problems">
Section 1.6, “How to Report Bugs or Problems”
</a>
.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/telemetry-metrics-configuration.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="telemetry-metrics-configuration">
</a>
35.4.1 Configuring Metrics Telemetry
</h3>
</div>
</div>
</div>
<p>
</p>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="telemetry-metrics-configuration-server">
</a>
Server Configuration
</h4>
</div>
</div>
</div>
<p>
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a name="sysvar_telemetry.otel_exporter_otlp_metrics_protocol">
</a>
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_protocol">
<code class="literal">
telemetry.otel_exporter_otlp_metrics_protocol
</code>
</a>
</p>
<a class="indexterm" name="idm46045058852816">
</a>
<a class="indexterm" name="idm46045058851696">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for telemetry.otel_exporter_otlp_metrics_protocol">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_protocol">
telemetry.otel_exporter_otlp_metrics_protocol
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Enumeration
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
http/protobuf
</code>
</td>
</tr>
<tr>
<th>
Valid Values
</th>
<td>
<p class="valid-value">
<code class="literal">
http/protobuf
</code>
</p>
<p class="valid-value">
<code class="literal">
http/json
</code>
</p>
</td>
</tr>
</tbody>
</table>
</div>
<p>
The OLTP transport protocol.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
MySQL does not support the
<code class="literal">
gprc
</code>
protocol.
</p>
</div>
</li>
<li class="listitem">
<p>
<a name="sysvar_telemetry.otel_exporter_otlp_metrics_endpoint">
</a>
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_endpoint">
<code class="literal">
telemetry.otel_exporter_otlp_metrics_endpoint
</code>
</a>
</p>
<a class="indexterm" name="idm46045058824016">
</a>
<a class="indexterm" name="idm46045058822896">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for telemetry.otel_exporter_otlp_metrics_endpoint">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_endpoint">
telemetry.otel_exporter_otlp_metrics_endpoint
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
http://localhost:4318/v1/metrics
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Endpoint metric signals are sent to.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_telemetry.otel_exporter_otlp_metrics_certificates">
</a>
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_certificates">
<code class="literal">
telemetry.otel_exporter_otlp_metrics_certificates
</code>
</a>
</p>
<a class="indexterm" name="idm46045058800384">
</a>
<a class="indexterm" name="idm46045058799344">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for telemetry.otel_exporter_otlp_metrics_certificates">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_certificates">
telemetry.otel_exporter_otlp_metrics_certificates
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
The trusted certificate to use when verifying a server's
TLS credentials.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_telemetry.otel_exporter_otlp_metrics_client_key">
</a>
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_client_key">
<code class="literal">
telemetry.otel_exporter_otlp_metrics_client_key
</code>
</a>
</p>
<a class="indexterm" name="idm46045058776896">
</a>
<a class="indexterm" name="idm46045058775856">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for telemetry.otel_exporter_otlp_metrics_client_key">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_client_key">
telemetry.otel_exporter_otlp_metrics_client_key
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Client's private key in PEM format.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_telemetry.otel_exporter_otlp_metrics_client_certificates">
</a>
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_client_certificates">
<code class="literal">
telemetry.otel_exporter_otlp_metrics_client_certificates
</code>
</a>
</p>
<a class="indexterm" name="idm46045058753488">
</a>
<a class="indexterm" name="idm46045058752352">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for telemetry.otel_exporter_otlp_metrics_client_certificates">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_client_certificates">
telemetry.otel_exporter_otlp_metrics_client_certificates
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Client certificate/chain trust for clients private key in
PEM format.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_telemetry.otel_exporter_otlp_metrics_min_tls">
</a>
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_min_tls">
<code class="literal">
telemetry.otel_exporter_otlp_metrics_min_tls
</code>
</a>
</p>
<a class="indexterm" name="idm46045058729952">
</a>
<a class="indexterm" name="idm46045058728832">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for telemetry.otel_exporter_otlp_metrics_min_tls">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_min_tls">
telemetry.otel_exporter_otlp_metrics_min_tls
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Enumeration
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
<tr>
<th>
Valid Values
</th>
<td>
<p class="valid-value">
<code class="literal">
[none]
</code>
</p>
<p class="valid-value">
<code class="literal">
1.2
</code>
</p>
<p class="valid-value">
<code class="literal">
1.3
</code>
</p>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Minimum TLS version to use for metrics.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_telemetry.otel_exporter_otlp_metrics_max_tls">
</a>
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_max_tls">
<code class="literal">
telemetry.otel_exporter_otlp_metrics_max_tls
</code>
</a>
</p>
<a class="indexterm" name="idm46045058701728">
</a>
<a class="indexterm" name="idm46045058700608">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for telemetry.otel_exporter_otlp_metrics_max_tls">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_max_tls">
telemetry.otel_exporter_otlp_metrics_max_tls
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Enumeration
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
<tr>
<th>
Valid Values
</th>
<td>
<p class="valid-value">
<code class="literal">
[none]
</code>
</p>
<p class="valid-value">
<code class="literal">
1.2
</code>
</p>
<p class="valid-value">
<code class="literal">
1.3
</code>
</p>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Maximum TLS version to use for metrics.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_telemetry.otel_exporter_otlp_metrics_cipher">
</a>
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_cipher">
<code class="literal">
telemetry.otel_exporter_otlp_metrics_cipher
</code>
</a>
</p>
<a class="indexterm" name="idm46045058673552">
</a>
<a class="indexterm" name="idm46045058672432">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for telemetry.otel_exporter_otlp_metrics_cipher">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_cipher">
telemetry.otel_exporter_otlp_metrics_cipher
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
TLS cipher to use for metrics (TLS 1.2).
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_telemetry.otel_exporter_otlp_metrics_cipher_suite">
</a>
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_cipher_suite">
<code class="literal">
telemetry.otel_exporter_otlp_metrics_cipher_suite
</code>
</a>
</p>
<a class="indexterm" name="idm46045058650000">
</a>
<a class="indexterm" name="idm46045058648960">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for telemetry.otel_exporter_otlp_metrics_cipher_suite">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_cipher_suite">
telemetry.otel_exporter_otlp_metrics_cipher_suite
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
TLS cipher to use for metrics (TLS 1.3).
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_telemetry.otel_exporter_otlp_metrics_headers">
</a>
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_headers">
<code class="literal">
telemetry.otel_exporter_otlp_metrics_headers
</code>
</a>
</p>
<a class="indexterm" name="idm46045058626576">
</a>
<a class="indexterm" name="idm46045058625456">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for telemetry.otel_exporter_otlp_metrics_headers">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_headers">
telemetry.otel_exporter_otlp_metrics_headers
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Key-value pairs to be used as headers associated with HTTP
requests.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_telemetry.otel_exporter_otlp_metrics_compression">
</a>
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_compression">
<code class="literal">
telemetry.otel_exporter_otlp_metrics_compression
</code>
</a>
</p>
<a class="indexterm" name="idm46045058603120">
</a>
<a class="indexterm" name="idm46045058602000">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for telemetry.otel_exporter_otlp_metrics_compression">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_compression">
telemetry.otel_exporter_otlp_metrics_compression
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
none (no compression)
</code>
</td>
</tr>
<tr>
<th>
Valid Values
</th>
<td>
<p class="valid-value">
<code class="literal">
none (no compression)
</code>
</p>
<p class="valid-value">
<code class="literal">
gzip
</code>
</p>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Compression used by exporter
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_telemetry.otel_exporter_otlp_metrics_timeout">
</a>
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_timeout">
<code class="literal">
telemetry.otel_exporter_otlp_metrics_timeout
</code>
</a>
</p>
<a class="indexterm" name="idm46045058575840">
</a>
<a class="indexterm" name="idm46045058574720">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for telemetry.otel_exporter_otlp_metrics_timeout">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.otel_exporter_otlp_metrics_timeout">
telemetry.otel_exporter_otlp_metrics_timeout
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
10000
</code>
</td>
</tr>
<tr>
<th>
Unit
</th>
<td>
milliseconds
</td>
</tr>
</tbody>
</table>
</div>
<p>
Time in milliseconds the OLTP exporter waits for each
batch export.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_telemetry.metrics_reader_frequency_1">
</a>
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.metrics_reader_frequency_1">
<code class="literal">
telemetry.metrics_reader_frequency_1
</code>
</a>
</p>
<a class="indexterm" name="idm46045058550288">
</a>
<a class="indexterm" name="idm46045058549248">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for telemetry.metrics_reader_frequency_1">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.metrics_reader_frequency_1">
telemetry.metrics_reader_frequency_1
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
10
</code>
</td>
</tr>
<tr>
<th>
Unit
</th>
<td>
seconds
</td>
</tr>
</tbody>
</table>
</div>
<p>
Mandatory. Defines the interval in seconds (f1) between
meter evaluations for meters with a frequency less than or
equal to the interval, f1. For example:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa59056416"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">from</span> performance_schema<span class="token punctuation">.</span>setup_meters <span class="token keyword">WHERE</span> FREQUENCY <span class="token operator"><=</span> telemetry<span class="token punctuation">.</span>metrics_reader_frequency_1</code></pre>
</div>
</li>
<li class="listitem">
<p>
<a name="sysvar_telemetry.metrics_reader_frequency_2">
</a>
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.metrics_reader_frequency_2">
<code class="literal">
telemetry.metrics_reader_frequency_2
</code>
</a>
</p>
<a class="indexterm" name="idm46045058523760">
</a>
<a class="indexterm" name="idm46045058522720">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for telemetry.metrics_reader_frequency_2">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.metrics_reader_frequency_2">
telemetry.metrics_reader_frequency_2
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
10
</code>
</td>
</tr>
<tr>
<th>
Unit
</th>
<td>
seconds
</td>
</tr>
</tbody>
</table>
</div>
<p>
Optional. Defines the interval in seconds (f2) between
meter evaluations for meters with a frequency greater than
the interval, f1. For example, if f1 and f2 are defined:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa59303373"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">from</span> performance_schema<span class="token punctuation">.</span>setup_meters <span class="token keyword">WHERE</span> FREQUENCY <span class="token operator"><=</span> telemetry<span class="token punctuation">.</span>metrics_reader_frequency_1</code></pre>
</div>
<p>
and, every f2 seconds:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa50957424"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">from</span> performance_schema<span class="token punctuation">.</span>setup_meters
<span class="token keyword">WHERE</span> FREQUENCY <span class="token operator">></span> telemetry<span class="token punctuation">.</span>metrics_reader_frequency_1
<span class="token operator">AND</span> FREQUENCY <span class="token operator"><=</span> metrics_reader_frequency_2<span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
<a name="sysvar_telemetry.metrics_reader_frequency_3">
</a>
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.metrics_reader_frequency_3">
<code class="literal">
telemetry.metrics_reader_frequency_3
</code>
</a>
</p>
<a class="indexterm" name="idm46045058495664">
</a>
<a class="indexterm" name="idm46045058494624">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for telemetry.metrics_reader_frequency_3">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="telemetry-metrics-configuration.html#sysvar_telemetry.metrics_reader_frequency_3">
telemetry.metrics_reader_frequency_3
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
10
</code>
</td>
</tr>
<tr>
<th>
Unit
</th>
<td>
seconds
</td>
</tr>
</tbody>
</table>
</div>
<p>
Optional. Defines the interval in seconds (f3) between
meter evaluations for meters with a frequency greater than
the interval, f2. For example, if f1, f2, and f3 are
defined:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa55773862"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">from</span> performance_schema<span class="token punctuation">.</span>setup_meters <span class="token keyword">WHERE</span> FREQUENCY <span class="token operator"><=</span> telemetry<span class="token punctuation">.</span>metrics_reader_frequency_1</code></pre>
</div>
<p>
and, every f2 seconds:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa76965163"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">from</span> performance_schema<span class="token punctuation">.</span>setup_meters
<span class="token keyword">WHERE</span> FREQUENCY <span class="token operator">></span> telemetry<span class="token punctuation">.</span>metrics_reader_frequency_1
<span class="token operator">AND</span> FREQUENCY <span class="token operator"><=</span> metrics_reader_frequency_2<span class="token punctuation">;</span></code></pre>
</div>
<p>
and, every f3 seconds:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa65734409"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">from</span> performance_schema<span class="token punctuation">.</span>setup_meters <span class="token keyword">WHERE</span> FREQUENCY <span class="token operator">></span> telemetry<span class="token punctuation">.</span>metrics_reader_frequency_2<span class="token punctuation">;</span></code></pre>
</div>
</li>
</ul>
</div>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/sys-ps-setup-enable-consumer.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="sys-ps-setup-enable-consumer">
</a>
30.4.4.9 The ps_setup_enable_consumer() Procedure
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045061478352">
</a>
<a class="indexterm" name="idm46045061476896">
</a>
<p>
Enables Performance Schema consumers with names that contain
the argument. Produces a result set indicating how many
consumers were enabled. Already enabled consumers do not
count.
</p>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="sys-ps-setup-enable-consumer-parameters">
</a>
Parameters
</h5>
</div>
</div>
</div>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
consumer VARCHAR(128)
</code>
: The value used
to match consumer names, which are identified by using
<code class="literal">
%consumer%
</code>
as an operand for a
<a class="link" href="string-comparison-functions.html#operator_like">
<code class="literal">
LIKE
</code>
</a>
pattern match.
</p>
<p>
A value of
<code class="literal">
''
</code>
matches all consumers.
</p>
</li>
</ul>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="sys-ps-setup-enable-consumer-example">
</a>
Example
</h5>
</div>
</div>
</div>
<p>
Enable all statement consumers:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa51932575"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">CALL</span> sys<span class="token punctuation">.</span>ps_setup_enable_consumer<span class="token punctuation">(</span><span class="token string">'statement'</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> summary <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> Enabled 4 consumers <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-mgm-client-commands.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="mysql-cluster-mgm-client-commands">
</a>
25.6.1 Commands in the NDB Cluster Management Client
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045094630320">
</a>
<a class="indexterm" name="idm46045094628832">
</a>
<a class="indexterm" name="idm46045094627344">
</a>
<p>
In addition to the central configuration file, a cluster may also
be controlled through a command-line interface available through
the management client
<a class="link" href="mysql-cluster-programs-ndb-mgm.html" title="25.5.5 ndb_mgm — The NDB Cluster Management Client">
<span class="command">
<strong>
ndb_mgm
</strong>
</span>
</a>
. This is the
primary administrative interface to a running cluster.
</p>
<p>
Commands for the event logs are given in
<a class="xref" href="mysql-cluster-event-reports.html" title="25.6.3 Event Reports Generated in NDB Cluster">
Section 25.6.3, “Event Reports Generated in NDB Cluster”
</a>
; commands for
creating backups and restoring from them are provided in
<a class="xref" href="mysql-cluster-backup.html" title="25.6.8 Online Backup of NDB Cluster">
Section 25.6.8, “Online Backup of NDB Cluster”
</a>
.
</p>
<p>
<b>
Using ndb_mgm with MySQL Cluster Manager.
</b>
<a class="indexterm" name="idm46045094621152">
</a>
<a class="indexterm" name="idm46045094619648">
</a>
MySQL Cluster Manager handles starting and stopping processes and tracks their
states internally, so it is not necessary to use
<a class="link" href="mysql-cluster-programs-ndb-mgm.html" title="25.5.5 ndb_mgm — The NDB Cluster Management Client">
<span class="command">
<strong>
ndb_mgm
</strong>
</span>
</a>
for these tasks for an NDB Cluster
that is under MySQL Cluster Manager control. It is recommended
<span class="emphasis">
<em>
not
</em>
</span>
to use the
<a class="link" href="mysql-cluster-programs-ndb-mgm.html" title="25.5.5 ndb_mgm — The NDB Cluster Management Client">
<span class="command">
<strong>
ndb_mgm
</strong>
</span>
</a>
command-line client that comes with the NDB Cluster distribution
to perform operations that involve starting or stopping nodes.
These include but are not limited to the
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-start">
<code class="literal">
START
</code>
</a>
,
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-stop">
<code class="literal">
STOP
</code>
</a>
,
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-restart">
<code class="literal">
RESTART
</code>
</a>
, and
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-shutdown">
<code class="literal">
SHUTDOWN
</code>
</a>
commands. For more
information, see
<a class="ulink" href="/doc/mysql-cluster-manager/8.4/en/mcm-process-commands.html" target="_top">
MySQL Cluster Manager Process Commands
</a>
.
</p>
<p>
The management client has the following basic commands. In the
listing that follows,
<em class="replaceable">
<code>
node_id
</code>
</em>
denotes
either a data node ID or the keyword
<code class="literal">
ALL
</code>
, which
indicates that the command should be applied to all of the
cluster's data nodes.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a name="ndbclient-connect">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-connect">
<code class="literal">
CONNECT
<em class="replaceable">
<code>
connection-string
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045094603824">
</a>
<a class="indexterm" name="idm46045094602336">
</a>
<p>
Connects to the management server indicated by the connection
string. If the client is already connected to this server, the
client reconnects.
</p>
</li>
<li class="listitem">
<p>
<a name="ndbclient-create-nodegroup">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-create-nodegroup">
<code class="literal">
CREATE NODEGROUP
<em class="replaceable">
<code>
nodeid
</code>
</em>
[,
<em class="replaceable">
<code>
nodeid
</code>
</em>
, ...]
</code>
</a>
</p>
<a class="indexterm" name="idm46045094597184">
</a>
<a class="indexterm" name="idm46045094595680">
</a>
<p>
Creates a new NDB Cluster node group and causes data nodes to
join it.
</p>
<p>
This command is used after adding new data nodes online to an
NDB Cluster, and causes them to join a new node group and thus
to begin participating fully in the cluster. The command takes
as its sole parameter a comma-separated list of node
IDs—these are the IDs of the nodes just added and
started, and that are to join the new node group. The list
must contain no duplicate IDs; the presence of any duplicates
causes the command to return an error. The number of nodes in
the list must be the same as the number of nodes in each node
group that is already part of the cluster (each NDB Cluster
node group must have the same number of nodes). In other
words, if the NDB Cluster consists of 2 node groups having 2
data nodes each, then the new node group must also have 2 data
nodes.
</p>
<p>
The node group ID of the new node group created by this
command is determined automatically, and always the next
highest unused node group ID in the cluster; it is not
possible to set it manually.
</p>
<p>
For more information, see
<a class="xref" href="mysql-cluster-online-add-node.html" title="25.6.7 Adding NDB Cluster Data Nodes Online">
Section 25.6.7, “Adding NDB Cluster Data Nodes Online”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="ndbclient-drop-nodegroup">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-drop-nodegroup">
<code class="literal">
DROP NODEGROUP
<em class="replaceable">
<code>
nodegroup_id
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045094587840">
</a>
<a class="indexterm" name="idm46045094586352">
</a>
<p>
Drops the NDB Cluster node group with the given
<em class="replaceable">
<code>
nodegroup_id
</code>
</em>
.
</p>
<p>
This command can be used to drop a node group from an NDB
Cluster.
<code class="literal">
DROP NODEGROUP
</code>
takes as its sole
argument the node group ID of the node group to be dropped.
</p>
<p>
<code class="literal">
DROP NODEGROUP
</code>
acts only to remove the data
nodes in the effected node group from that node group. It does
not stop data nodes, assign them to a different node group, or
remove them from the cluster's configuration. A data node
that does not belong to a node group is indicated in the
output of the management client
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-show">
<code class="literal">
SHOW
</code>
</a>
command with
<code class="literal">
no nodegroup
</code>
in place of the node group ID,
like this (indicated using bold text):
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-simple"><div class="docs-select-all right" id="sa39078685"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-simple">id<span class="token operator">=</span>3 @10<span class="token punctuation">.</span>100<span class="token punctuation">.</span>2<span class="token punctuation">.</span>67 <span class="token punctuation">(</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0<span class="token operator">-</span>ndb<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0<span class="token punctuation">,</span> no nodegroup<span class="token punctuation">)</span></code></pre>
</div>
<p>
<code class="literal">
DROP NODEGROUP
</code>
works only when all data
nodes in the node group to be dropped are completely empty of
any table data and table definitions. Since there is currently
no way using
<a class="link" href="mysql-cluster-programs-ndb-mgm.html" title="25.5.5 ndb_mgm — The NDB Cluster Management Client">
<span class="command">
<strong>
ndb_mgm
</strong>
</span>
</a>
or the
<a class="link" href="mysql.html" title="6.5.1 mysql — The MySQL Command-Line Client">
<span class="command">
<strong>
mysql
</strong>
</span>
</a>
client to remove all data from a
specific data node or node group, this means that the command
succeeds only in the two following cases:
</p>
<div class="orderedlist">
<ol class="orderedlist" type="1">
<li class="listitem">
<p>
After issuing
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-create-nodegroup">
<code class="literal">
CREATE
NODEGROUP
</code>
</a>
in the
<a class="link" href="mysql-cluster-programs-ndb-mgm.html" title="25.5.5 ndb_mgm — The NDB Cluster Management Client">
<span class="command">
<strong>
ndb_mgm
</strong>
</span>
</a>
client, but before issuing any
<a class="link" href="alter-table.html" title="15.1.9 ALTER TABLE Statement">
<code class="literal">
ALTER TABLE
... REORGANIZE PARTITION
</code>
</a>
statements in the
<a class="link" href="mysql.html" title="6.5.1 mysql — The MySQL Command-Line Client">
<span class="command">
<strong>
mysql
</strong>
</span>
</a>
client.
</p>
</li>
<li class="listitem">
<p>
After dropping all
<a class="link" href="mysql-cluster.html" title="Chapter 25 MySQL NDB Cluster 8.4">
<code class="literal">
NDBCLUSTER
</code>
</a>
tables using
<a class="link" href="drop-table.html" title="15.1.32 DROP TABLE Statement">
<code class="literal">
DROP TABLE
</code>
</a>
.
</p>
<p>
<a class="link" href="truncate-table.html" title="15.1.37 TRUNCATE TABLE Statement">
<code class="literal">
TRUNCATE TABLE
</code>
</a>
does not
work for this purpose because this removes only the table
data; the data nodes continue to store an
<a class="link" href="mysql-cluster.html" title="Chapter 25 MySQL NDB Cluster 8.4">
<code class="literal">
NDBCLUSTER
</code>
</a>
table's
definition until a
<a class="link" href="drop-table.html" title="15.1.32 DROP TABLE Statement">
<code class="literal">
DROP
TABLE
</code>
</a>
statement is issued that causes the table
metadata to be dropped.
</p>
</li>
</ol>
</div>
<p>
For more information about
<code class="literal">
DROP NODEGROUP
</code>
,
see
<a class="xref" href="mysql-cluster-online-add-node.html" title="25.6.7 Adding NDB Cluster Data Nodes Online">
Section 25.6.7, “Adding NDB Cluster Data Nodes Online”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="ndbclient-enter-single-user-mode">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-enter-single-user-mode">
<code class="literal">
ENTER SINGLE USER MODE
<em class="replaceable">
<code>
node_id
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045094554832">
</a>
<a class="indexterm" name="idm46045094553344">
</a>
<a class="indexterm" name="idm46045094552256">
</a>
<a class="indexterm" name="idm46045094550752">
</a>
<p>
Enters single user mode, whereby only the MySQL server
identified by the node ID
<em class="replaceable">
<code>
node_id
</code>
</em>
is permitted to access the database.
</p>
<p>
The
<a class="link" href="mysql-cluster-programs-ndb-mgm.html" title="25.5.5 ndb_mgm — The NDB Cluster Management Client">
<span class="command">
<strong>
ndb_mgm
</strong>
</span>
</a>
client provides a clear
acknowledgement that this command has been issued and has
taken effect, as shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-ndbmgm"><div class="docs-select-all right" id="sa15491757"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-ndbmgm"><span class="token prompt">ndb_mgm></span> <span class="token keyword">ENTER SINGLE USER MODE</span> 100
Single user mode entered
Access is granted for API node 100 only<span class="token punctuation">.</span></code></pre>
</div>
<p>
In addition, the API or SQL node having exclusive access when
in single user mode is indicated in the output of the
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-show">
<code class="literal">
SHOW
</code>
</a>
command, like this:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-ndbmgm"><div class="docs-select-all right" id="sa79733307"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-ndbmgm"><span class="token prompt">ndb_mgm></span> <span class="token keyword">SHOW</span>
Cluster Configuration
<span class="token operator">--</span><span class="token operator">--</span><span class="token operator">--</span><span class="token operator">--</span><span class="token operator">--</span><span class="token operator">--</span><span class="token operator">--</span><span class="token operator">--</span><span class="token operator">--</span><span class="token operator">--</span><span class="token operator">-</span>
<span class="token selector">[ndbd(NDB)]</span> 2 node<span class="token punctuation">(</span>s<span class="token punctuation">)</span>
id<span class="token operator">=</span>5 @127<span class="token punctuation">.</span>0<span class="token punctuation">.</span>0<span class="token punctuation">.</span>1 <span class="token punctuation">(</span>mysql<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0 ndb<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0<span class="token punctuation">,</span> single user mode<span class="token punctuation">,</span> Nodegroup<span class="token operator">:</span> 0<span class="token punctuation">,</span> <span class="token operator">*</span><span class="token punctuation">)</span>
id<span class="token operator">=</span>6 @127<span class="token punctuation">.</span>0<span class="token punctuation">.</span>0<span class="token punctuation">.</span>1 <span class="token punctuation">(</span>mysql<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0 ndb<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0<span class="token punctuation">,</span> single user mode<span class="token punctuation">,</span> Nodegroup<span class="token operator">:</span> 0<span class="token punctuation">)</span>
<span class="token selector">[ndb_mgmd(MGM)]</span> 1 node<span class="token punctuation">(</span>s<span class="token punctuation">)</span>
id<span class="token operator">=</span>50 @127<span class="token punctuation">.</span>0<span class="token punctuation">.</span>0<span class="token punctuation">.</span>1 <span class="token punctuation">(</span>mysql<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0 ndb<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0<span class="token punctuation">)</span>
<span class="token selector">[mysqld(API)]</span> 2 node<span class="token punctuation">(</span>s<span class="token punctuation">)</span>
id<span class="token operator">=</span>100 @127<span class="token punctuation">.</span>0<span class="token punctuation">.</span>0<span class="token punctuation">.</span>1 <span class="token punctuation">(</span>mysql<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0 ndb<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0<span class="token punctuation">,</span> allowed single user<span class="token punctuation">)</span>
id<span class="token operator">=</span>101 <span class="token punctuation">(</span>not connected<span class="token punctuation">,</span> accepting connect from any host<span class="token punctuation">)</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
<a name="ndbclient-exit-single-user-mode">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-exit-single-user-mode">
<code class="literal">
EXIT SINGLE USER MODE
</code>
</a>
</p>
<a class="indexterm" name="idm46045094539184">
</a>
<a class="indexterm" name="idm46045094537728">
</a>
<p>
Exits single user mode, enabling all SQL nodes (that is, all
running
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
processes) to access the
database.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
It is possible to use
<code class="literal">
EXIT SINGLE USER
MODE
</code>
even when not in single user mode, although
the command has no effect in this case.
</p>
</div>
</li>
<li class="listitem">
<p>
<a name="ndbclient-help">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-help">
<code class="literal">
HELP
</code>
</a>
</p>
<a class="indexterm" name="idm46045094530704">
</a>
<a class="indexterm" name="idm46045094529216">
</a>
<p>
Displays information on all available commands.
</p>
</li>
<li class="listitem">
<p>
<a name="ndbclient-nodelog-debug">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-nodelog-debug">
<code class="literal">
<em class="replaceable">
<code>
node_id
</code>
</em>
NODELOG DEBUG {ON|OFF}
</code>
</a>
</p>
<a class="indexterm" name="idm46045094524960">
</a>
<a class="indexterm" name="idm46045094523472">
</a>
<p>
Toggles debug logging in the node log, as though the effected
data node or nodes had been started with the
<a class="link" href="mysql-cluster-programs-ndbd.html#option_ndbd_verbose">
<code class="option">
--verbose
</code>
</a>
option.
<code class="literal">
NODELOG DEBUG ON
</code>
starts debug logging;
<code class="literal">
NODELOG DEBUG OFF
</code>
switches debug logging
off.
</p>
</li>
<li class="listitem">
<p>
<a name="ndbclient-prompt">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-prompt">
<code class="literal">
PROMPT
[
<em class="replaceable">
<code>
prompt
</code>
</em>
]
</code>
</a>
</p>
<a class="indexterm" name="idm46045094516464">
</a>
<a class="indexterm" name="idm46045094514976">
</a>
<p>
Changes the prompt shown by
<a class="link" href="mysql-cluster-programs-ndb-mgm.html" title="25.5.5 ndb_mgm — The NDB Cluster Management Client">
<span class="command">
<strong>
ndb_mgm
</strong>
</span>
</a>
to the
string literal
<em class="replaceable">
<code>
prompt
</code>
</em>
.
</p>
<p>
<em class="replaceable">
<code>
prompt
</code>
</em>
should not be quoted (unless
you want the prompt to include the quotation marks). Unlike
the case with the
<a class="link" href="mysql.html" title="6.5.1 mysql — The MySQL Command-Line Client">
<span class="command">
<strong>
mysql
</strong>
</span>
</a>
client, special
character sequences and escapes are not recognized. If called
without an argument, the command resets the prompt to the
default value (
<code class="literal">
ndb_mgm>
</code>
).
</p>
<p>
Some examples are shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-ndbmgm"><div class="docs-select-all right" id="sa36712346"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-ndbmgm"><span class="token prompt">ndb_mgm></span> <span class="token keyword">PROMPT</span> mgm#1<span class="token operator">:</span>
mgm#1<span class="token operator">:</span> <span class="token keyword">SHOW</span>
Cluster Configuration
<span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span>
mgm#1<span class="token operator">:</span> <span class="token keyword">PROMPT</span> mymgm <span class="token operator">></span>
mymgm <span class="token operator">></span> <span class="token keyword">PROMPT</span> 'mymgm<span class="token operator">:</span>'
'mymgm<span class="token operator">:</span>' <span class="token keyword">PROMPT</span> mymgm<span class="token operator">:</span>
mymgm<span class="token operator">:</span> <span class="token keyword">PROMPT</span>
<span class="token prompt">ndb_mgm></span> <span class="token keyword">EXIT</span>
$<span class="token operator">></span></code></pre>
</div>
<p>
Note that leading spaces and spaces within the
<em class="replaceable">
<code>
prompt
</code>
</em>
string are not trimmed.
Trailing spaces are removed.
</p>
</li>
<li class="listitem">
<p>
<a name="ndbclient-quit">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-quit">
<code class="literal">
QUIT
</code>
</a>
,
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-quit">
<code class="literal">
EXIT
</code>
</a>
</p>
<a class="indexterm" name="idm46045094497536">
</a>
<a class="indexterm" name="idm46045094496048">
</a>
<a class="indexterm" name="idm46045094494960">
</a>
<a class="indexterm" name="idm46045094493472">
</a>
<p>
Terminates the management client.
</p>
<p>
This command does not affect any nodes connected to the
cluster.
</p>
</li>
<li class="listitem">
<p>
<a name="ndbclient-report">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-report">
<code class="literal">
<em class="replaceable">
<code>
node_id
</code>
</em>
REPORT
<em class="replaceable">
<code>
report-type
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045094488464">
</a>
<a class="indexterm" name="idm46045094486976">
</a>
<p>
Displays a report of type
<em class="replaceable">
<code>
report-type
</code>
</em>
for the data node
identified by
<em class="replaceable">
<code>
node_id
</code>
</em>
, or for all
data nodes using
<code class="literal">
ALL
</code>
.
</p>
<p>
Currently, there are three accepted values for
<em class="replaceable">
<code>
report-type
</code>
</em>
:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
<code class="literal">
BackupStatus
</code>
provides a status report
on a cluster backup in progress
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
MemoryUsage
</code>
displays how much data
memory and index memory is being used by each data node as
shown in this example:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-ndbmgm"><div class="docs-select-all right" id="sa76168625"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-ndbmgm"><span class="token prompt">ndb_mgm></span> <span class="token keyword">ALL</span> <span class="token keyword">REPORT</span> <span class="token keyword">MEMORY</span>
<span class="token selector">Node 1:</span> Data usage is 5<span class="token operator">%</span><span class="token punctuation">(</span>177 32K pages of total 3200<span class="token punctuation">)</span>
<span class="token selector">Node 1:</span> Index usage is 0<span class="token operator">%</span><span class="token punctuation">(</span>108 8K pages of total 12832<span class="token punctuation">)</span>
<span class="token selector">Node 2:</span> Data usage is 5<span class="token operator">%</span><span class="token punctuation">(</span>177 32K pages of total 3200<span class="token punctuation">)</span>
<span class="token selector">Node 2:</span> Index usage is 0<span class="token operator">%</span><span class="token punctuation">(</span>108 8K pages of total 12832<span class="token punctuation">)</span></code></pre>
</div>
<p>
This information is also available from the
<a class="link" href="mysql-cluster-ndbinfo-memoryusage.html" title="25.6.17.46 The ndbinfo memoryusage Table">
<code class="literal">
ndbinfo.memoryusage
</code>
</a>
table.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
EventLog
</code>
reports events from the event
log buffers of one or more data nodes.
</p>
</li>
</ul>
</div>
<p>
<em class="replaceable">
<code>
report-type
</code>
</em>
is case-insensitive and
<span class="quote">
“
<span class="quote">
fuzzy
</span>
”
</span>
; for
<code class="literal">
MemoryUsage
</code>
, you
can use
<code class="literal">
MEMORY
</code>
(as shown in the prior
example),
<code class="literal">
memory
</code>
, or even simply
<code class="literal">
MEM
</code>
(or
<code class="literal">
mem
</code>
). You can
abbreviate
<code class="literal">
BackupStatus
</code>
in a similar
fashion.
</p>
</li>
<li class="listitem">
<p>
<a name="ndbclient-restart">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-restart">
<code class="literal">
<em class="replaceable">
<code>
node_id
</code>
</em>
RESTART [-n] [-i] [-a] [-f]
</code>
</a>
</p>
<a class="indexterm" name="idm46045094465648">
</a>
<a class="indexterm" name="idm46045094464160">
</a>
<p>
Restarts the data node identified by
<em class="replaceable">
<code>
node_id
</code>
</em>
(or all data nodes).
</p>
<p>
Using the
<code class="option">
-i
</code>
option with
<code class="literal">
RESTART
</code>
causes the data node to perform an
initial restart; that is, the node's file system is
deleted and recreated. The effect is the same as that obtained
from stopping the data node process and then starting it again
using
<a class="link" href="mysql-cluster-programs-ndbd.html" title="25.5.1 ndbd — The NDB Cluster Data Node Daemon">
<span class="command">
<strong>
ndbd
</strong>
</span>
</a>
<a class="link" href="mysql-cluster-programs-ndbd.html#option_ndbd_initial">
<code class="option">
--initial
</code>
</a>
from the system shell.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
Backup files and Disk Data files are not removed when this
option is used.
</p>
</div>
<p>
Using the
<code class="option">
-n
</code>
option causes the data node
process to be restarted, but the data node is not actually
brought online until the appropriate
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-start">
<code class="literal">
START
</code>
</a>
command is issued.
The effect of this option is the same as that obtained from
stopping the data node and then starting it again using
<a class="link" href="mysql-cluster-programs-ndbd.html" title="25.5.1 ndbd — The NDB Cluster Data Node Daemon">
<span class="command">
<strong>
ndbd
</strong>
</span>
</a>
<a class="link" href="mysql-cluster-programs-ndbd.html#option_ndbd_nostart">
<code class="option">
--nostart
</code>
</a>
or
<a class="link" href="mysql-cluster-programs-ndbd.html" title="25.5.1 ndbd — The NDB Cluster Data Node Daemon">
<span class="command">
<strong>
ndbd
</strong>
</span>
</a>
<code class="option">
-n
</code>
from the system
shell.
</p>
<p>
Using the
<code class="option">
-a
</code>
causes all current transactions
relying on this node to be aborted. No GCP check is done when
the node rejoins the cluster.
</p>
<p>
Normally,
<code class="literal">
RESTART
</code>
fails if taking the node
offline would result in an incomplete cluster. The
<code class="option">
-f
</code>
option forces the node to restart without
checking for this. If this option is used and the result is an
incomplete cluster, the entire cluster is restarted.
</p>
</li>
<li class="listitem">
<p>
<a name="ndbclient-show">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-show">
<code class="literal">
SHOW
</code>
</a>
</p>
<a class="indexterm" name="idm46045094445840">
</a>
<a class="indexterm" name="idm46045094444352">
</a>
<p>
Displays basic information about the cluster and cluster
nodes. For all nodes, the output includes the node's ID,
type, and
<code class="literal">
NDB
</code>
software version. If the node
is connected, its IP address is also shown; otherwise the
output shows
<code class="literal">
not connected, accepting connect from
<em class="replaceable">
<code>
ip_address
</code>
</em>
</code>
, with
<code class="literal">
any host
</code>
used for nodes that are permitted
to connect from any address.
</p>
<p>
In addition, for data nodes, the output includes
<code class="literal">
starting
</code>
if the node has not yet started,
and shows the node group of which the node is a member. If the
data node is acting as the master node, this is indicated with
an asterisk (
<code class="literal">
*
</code>
).
</p>
<p>
Consider a cluster whose configuration file includes the
information shown here (possible additional settings are
omitted for clarity):
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-ini"><div class="docs-select-all right" id="sa977655"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-ini"><span class="token selector">[ndbd default]</span>
<span class="token constant">DataMemory</span><span class="token attr-value"><span class="token punctuation">=</span> 128G</span>
<span class="token constant">NoOfReplicas</span><span class="token attr-value"><span class="token punctuation">=</span> 2</span>
<span class="token selector">[ndb_mgmd]</span>
<span class="token constant">NodeId</span><span class="token attr-value"><span class="token punctuation">=</span>50</span>
<span class="token constant">HostName</span><span class="token attr-value"><span class="token punctuation">=</span>198.51.100.150</span>
<span class="token selector">[ndbd]</span>
<span class="token constant">NodeId</span><span class="token attr-value"><span class="token punctuation">=</span>5</span>
<span class="token constant">HostName</span><span class="token attr-value"><span class="token punctuation">=</span>198.51.100.10</span>
<span class="token constant">DataDir</span><span class="token attr-value"><span class="token punctuation">=</span>/var/lib/mysql-cluster</span>
<span class="token selector">[ndbd]</span>
<span class="token constant">NodeId</span><span class="token attr-value"><span class="token punctuation">=</span>6</span>
<span class="token constant">HostName</span><span class="token attr-value"><span class="token punctuation">=</span>198.51.100.20</span>
<span class="token constant">DataDir</span><span class="token attr-value"><span class="token punctuation">=</span>/var/lib/mysql-cluster</span>
<span class="token selector">[ndbd]</span>
<span class="token constant">NodeId</span><span class="token attr-value"><span class="token punctuation">=</span>7</span>
<span class="token constant">HostName</span><span class="token attr-value"><span class="token punctuation">=</span>198.51.100.30</span>
<span class="token constant">DataDir</span><span class="token attr-value"><span class="token punctuation">=</span>/var/lib/mysql-cluster</span>
<span class="token selector">[ndbd]</span>
<span class="token constant">NodeId</span><span class="token attr-value"><span class="token punctuation">=</span>8</span>
<span class="token constant">HostName</span><span class="token attr-value"><span class="token punctuation">=</span>198.51.100.40</span>
<span class="token constant">DataDir</span><span class="token attr-value"><span class="token punctuation">=</span>/var/lib/mysql-cluster</span>
<span class="token selector">[mysqld]</span>
<span class="token constant">NodeId</span><span class="token attr-value"><span class="token punctuation">=</span>100</span>
<span class="token constant">HostName</span><span class="token attr-value"><span class="token punctuation">=</span>198.51.100.100</span>
<span class="token selector">[api]</span>
<span class="token constant">NodeId</span><span class="token attr-value"><span class="token punctuation">=</span>101</span></code></pre>
</div>
<p>
After this cluster (including one SQL node) has been started,
<code class="literal">
SHOW
</code>
displays the following output:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-ndbmgm"><div class="docs-select-all right" id="sa72019595"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-ndbmgm"><span class="token prompt">ndb_mgm></span> <span class="token keyword">SHOW</span>
Connected to Management Server at<span class="token operator">:</span> localhost<span class="token operator">:</span>1186 <span class="token punctuation">(</span>using cleartext<span class="token punctuation">)</span>
Cluster Configuration
<span class="token operator">--</span><span class="token operator">--</span><span class="token operator">--</span><span class="token operator">--</span><span class="token operator">--</span><span class="token operator">--</span><span class="token operator">--</span><span class="token operator">--</span><span class="token operator">--</span><span class="token operator">--</span><span class="token operator">-</span>
<span class="token selector">[ndbd(NDB)]</span> 4 node<span class="token punctuation">(</span>s<span class="token punctuation">)</span>
id<span class="token operator">=</span>5 @198<span class="token punctuation">.</span>51<span class="token punctuation">.</span>100<span class="token punctuation">.</span>10 <span class="token punctuation">(</span>mysql<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0 ndb<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0<span class="token punctuation">,</span> Nodegroup<span class="token operator">:</span> 0<span class="token punctuation">,</span> <span class="token operator">*</span><span class="token punctuation">)</span>
id<span class="token operator">=</span>6 @198<span class="token punctuation">.</span>51<span class="token punctuation">.</span>100<span class="token punctuation">.</span>20 <span class="token punctuation">(</span>mysql<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0 ndb<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0<span class="token punctuation">,</span> Nodegroup<span class="token operator">:</span> 0<span class="token punctuation">)</span>
id<span class="token operator">=</span>7 @198<span class="token punctuation">.</span>51<span class="token punctuation">.</span>100<span class="token punctuation">.</span>30 <span class="token punctuation">(</span>mysql<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0 ndb<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0<span class="token punctuation">,</span> Nodegroup<span class="token operator">:</span> 1<span class="token punctuation">)</span>
id<span class="token operator">=</span>8 @198<span class="token punctuation">.</span>51<span class="token punctuation">.</span>100<span class="token punctuation">.</span>40 <span class="token punctuation">(</span>mysql<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0 ndb<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0<span class="token punctuation">,</span> Nodegroup<span class="token operator">:</span> 1<span class="token punctuation">)</span>
<span class="token selector">[ndb_mgmd(MGM)]</span> 1 node<span class="token punctuation">(</span>s<span class="token punctuation">)</span>
id<span class="token operator">=</span>50 @198<span class="token punctuation">.</span>51<span class="token punctuation">.</span>100<span class="token punctuation">.</span>150 <span class="token punctuation">(</span>mysql<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0 ndb<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0<span class="token punctuation">)</span>
<span class="token selector">[mysqld(API)]</span> 2 node<span class="token punctuation">(</span>s<span class="token punctuation">)</span>
id<span class="token operator">=</span>100 @198<span class="token punctuation">.</span>51<span class="token punctuation">.</span>100<span class="token punctuation">.</span>100 <span class="token punctuation">(</span>mysql<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0 ndb<span class="token operator">-</span>8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>0<span class="token punctuation">)</span>
id<span class="token operator">=</span>101 <span class="token punctuation">(</span>not connected<span class="token punctuation">,</span> accepting connect from any host<span class="token punctuation">)</span></code></pre>
</div>
<p>
The output from this command also indicates when the cluster
is in single user mode (see the description of the
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-enter-single-user-mode">
<code class="literal">
ENTER SINGLE USER MODE
</code>
</a>
command, as well as
<a class="xref" href="mysql-cluster-single-user-mode.html" title="25.6.6 NDB Cluster Single User Mode">
Section 25.6.6, “NDB Cluster Single User Mode”
</a>
). It also
indicates which API or SQL node has exclusive access when this
mode is in effect.
</p>
</li>
<li class="listitem">
<p>
<a name="ndbclient-shutdown">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-shutdown">
<code class="literal">
SHUTDOWN
</code>
</a>
</p>
<a class="indexterm" name="idm46045094427104">
</a>
<a class="indexterm" name="idm46045094425616">
</a>
<p>
Shuts down all cluster data nodes and management nodes. To
exit the management client after this has been done, use
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-quit">
<code class="literal">
EXIT
</code>
</a>
or
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-quit">
<code class="literal">
QUIT
</code>
</a>
.
</p>
<p>
This command does
<span class="emphasis">
<em>
not
</em>
</span>
shut down any SQL
nodes or API nodes that are connected to the cluster.
</p>
</li>
<li class="listitem">
<p>
<a name="ndbclient-start">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-start">
<code class="literal">
<em class="replaceable">
<code>
node_id
</code>
</em>
START
</code>
</a>
</p>
<a class="indexterm" name="idm46045094417968">
</a>
<a class="indexterm" name="idm46045094416480">
</a>
<p>
Brings online the data node identified by
<em class="replaceable">
<code>
node_id
</code>
</em>
(or all data nodes).
</p>
<p>
<code class="literal">
ALL START
</code>
works on all data nodes only, and
does not affect management nodes.
</p>
<div class="important" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Important
</div>
<p>
To use this command to bring a data node online, the data
node must have been started using
<a class="link" href="mysql-cluster-programs-ndbd.html#option_ndbd_nostart">
<code class="option">
--nostart
</code>
</a>
or
<code class="option">
-n
</code>
.
</p>
</div>
</li>
<li class="listitem">
<p>
<a name="ndbclient-status">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-status">
<code class="literal">
<em class="replaceable">
<code>
node_id
</code>
</em>
STATUS
</code>
</a>
</p>
<a class="indexterm" name="idm46045094408320">
</a>
<a class="indexterm" name="idm46045094406832">
</a>
<p>
Displays status information for the data node identified by
<em class="replaceable">
<code>
node_id
</code>
</em>
(or for all data nodes).
</p>
<p>
Possible node status values include
<code class="literal">
UNKNOWN
</code>
,
<code class="literal">
NO_CONTACT
</code>
,
<code class="literal">
NOT_STARTED
</code>
,
<code class="literal">
STARTING
</code>
,
<code class="literal">
STARTED
</code>
,
<code class="literal">
SHUTTING_DOWN
</code>
,
and
<code class="literal">
RESTARTING
</code>
.
</p>
<p>
The output from this command also indicates when the cluster
is in single user mode.
</p>
</li>
<li class="listitem">
<p>
<a name="ndbclient-stop">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-stop">
<code class="literal">
<em class="replaceable">
<code>
node_id
</code>
</em>
STOP [-a] [-f]
</code>
</a>
</p>
<a class="indexterm" name="idm46045094396240">
</a>
<a class="indexterm" name="idm46045094394752">
</a>
<p>
Stops the data or management node identified by
<em class="replaceable">
<code>
node_id
</code>
</em>
.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
<code class="literal">
ALL STOP
</code>
works to stop all data nodes
only, and does not affect management nodes.
</p>
</div>
<p>
A node affected by this command disconnects from the cluster,
and its associated
<a class="link" href="mysql-cluster-programs-ndbd.html" title="25.5.1 ndbd — The NDB Cluster Data Node Daemon">
<span class="command">
<strong>
ndbd
</strong>
</span>
</a>
or
<a class="link" href="mysql-cluster-programs-ndb-mgmd.html" title="25.5.4 ndb_mgmd — The NDB Cluster Management Server Daemon">
<span class="command">
<strong>
ndb_mgmd
</strong>
</span>
</a>
process terminates.
</p>
<p>
The
<code class="option">
-a
</code>
option causes the node to be stopped
immediately, without waiting for the completion of any pending
transactions.
</p>
<p>
Normally,
<code class="literal">
STOP
</code>
fails if the result would
cause an incomplete cluster. The
<code class="option">
-f
</code>
option
forces the node to shut down without checking for this. If
this option is used and the result is an incomplete cluster,
the cluster immediately shuts down.
</p>
<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Warning
</div>
<p>
Use of the
<code class="option">
-a
</code>
option also disables the
safety check otherwise performed when
<code class="literal">
STOP
</code>
is invoked to insure that stopping
the node does not cause an incomplete cluster. In other
words, you should exercise extreme care when using the
<code class="option">
-a
</code>
option with the
<code class="literal">
STOP
</code>
command, due to the fact that this option makes it possible
for the cluster to undergo a forced shutdown because it no
longer has a complete copy of all data stored in
<a class="link" href="mysql-cluster.html" title="Chapter 25 MySQL NDB Cluster 8.4">
<code class="literal">
NDB
</code>
</a>
.
</p>
</div>
</li>
<li class="listitem">
<p>
<a name="ndbclient-tls-info">
</a>
<a class="link" href="mysql-cluster-mgm-client-commands.html#ndbclient-tls-info">
<code class="literal">
TLS INFO
</code>
</a>
</p>
<a class="indexterm" name="idm46045094378320">
</a>
<a class="indexterm" name="idm46045094376832">
</a>
<p>
Displays cluster TLS information such as whether the current
connection is using TLS, TLS certificates currently known to
the management node, and the management node's counts of
total connections, connections upgraded to TLS, and
authorization failures. Sample output is shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-terminal"><div class="docs-select-all right" id="sa56830135"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal">ndb_mgm> TLS INFO
Session ID<span class="token punctuation">:</span> 1
Peer address<span class="token punctuation">:</span> 127<span class="token punctuation">.</span>0<span class="token punctuation">.</span>0<span class="token punctuation">.</span>1
Certificate name<span class="token punctuation">:</span> NDB Management Node Jun 2023
Certificate serial<span class="token punctuation">:</span> B5<span class="token punctuation">:</span>23<span class="token punctuation">:</span>8F<span class="token punctuation">:</span>D1<span class="token punctuation">:</span>11<span class="token punctuation">:</span>85<span class="token punctuation">:</span>E5<span class="token punctuation">:</span>93<span class="token punctuation">:</span>ED
Certificate expires<span class="token punctuation">:</span> 23-Nov-2023
Server statistics since restart
Total accepted connections<span class="token punctuation">:</span> 6
Total connections upgraded to TLS<span class="token punctuation">:</span> 2
Current connections<span class="token punctuation">:</span> 3
Current connections using TLS<span class="token punctuation">:</span> 2
Authorization failures<span class="token punctuation">:</span> 0
ndb_mgm></code></pre>
</div>
<p>
For more information, see
<a class="xref" href="mysql-cluster-tls.html" title="25.6.15 TLS Link Encryption for NDB Cluster">
Section 25.6.15, “TLS Link Encryption for NDB Cluster”
</a>
.
</p>
</li>
</ul>
</div>
<p>
<b>
Additional commands.
</b>
A number of other commands available in the
<a class="link" href="mysql-cluster-programs-ndb-mgm.html" title="25.5.5 ndb_mgm — The NDB Cluster Management Client">
<span class="command">
<strong>
ndb_mgm
</strong>
</span>
</a>
client are described elsewhere, as
shown in the following list:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="link" href="mysql-cluster-backup-using-management-client.html" title="25.6.8.2 Using The NDB Cluster Management Client to Create a Backup">
<code class="literal">
START BACKUP
</code>
</a>
is used to
perform an online backup in the
<a class="link" href="mysql-cluster-programs-ndb-mgm.html" title="25.5.5 ndb_mgm — The NDB Cluster Management Client">
<span class="command">
<strong>
ndb_mgm
</strong>
</span>
</a>
client; the
<a class="link" href="mysql-cluster-backup-using-management-client.html#ndbclient-abort-backup" title="Cancelling backups">
<code class="literal">
ABORT BACKUP
</code>
</a>
command is used to cancel a backup already in progress. For
more information, see
<a class="xref" href="mysql-cluster-backup.html" title="25.6.8 Online Backup of NDB Cluster">
Section 25.6.8, “Online Backup of NDB Cluster”
</a>
.
</p>
</li>
<li class="listitem">
<p>
The
<a class="link" href="mysql-cluster-logging-management-commands.html" title="25.6.3.1 NDB Cluster Logging Management Commands">
<code class="literal">
CLUSTERLOG
</code>
</a>
command is
used to perform various logging functions. See
<a class="xref" href="mysql-cluster-event-reports.html" title="25.6.3 Event Reports Generated in NDB Cluster">
Section 25.6.3, “Event Reports Generated in NDB Cluster”
</a>
, for more
information and examples.
<code class="literal">
NODELOG DEBUG
</code>
activates or deactivates debug printouts in node logs, as
described previously in this section.
</p>
</li>
<li class="listitem">
<p>
For testing and diagnostics work, the client supports a
<a class="ulink" href="/doc/ndb-internals/en/dump-commands.html" target="_top">
<code class="literal">
DUMP
</code>
</a>
command which can be
used to execute internal commands on the cluster. It should
never be used in a production setting unless directed to do so
by MySQL Support. For more information, see
<a class="ulink" href="/doc/ndb-internals/en/dump-commands.html" target="_top">
NDB Cluster Management Client DUMP Commands
</a>
.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-disk-data.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="mysql-cluster-disk-data">
</a>
25.6.11 NDB Cluster Disk Data Tables
</h3>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="mysql-cluster-disk-data-objects.html">
25.6.11.1 NDB Cluster Disk Data Objects
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="mysql-cluster-disk-data-storage-requirements.html">
25.6.11.2 NDB Cluster Disk Data Storage Requirements
</a>
</span>
</dt>
</dl>
</div>
<a class="indexterm" name="idm46045091734176">
</a>
<a class="indexterm" name="idm46045091733136">
</a>
<a class="indexterm" name="idm46045091731232">
</a>
<p>
NDB Cluster supports storing nonindexed columns of
<a class="link" href="mysql-cluster.html" title="Chapter 25 MySQL NDB Cluster 8.4">
<code class="literal">
NDB
</code>
</a>
tables on disk, rather than in
RAM. Column data and logging metadata are kept in data files and
undo log files, conceptualized as tablespaces and log file groups,
as described in the next section—see
<a class="xref" href="mysql-cluster-disk-data-objects.html" title="25.6.11.1 NDB Cluster Disk Data Objects">
Section 25.6.11.1, “NDB Cluster Disk Data Objects”
</a>
.
</p>
<p>
NDB Cluster Disk Data performance can be influenced by a number of
configuration parameters. For information about these parameters
and their effects, see
<a class="xref" href="mysql-cluster-ndbd-definition.html#mysql-cluster-ndbd-definition-disk-data-parameters" title="Disk Data Configuration Parameters">
Disk Data Configuration Parameters
</a>
,
and
<a class="xref" href="mysql-cluster-ndbd-definition.html#mysql-cluster-ndbd-definition-gcp-stop-errors" title="Disk Data and GCP Stop errors">
Disk Data and GCP Stop errors
</a>
.
</p>
<p>
You should also set the
<a class="link" href="mysql-cluster-ndbd-definition.html#ndbparam-ndbd-diskdatausingsamedisk">
<code class="literal">
DiskDataUsingSameDisk
</code>
</a>
data
node configuration parameter to
<code class="literal">
false
</code>
when
using separate disks for Disk Data files.
</p>
<p>
For more information, see the following:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="xref" href="mysql-cluster-ndbd-definition.html#mysql-cluster-ndbd-disk-data-filesystem-parameters" title="Disk Data file system parameters">
Disk Data file system parameters
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="mysql-cluster-ndbd-definition.html#mysql-cluster-ndbd-definition-disk-data-latency-parameters" title="Disk Data latency parameters">
Disk Data latency parameters
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="mysql-cluster-ndbinfo-diskstat.html" title="25.6.17.32 The ndbinfo diskstat Table">
Section 25.6.17.32, “The ndbinfo diskstat Table”
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="mysql-cluster-ndbinfo-diskstats-1sec.html" title="25.6.17.33 The ndbinfo diskstats_1sec Table">
Section 25.6.17.33, “The ndbinfo diskstats_1sec Table”
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="mysql-cluster-ndbinfo-pgman-time-track-stats.html" title="25.6.17.50 The ndbinfo pgman_time_track_stats Table">
Section 25.6.17.50, “The ndbinfo pgman_time_track_stats Table”
</a>
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/solaris-installation-pkg.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="solaris-installation-pkg">
</a>
2.7.1 Installing MySQL on Solaris Using a Solaris PKG
</h3>
</div>
</div>
</div>
<p>
You can install MySQL on Solaris using a binary package of the
native Solaris PKG format instead of the binary tarball
distribution.
</p>
<p>
To use this package, download the corresponding
<code class="filename">
mysql-VERSION-solaris11-PLATFORM.pkg.gz
</code>
file,
then uncompress it. For example:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa90292275"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token prompt">$> </span><span class="token command">gunzip</span> mysql-<em class="replaceable">8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>3</em>-solaris11-x86_64<span class="token punctuation">.</span>pkg<span class="token punctuation">.</span>gz</code></pre>
</div>
<p>
To install a new package, use
<span class="command">
<strong>
pkgadd
</strong>
</span>
and follow
the onscreen prompts. You must have root privileges to perform
this operation:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-terminal"><div class="docs-select-all right" id="sa75409706"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token prompt">$> </span><span class="token command">pkgadd</span> <span class="token property">-d</span> mysql-<em class="replaceable">8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>3</em>-solaris11-x86_64<span class="token punctuation">.</span>pkg
The following packages are available<span class="token punctuation">:</span>
1 mysql MySQL Community Server <span class="token punctuation">(</span>GPL<span class="token punctuation">)</span>
<span class="token punctuation">(</span>i86pc<span class="token punctuation">)</span> 8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>3
Select package<span class="token punctuation">(</span>s<span class="token punctuation">)</span> you wish to process <span class="token punctuation">(</span>or <span class="token atrule">'all'</span> to process
all packages<span class="token punctuation">)</span><span class="token punctuation">.</span> <span class="token punctuation">(</span>default<span class="token punctuation">:</span> all<span class="token punctuation">)</span> <span class="token punctuation">[</span>?<span class="token punctuation">,</span>??<span class="token punctuation">,</span>q<span class="token punctuation">]</span><span class="token punctuation">:</span></code></pre>
</div>
<p>
The PKG installer installs all of the files and tools needed, and
then initializes your database if one does not exist. To complete
the installation, you should set the root password for MySQL as
provided in the instructions at the end of the installation.
Alternatively, you can run the
<a class="link" href="mysql-secure-installation.html" title="6.4.2 mysql_secure_installation — Improve MySQL Installation Security">
<span class="command">
<strong>
mysql_secure_installation
</strong>
</span>
</a>
script that comes
with the installation.
</p>
<p>
By default, the PKG package installs MySQL under the root path
<code class="filename">
/opt/mysql
</code>
. You can change only the
installation root path when using
<span class="command">
<strong>
pkgadd
</strong>
</span>
, which
can be used to install MySQL in a different Solaris zone. If you
need to install in a specific directory, use a binary
<span class="command">
<strong>
tar
</strong>
</span>
file distribution.
</p>
<p>
The
<code class="literal">
pkg
</code>
installer copies a suitable startup
script for MySQL into
<code class="literal">
/etc/init.d/mysql
</code>
. To
enable MySQL to startup and shutdown automatically, you should
create a link between this file and the init script directories.
For example, to ensure safe startup and shutdown of MySQL you
could use the following commands to add the right links:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-terminal"><div class="docs-select-all right" id="sa39225034"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token prompt">$> </span><span class="token command">ln</span> /etc/init<span class="token punctuation">.</span>d/mysql /etc/rc3<span class="token punctuation">.</span>d/S91mysql
<span class="token prompt">$> </span><span class="token command">ln</span> /etc/init<span class="token punctuation">.</span>d/mysql /etc/rc0<span class="token punctuation">.</span>d/K02mysql</code></pre>
</div>
<p>
To remove MySQL, the installed package name is
<code class="literal">
mysql
</code>
. You can use this in combination with the
<span class="command">
<strong>
pkgrm
</strong>
</span>
command to remove the installation.
</p>
<p>
To upgrade when using the Solaris package file format, you must
remove the existing installation before installing the updated
package. Removal of the package does not delete the existing
database information, only the server, binaries and support files.
The typical upgrade sequence is therefore:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-terminal"><div class="docs-select-all right" id="sa56842580"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token prompt">$> </span><span class="token command">mysqladmin</span> shutdown
<span class="token prompt">$> </span><span class="token command">pkgrm</span> mysql
<span class="token prompt">$> </span><span class="token command">pkgadd</span> <span class="token property">-d</span> mysql-<em class="replaceable">8<span class="token punctuation">.</span>4<span class="token punctuation">.</span>3</em>-solaris11-x86_64<span class="token punctuation">.</span>pkg
<span class="token prompt">$> </span><span class="token command">mysqld_safe</span> &</code></pre>
</div>
<p>
You should check the notes in
<a class="xref" href="upgrading.html" title="Chapter 3 Upgrading MySQL">
Chapter 3,
<i>
Upgrading MySQL
</i>
</a>
before
performing any upgrade.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/innodb-error-handling.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="innodb-error-handling">
</a>
17.20.5 InnoDB Error Handling
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045148856544">
</a>
<a class="indexterm" name="idm46045148854640">
</a>
<p>
The following items describe how
<code class="literal">
InnoDB
</code>
performs error handling.
<code class="literal">
InnoDB
</code>
sometimes rolls
back only the statement that failed, other times it rolls back the
entire transaction.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
If you run out of file space in a
<a class="link" href="glossary.html#glos_tablespace" title="tablespace">
tablespace
</a>
, a MySQL
<code class="literal">
Table is full
</code>
error occurs and
<code class="literal">
InnoDB
</code>
rolls back the SQL statement.
</p>
</li>
<li class="listitem">
<p>
A transaction
<a class="link" href="glossary.html#glos_deadlock" title="deadlock">
deadlock
</a>
causes
<code class="literal">
InnoDB
</code>
to
<a class="link" href="glossary.html#glos_rollback" title="rollback">
roll back
</a>
the entire
<a class="link" href="glossary.html#glos_transaction" title="transaction">
transaction
</a>
. Retry the
entire transaction when this happens.
</p>
<p>
A lock wait timeout causes
<code class="literal">
InnoDB
</code>
to roll
back the current statement (the statement that was waiting for
the lock and encountered the timeout). To have the entire
transaction roll back, start the server with
<a class="link" href="innodb-parameters.html#sysvar_innodb_rollback_on_timeout">
<code class="option">
--innodb-rollback-on-timeout
</code>
</a>
enabled. Retry the statement if using the default behavior, or
the entire transaction if
<a class="link" href="innodb-parameters.html#sysvar_innodb_rollback_on_timeout">
<code class="option">
--innodb-rollback-on-timeout
</code>
</a>
is
enabled.
</p>
<p>
Both deadlocks and lock wait timeouts are normal on busy
servers and it is necessary for applications to be aware that
they may happen and handle them by retrying. You can make them
less likely by doing as little work as possible between the
first change to data during a transaction and the commit, so
the locks are held for the shortest possible time and for the
smallest possible number of rows. Sometimes splitting work
between different transactions may be practical and helpful.
</p>
</li>
<li class="listitem">
<p>
A duplicate-key error rolls back the SQL statement, if you
have not specified the
<code class="literal">
IGNORE
</code>
option in
your statement.
</p>
</li>
<li class="listitem">
<p>
A
<code class="literal">
row too long error
</code>
rolls back the SQL
statement.
</p>
</li>
<li class="listitem">
<p>
Other errors are mostly detected by the MySQL layer of code
(above the
<code class="literal">
InnoDB
</code>
storage engine level),
and they roll back the corresponding SQL statement. Locks are
not released in a rollback of a single SQL statement.
</p>
</li>
</ul>
</div>
<p>
During implicit rollbacks, as well as during the execution of an
explicit
<a class="link" href="commit.html" title="15.3.1 START TRANSACTION, COMMIT, and ROLLBACK Statements">
<code class="literal">
ROLLBACK
</code>
</a>
SQL
statement,
<a class="link" href="show-processlist.html" title="15.7.7.31 SHOW PROCESSLIST Statement">
<code class="literal">
SHOW PROCESSLIST
</code>
</a>
displays
<code class="literal">
Rolling back
</code>
in the
<code class="literal">
State
</code>
column for the relevant connection.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/charset-database.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="charset-database">
</a>
12.3.3 Database Character Set and Collation
</h3>
</div>
</div>
</div>
<p>
Every database has a database character set and a database
collation. The
<a class="link" href="create-database.html" title="15.1.12 CREATE DATABASE Statement">
<code class="literal">
CREATE DATABASE
</code>
</a>
and
<a class="link" href="alter-database.html" title="15.1.2 ALTER DATABASE Statement">
<code class="literal">
ALTER DATABASE
</code>
</a>
statements
have optional clauses for specifying the database character set
and collation:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa22514143"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">DATABASE</span> <em class="replaceable">db_name</em>
<span class="token punctuation">[</span><span class="token punctuation">[</span><span class="token keyword">DEFAULT</span><span class="token punctuation">]</span> <span class="token keyword">CHARACTER</span> <span class="token keyword">SET</span> <em class="replaceable">charset_name</em><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token punctuation">[</span><span class="token keyword">DEFAULT</span><span class="token punctuation">]</span> <span class="token keyword">COLLATE</span> <em class="replaceable">collation_name</em><span class="token punctuation">]</span>
<span class="token keyword">ALTER</span> <span class="token keyword">DATABASE</span> <em class="replaceable">db_name</em>
<span class="token punctuation">[</span><span class="token punctuation">[</span><span class="token keyword">DEFAULT</span><span class="token punctuation">]</span> <span class="token keyword">CHARACTER</span> <span class="token keyword">SET</span> <em class="replaceable">charset_name</em><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token punctuation">[</span><span class="token keyword">DEFAULT</span><span class="token punctuation">]</span> <span class="token keyword">COLLATE</span> <em class="replaceable">collation_name</em><span class="token punctuation">]</span></code></pre>
</div>
<p>
The keyword
<code class="literal">
SCHEMA
</code>
can be used instead of
<code class="literal">
DATABASE
</code>
.
</p>
<p>
The
<code class="literal">
CHARACTER SET
</code>
and
<code class="literal">
COLLATE
</code>
clauses make it possible to create
databases with different character sets and collations on the
same MySQL server.
</p>
<p>
Database options are stored in the data dictionary and can be
examined by checking the Information Schema
<a class="link" href="information-schema-schemata-table.html" title="28.3.31 The INFORMATION_SCHEMA SCHEMATA Table">
<code class="literal">
SCHEMATA
</code>
</a>
table.
</p>
<p>
Example:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa50711255"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">DATABASE</span> <em class="replaceable">db_name</em> <span class="token keyword">CHARACTER</span> <span class="token keyword">SET</span> latin1 <span class="token keyword">COLLATE</span> latin1_swedish_ci<span class="token punctuation">;</span></code></pre>
</div>
<p>
MySQL chooses the database character set and database collation
in the following manner:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
If both
<code class="literal">
CHARACTER SET
<em class="replaceable">
<code>
charset_name
</code>
</em>
</code>
and
<code class="literal">
COLLATE
<em class="replaceable">
<code>
collation_name
</code>
</em>
</code>
are
specified, character set
<em class="replaceable">
<code>
charset_name
</code>
</em>
and collation
<em class="replaceable">
<code>
collation_name
</code>
</em>
are used.
</p>
</li>
<li class="listitem">
<p>
If
<code class="literal">
CHARACTER SET
<em class="replaceable">
<code>
charset_name
</code>
</em>
</code>
is
specified without
<code class="literal">
COLLATE
</code>
, character set
<em class="replaceable">
<code>
charset_name
</code>
</em>
and its default
collation are used. To see the default collation for each
character set, use the
<a class="link" href="show-character-set.html" title="15.7.7.4 SHOW CHARACTER SET Statement">
<code class="literal">
SHOW CHARACTER
SET
</code>
</a>
statement or query the
<code class="literal">
INFORMATION_SCHEMA
</code>
<a class="link" href="information-schema-character-sets-table.html" title="28.3.4 The INFORMATION_SCHEMA CHARACTER_SETS Table">
<code class="literal">
CHARACTER_SETS
</code>
</a>
table.
</p>
</li>
<li class="listitem">
<p>
If
<code class="literal">
COLLATE
<em class="replaceable">
<code>
collation_name
</code>
</em>
</code>
is
specified without
<code class="literal">
CHARACTER SET
</code>
, the
character set associated with
<em class="replaceable">
<code>
collation_name
</code>
</em>
and collation
<em class="replaceable">
<code>
collation_name
</code>
</em>
are used.
</p>
</li>
<li class="listitem">
<p>
Otherwise (neither
<code class="literal">
CHARACTER SET
</code>
nor
<code class="literal">
COLLATE
</code>
is specified), the server
character set and server collation are used.
</p>
</li>
</ul>
</div>
<p>
The character set and collation for the default database can be
determined from the values of the
<a class="link" href="server-system-variables.html#sysvar_character_set_database">
<code class="literal">
character_set_database
</code>
</a>
and
<a class="link" href="server-system-variables.html#sysvar_collation_database">
<code class="literal">
collation_database
</code>
</a>
system
variables. The server sets these variables whenever the default
database changes. If there is no default database, the variables
have the same value as the corresponding server-level system
variables,
<a class="link" href="server-system-variables.html#sysvar_character_set_server">
<code class="literal">
character_set_server
</code>
</a>
and
<a class="link" href="server-system-variables.html#sysvar_collation_server">
<code class="literal">
collation_server
</code>
</a>
.
</p>
<p>
To see the default character set and collation for a given
database, use these statements:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa78625744"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">USE</span> <em class="replaceable">db_name</em><span class="token punctuation">;</span>
<span class="token keyword">SELECT</span> <span class="token variable">@@character_set_database</span><span class="token punctuation">,</span> <span class="token variable">@@collation_database</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
Alternatively, to display the values without changing the
default database:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa56471871"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> DEFAULT_CHARACTER_SET_NAME<span class="token punctuation">,</span> DEFAULT_COLLATION_NAME
<span class="token keyword">FROM</span> INFORMATION_SCHEMA<span class="token punctuation">.</span>SCHEMATA <span class="token keyword">WHERE</span> <span class="token keyword">SCHEMA_NAME</span> <span class="token operator">=</span> <span class="token string">'<em class="replaceable">db_name</em>'</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
The database character set and collation affect these aspects of
server operation:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
For
<a class="link" href="create-table.html" title="15.1.20 CREATE TABLE Statement">
<code class="literal">
CREATE TABLE
</code>
</a>
statements,
the database character set and collation are used as default
values for table definitions if the table character set and
collation are not specified. To override this, provide
explicit
<code class="literal">
CHARACTER SET
</code>
and
<code class="literal">
COLLATE
</code>
table options.
</p>
</li>
<li class="listitem">
<p>
For
<a class="link" href="load-data.html" title="15.2.9 LOAD DATA Statement">
<code class="literal">
LOAD DATA
</code>
</a>
statements that
include no
<code class="literal">
CHARACTER SET
</code>
clause, the
server uses the character set indicated by the
<a class="link" href="server-system-variables.html#sysvar_character_set_database">
<code class="literal">
character_set_database
</code>
</a>
system variable to interpret the information in the file. To
override this, provide an explicit
<code class="literal">
CHARACTER
SET
</code>
clause.
</p>
</li>
<li class="listitem">
<p>
For stored routines (procedures and functions), the database
character set and collation in effect at routine creation
time are used as the character set and collation of
character data parameters for which the declaration includes
no
<code class="literal">
CHARACTER SET
</code>
or a
<code class="literal">
COLLATE
</code>
attribute. To override this,
provide
<code class="literal">
CHARACTER SET
</code>
and
<code class="literal">
COLLATE
</code>
explicitly.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-filtering.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="performance-schema-filtering">
</a>
29.4.2 Performance Schema Event Filtering
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045075538064">
</a>
<a class="indexterm" name="idm46045075536576">
</a>
<a class="indexterm" name="idm46045075535088">
</a>
<p>
Events are processed in a producer/consumer fashion:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Instrumented code is the source for events and produces
events to be collected. The
<a class="link" href="performance-schema-setup-instruments-table.html" title="29.12.2.3 The setup_instruments Table">
<code class="literal">
setup_instruments
</code>
</a>
table lists
the instruments for which events can be collected, whether
they are enabled, and (for enabled instruments) whether to
collect timing information:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa34038690"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token keyword">NAME</span><span class="token punctuation">,</span> ENABLED<span class="token punctuation">,</span> TIMED
<span class="token keyword">FROM</span> performance_schema<span class="token punctuation">.</span>setup_instruments<span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> NAME <span class="token punctuation">|</span> ENABLED <span class="token punctuation">|</span> TIMED <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span>
<span class="token output"><span class="token punctuation">|</span> wait/synch/mutex/sql/LOCK_global_read_lock <span class="token punctuation">|</span> YES <span class="token punctuation">|</span> YES <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> wait/synch/mutex/sql/LOCK_global_system_variables <span class="token punctuation">|</span> YES <span class="token punctuation">|</span> YES <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> wait/synch/mutex/sql/LOCK_lock_db <span class="token punctuation">|</span> YES <span class="token punctuation">|</span> YES <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> wait/synch/mutex/sql/LOCK_manager <span class="token punctuation">|</span> YES <span class="token punctuation">|</span> YES <span class="token punctuation">|</span></span>
<span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span></code></pre>
</div>
<p>
The
<a class="link" href="performance-schema-setup-instruments-table.html" title="29.12.2.3 The setup_instruments Table">
<code class="literal">
setup_instruments
</code>
</a>
table
provides the most basic form of control over event
production. To further refine event production based on the
type of object or thread being monitored, other tables may
be used as described in
<a class="xref" href="performance-schema-pre-filtering.html" title="29.4.3 Event Pre-Filtering">
Section 29.4.3, “Event Pre-Filtering”
</a>
.
</p>
</li>
<li class="listitem">
<p>
Performance Schema tables are the destinations for events
and consume events. The
<a class="link" href="performance-schema-setup-consumers-table.html" title="29.12.2.2 The setup_consumers Table">
<code class="literal">
setup_consumers
</code>
</a>
table lists the
types of consumers to which event information can be sent
and whether they are enabled:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa53028245"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> performance_schema<span class="token punctuation">.</span>setup_consumers<span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> NAME <span class="token punctuation">|</span> ENABLED <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> events_stages_current <span class="token punctuation">|</span> NO <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> events_stages_history <span class="token punctuation">|</span> NO <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> events_stages_history_long <span class="token punctuation">|</span> NO <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> events_statements_cpu <span class="token punctuation">|</span> NO <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> events_statements_current <span class="token punctuation">|</span> YES <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> events_statements_history <span class="token punctuation">|</span> YES <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> events_statements_history_long <span class="token punctuation">|</span> NO <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> events_transactions_current <span class="token punctuation">|</span> YES <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> events_transactions_history <span class="token punctuation">|</span> YES <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> events_transactions_history_long <span class="token punctuation">|</span> NO <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> events_waits_current <span class="token punctuation">|</span> NO <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> events_waits_history <span class="token punctuation">|</span> NO <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> events_waits_history_long <span class="token punctuation">|</span> NO <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> global_instrumentation <span class="token punctuation">|</span> YES <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> thread_instrumentation <span class="token punctuation">|</span> YES <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> statements_digest <span class="token punctuation">|</span> YES <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
</li>
</ul>
</div>
<p>
Filtering can be done at different stages of performance
monitoring:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<b>
Pre-filtering.
</b>
This is done by modifying Performance Schema configuration
so that only certain types of events are collected from
producers, and collected events update only certain
consumers. To do this, enable or disable instruments or
consumers. Pre-filtering is done by the Performance Schema
and has a global effect that applies to all users.
</p>
<p>
Reasons to use pre-filtering:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
To reduce overhead. Performance Schema overhead should
be minimal even with all instruments enabled, but
perhaps you want to reduce it further. Or you do not
care about timing events and want to disable the timing
code to eliminate timing overhead.
</p>
</li>
<li class="listitem">
<p>
To avoid filling the current-events or history tables
with events in which you have no interest. Pre-filtering
leaves more
<span class="quote">
“
<span class="quote">
room
</span>
”
</span>
in these tables for
instances of rows for enabled instrument types. If you
enable only file instruments with pre-filtering, no rows
are collected for nonfile instruments. With
post-filtering, nonfile events are collected, leaving
fewer rows for file events.
</p>
</li>
<li class="listitem">
<p>
To avoid maintaining some kinds of event tables. If you
disable a consumer, the server does not spend time
maintaining destinations for that consumer. For example,
if you do not care about event histories, you can
disable the history table consumers to improve
performance.
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
<b>
Post-filtering.
</b>
This involves the use of
<code class="literal">
WHERE
</code>
clauses
in queries that select information from Performance Schema
tables, to specify which of the available events you want
to see. Post-filtering is performed on a per-user basis
because individual users select which of the available
events are of interest.
</p>
<p>
Reasons to use post-filtering:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
To avoid making decisions for individual users about
which event information is of interest.
</p>
</li>
<li class="listitem">
<p>
To use the Performance Schema to investigate a
performance issue when the restrictions to impose using
pre-filtering are not known in advance.
</p>
</li>
</ul>
</div>
</li>
</ul>
</div>
<p>
The following sections provide more detail about pre-filtering
and provide guidelines for naming instruments or consumers in
filtering operations. For information about writing queries to
retrieve information (post-filtering), see
<a class="xref" href="performance-schema-queries.html" title="29.5 Performance Schema Queries">
Section 29.5, “Performance Schema Queries”
</a>
.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/optimizer-tracing.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h2 class="title">
<a name="optimizer-tracing">
</a>
10.15 Tracing the Optimizer
</h2>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="optimizer-tracing-typical-usage.html">
10.15.1 Typical Usage
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="system-variables-controlling-tracing.html">
10.15.2 System Variables Controlling Tracing
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="traceable-statements.html">
10.15.3 Traceable Statements
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="tuning-trace-purging.html">
10.15.4 Tuning Trace Purging
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="tracing-memory-usage.html">
10.15.5 Tracing Memory Usage
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="privilege-checking.html">
10.15.6 Privilege Checking
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="interaction-with-debug-option.html">
10.15.7 Interaction with the --debug Option
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="optimizer-trace-system-variable.html">
10.15.8 The optimizer_trace System Variable
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="end-markers-in-json-system-variable.html">
10.15.9 The end_markers_in_json System Variable
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="optimizer-features-to-trace.html">
10.15.10 Selecting Optimizer Features to Trace
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="trace-general-structure.html">
10.15.11 Trace General Structure
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="tracing-example.html">
10.15.12 Example
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="displaying-traces.html">
10.15.13 Displaying Traces in Other Applications
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="preventing-use-of-optimizer-trace.html">
10.15.14 Preventing the Use of Optimizer Trace
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="optimizer-trace-testing.html">
10.15.15 Testing Optimizer Trace
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="optimizer-trace-implementation.html">
10.15.16 Optimizer Trace Implementation
</a>
</span>
</dt>
</dl>
</div>
<p>
The MySQL optimizer includes the capability to perform tracing; the
interface is provided by a set of
<code class="literal">
optimizer_trace_xxx
</code>
system variables and the
<a class="link" href="information-schema-optimizer-trace-table.html" title="28.3.19 The INFORMATION_SCHEMA OPTIMIZER_TRACE Table">
<code class="literal">
INFORMATION_SCHEMA.OPTIMIZER_TRACE
</code>
</a>
table.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/server-options.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="server-options">
</a>
7.1.7 Server Command Options
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045280461472">
</a>
<a class="indexterm" name="idm46045280459984">
</a>
<p>
When you start the
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
server, you can
specify program options using any of the methods described in
<a class="xref" href="program-options.html" title="6.2.2 Specifying Program Options">
Section 6.2.2, “Specifying Program Options”
</a>
. The most common methods are to
provide options in an option file or on the command line. However,
in most cases it is desirable to make sure that the server uses
the same options each time it runs. The best way to ensure this is
to list them in an option file. See
<a class="xref" href="option-files.html" title="6.2.2.2 Using Option Files">
Section 6.2.2.2, “Using Option Files”
</a>
. That section also describes option
file format and syntax.
</p>
<p>
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
reads options from the
<code class="literal">
[mysqld]
</code>
and
<code class="literal">
[server]
</code>
groups.
<a class="link" href="mysqld-safe.html" title="6.3.2 mysqld_safe — MySQL Server Startup Script">
<span class="command">
<strong>
mysqld_safe
</strong>
</span>
</a>
reads options from the
<code class="literal">
[mysqld]
</code>
,
<code class="literal">
[server]
</code>
,
<code class="literal">
[mysqld_safe]
</code>
, and
<code class="literal">
[safe_mysqld]
</code>
groups.
<a class="link" href="mysql-server.html" title="6.3.3 mysql.server — MySQL Server Startup Script">
<span class="command">
<strong>
mysql.server
</strong>
</span>
</a>
reads options from the
<code class="literal">
[mysqld]
</code>
and
<code class="literal">
[mysql.server]
</code>
groups.
</p>
<p>
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
accepts many command options. For a
brief summary, execute this command:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa8243806"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal">mysqld <span class="token property">--help</span></code></pre>
</div>
<p>
To see the full list, use this command:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa49327686"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal">mysqld <span class="token property">--verbose</span> <span class="token property">--help</span></code></pre>
</div>
<p>
Some of the items in the list are actually system variables that
can be set at server startup. These can be displayed at runtime
using the
<a class="link" href="show-variables.html" title="15.7.7.41 SHOW VARIABLES Statement">
<code class="literal">
SHOW VARIABLES
</code>
</a>
statement.
Some items displayed by the preceding
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
command do not appear in
<a class="link" href="show-variables.html" title="15.7.7.41 SHOW VARIABLES Statement">
<code class="literal">
SHOW
VARIABLES
</code>
</a>
output; this is because they are options only
and not system variables.
</p>
<p>
The following list shows some of the most common server options.
Additional options are described in other sections:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Options that affect security: See
<a class="xref" href="security-options.html" title="8.1.4 Security-Related mysqld Options and Variables">
Section 8.1.4, “Security-Related mysqld Options and Variables”
</a>
.
</p>
</li>
<li class="listitem">
<p>
SSL-related options: See
<a class="xref" href="connection-options.html#encrypted-connection-options" title="Command Options for Encrypted Connections">
Command Options for Encrypted Connections
</a>
.
</p>
</li>
<li class="listitem">
<p>
Binary log control options: See
<a class="xref" href="binary-log.html" title="7.4.4 The Binary Log">
Section 7.4.4, “The Binary Log”
</a>
.
</p>
</li>
<li class="listitem">
<p>
Replication-related options: See
<a class="xref" href="replication-options.html" title="19.1.6 Replication and Binary Logging Options and Variables">
Section 19.1.6, “Replication and Binary Logging Options and Variables”
</a>
.
</p>
</li>
<li class="listitem">
<p>
Options for loading plugins such as pluggable storage engines:
See
<a class="xref" href="plugin-loading.html" title="7.6.1 Installing and Uninstalling Plugins">
Section 7.6.1, “Installing and Uninstalling Plugins”
</a>
.
</p>
</li>
<li class="listitem">
<p>
Options specific to particular storage engines: See
<a class="xref" href="innodb-parameters.html" title="17.14 InnoDB Startup Options and System Variables">
Section 17.14, “InnoDB Startup Options and System Variables”
</a>
and
<a class="xref" href="myisam-start.html" title="18.2.1 MyISAM Startup Options">
Section 18.2.1, “MyISAM Startup Options”
</a>
.
</p>
</li>
</ul>
</div>
<p>
Some options control the size of buffers or caches. For a given
buffer, the server might need to allocate internal data
structures. These structures typically are allocated from the
total memory allocated to the buffer, and the amount of space
required might be platform dependent. This means that when you
assign a value to an option that controls a buffer size, the
amount of space actually available might differ from the value
assigned. In some cases, the amount might be less than the value
assigned. It is also possible that the server adjusts a value
upward. For example, if you assign a value of 0 to an option for
which the minimal value is 1024, the server sets the value to
1024.
</p>
<p>
Values for buffer sizes, lengths, and stack sizes are given in
bytes unless otherwise specified.
</p>
<p>
Some options take file name values. Unless otherwise specified,
the default file location is the data directory if the value is a
relative path name. To specify the location explicitly, use an
absolute path name. Suppose that the data directory is
<code class="filename">
/var/mysql/data
</code>
. If a file-valued option is
given as a relative path name, it is located under
<code class="filename">
/var/mysql/data
</code>
. If the value is an absolute
path name, its location is as given by the path name.
</p>
<p>
You can also set the values of server system variables at server
startup by using variable names as options. To assign a value to a
server system variable, use an option of the form
<code class="option">
--
<em class="replaceable">
<code>
var_name
</code>
</em>
=
<em class="replaceable">
<code>
value
</code>
</em>
</code>
.
For example,
<a class="link" href="server-system-variables.html#sysvar_sort_buffer_size">
<code class="option">
--sort_buffer_size=384M
</code>
</a>
sets the
<a class="link" href="server-system-variables.html#sysvar_sort_buffer_size">
<code class="literal">
sort_buffer_size
</code>
</a>
variable to a
value of 384MB.
</p>
<p>
When you assign a value to a variable, MySQL might automatically
correct the value to stay within a given range, or adjust the
value to the closest permissible value if only certain values are
permitted.
</p>
<p>
To restrict the maximum value to which a system variable can be
set at runtime with the
<a class="link" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
<code class="literal">
SET
</code>
</a>
statement, specify this maximum by using an option of the form
<code class="option">
--maximum-
<em class="replaceable">
<code>
var_name
</code>
</em>
=
<em class="replaceable">
<code>
value
</code>
</em>
</code>
at server startup.
</p>
<p>
You can change the values of most system variables at runtime with
the
<a class="link" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
<code class="literal">
SET
</code>
</a>
statement. See
<a class="xref" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
Section 15.7.6.1, “SET Syntax for Variable Assignment”
</a>
.
</p>
<p>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
, provides a full
description for all variables, and additional information for
setting them at server startup and runtime. For information on
changing system variables, see
<a class="xref" href="server-configuration.html" title="7.1.1 Configuring the Server">
Section 7.1.1, “Configuring the Server”
</a>
.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a name="option_mysqld_help">
</a>
<a class="link" href="server-options.html#option_mysqld_help">
<code class="option">
--help
</code>
</a>
,
<code class="option">
-?
</code>
</p>
<a class="indexterm" name="idm46045280407616">
</a>
<a class="indexterm" name="idm46045280406128">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for help">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--help
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Display a short help message and exit. Use both the
<a class="link" href="server-options.html#option_mysqld_verbose">
<code class="option">
--verbose
</code>
</a>
and
<a class="link" href="server-options.html#option_mysqld_help">
<code class="option">
--help
</code>
</a>
options to see the full
message.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_allow-suspicious-udfs">
</a>
<a class="link" href="server-options.html#option_mysqld_allow-suspicious-udfs">
<code class="option">
--allow-suspicious-udfs
</code>
</a>
</p>
<a class="indexterm" name="idm46045280394528">
</a>
<a class="indexterm" name="idm46045280393072">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for allow-suspicious-udfs">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--allow-suspicious-udfs[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
This option controls whether loadable functions that have only
an
<code class="literal">
xxx
</code>
symbol for the main function can be
loaded. By default, the option is off and only loadable
functions that have at least one auxiliary symbol can be
loaded; this prevents attempts at loading functions from
shared object files other than those containing legitimate
functions. See
<a class="ulink" href="/doc/extending-mysql/8.4/en/adding-loadable-function.html#loadable-function-security" target="_top">
Loadable Function Security Precautions
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_ansi">
</a>
<a class="link" href="server-options.html#option_mysqld_ansi">
<code class="option">
--ansi
</code>
</a>
</p>
<a class="indexterm" name="idm46045280377120">
</a>
<a class="indexterm" name="idm46045280375632">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for ansi">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--ansi
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Use standard (ANSI) SQL syntax instead of MySQL syntax. For
more precise control over the server SQL mode, use the
<a class="link" href="server-options.html#option_mysqld_sql-mode">
<code class="option">
--sql-mode
</code>
</a>
option instead. See
<a class="xref" href="compatibility.html" title="1.7 MySQL Standards Compliance">
Section 1.7, “MySQL Standards Compliance”
</a>
, and
<a class="xref" href="sql-mode.html" title="7.1.11 Server SQL Modes">
Section 7.1.11, “Server SQL Modes”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a class="indexterm" name="idm46045280365072">
</a>
<a class="indexterm" name="idm46045280363584">
</a>
<a class="link" href="server-system-variables.html#sysvar_basedir">
<code class="option">
--basedir=
<em class="replaceable">
<code>
dir_name
</code>
</em>
</code>
</a>
,
<a class="link" href="server-system-variables.html#sysvar_basedir">
<code class="option">
-b
<em class="replaceable">
<code>
dir_name
</code>
</em>
</code>
</a>
</p>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for basedir">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--basedir=dir_name
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="server-system-variables.html#sysvar_basedir">
basedir
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Directory name
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
parent of mysqld installation directory
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
The path to the MySQL installation directory. This option sets
the
<a class="link" href="server-system-variables.html#sysvar_basedir">
<code class="literal">
basedir
</code>
</a>
system variable.
</p>
<p>
The server executable determines its own full path name at
startup and uses the parent of the directory in which it is
located as the default
<a class="link" href="server-system-variables.html#sysvar_basedir">
<code class="literal">
basedir
</code>
</a>
value. This in turn
enables the server to use that
<a class="link" href="server-system-variables.html#sysvar_basedir">
<code class="literal">
basedir
</code>
</a>
when searching for
server-related information such as the
<code class="filename">
share
</code>
directory containing error
messages.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_chroot">
</a>
<a class="link" href="server-options.html#option_mysqld_chroot">
<code class="option">
--chroot=
<em class="replaceable">
<code>
dir_name
</code>
</em>
</code>
</a>
,
<code class="option">
-r
<em class="replaceable">
<code>
dir_name
</code>
</em>
</code>
</p>
<a class="indexterm" name="idm46045280330400">
</a>
<a class="indexterm" name="idm46045280328912">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for chroot">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--chroot=dir_name
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Directory name
</td>
</tr>
</tbody>
</table>
</div>
<p>
Put the
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
server in a closed
environment during startup by using the
<code class="literal">
chroot()
</code>
system call. This is a recommended
security measure. Use of this option somewhat limits
<a class="link" href="load-data.html" title="15.2.9 LOAD DATA Statement">
<code class="literal">
LOAD DATA
</code>
</a>
and
<a class="link" href="select-into.html" title="15.2.13.1 SELECT ... INTO Statement">
<code class="literal">
SELECT ... INTO
OUTFILE
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_console">
</a>
<a class="link" href="server-options.html#option_mysqld_console">
<code class="option">
--console
</code>
</a>
</p>
<a class="indexterm" name="idm46045280312800">
</a>
<a class="indexterm" name="idm46045280311312">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for console">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--console
</code>
</td>
</tr>
<tr>
<th>
Platform Specific
</th>
<td>
Windows
</td>
</tr>
</tbody>
</table>
</div>
<p>
(Windows only.) Cause the default error log destination to be
the console. This affects log sinks that base their own output
destination on the default destination. See
<a class="xref" href="error-log.html" title="7.4.2 The Error Log">
Section 7.4.2, “The Error Log”
</a>
.
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
does
not close the console window if this option is used.
</p>
<p>
<a class="link" href="server-options.html#option_mysqld_console">
<code class="option">
--console
</code>
</a>
takes precedence over
<a class="link" href="server-options.html#option_mysqld_log-error">
<code class="option">
--log-error
</code>
</a>
if both are given.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_core-file">
</a>
<a class="link" href="server-options.html#option_mysqld_core-file">
<code class="option">
--core-file
</code>
</a>
</p>
<a class="indexterm" name="idm46045280295264">
</a>
<a class="indexterm" name="idm46045280293776">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for core-file">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--core-file
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
When this option is used, write a core file if
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
dies; no arguments are needed (or
accepted). The name and location of the core file is system
dependent. On Linux, a core file named
<code class="filename">
core.
<em class="replaceable">
<code>
pid
</code>
</em>
</code>
is
written to the current working directory of the process, which
for
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
is the data directory.
<em class="replaceable">
<code>
pid
</code>
</em>
represents the process ID of
the server process. On macOS, a core file named
<code class="filename">
core.
<em class="replaceable">
<code>
pid
</code>
</em>
</code>
is
written to the
<code class="filename">
/cores
</code>
directory. On
Solaris, use the
<span class="command">
<strong>
coreadm
</strong>
</span>
command to specify
where to write the core file and how to name it.
</p>
<p>
For some systems, to get a core file you must also specify the
<a class="link" href="mysqld-safe.html#option_mysqld_safe_core-file-size">
<code class="option">
--core-file-size
</code>
</a>
option to
<a class="link" href="mysqld-safe.html" title="6.3.2 mysqld_safe — MySQL Server Startup Script">
<span class="command">
<strong>
mysqld_safe
</strong>
</span>
</a>
. See
<a class="xref" href="mysqld-safe.html" title="6.3.2 mysqld_safe — MySQL Server Startup Script">
Section 6.3.2, “mysqld_safe — MySQL Server Startup Script”
</a>
. On some systems, such as
Solaris, you do not get a core file if you are also using the
<a class="link" href="server-options.html#option_mysqld_user">
<code class="option">
--user
</code>
</a>
option. There might be
additional restrictions or limitations. For example, it might
be necessary to execute
<span class="command">
<strong>
ulimit -c unlimited
</strong>
</span>
before starting the server. Consult your system documentation.
</p>
<p>
The
<a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_in_core_file">
<code class="literal">
innodb_buffer_pool_in_core_file
</code>
</a>
variable can be used to reduce the size of core files on
operating systems that support it. For more information, see
<a class="xref" href="innodb-buffer-pool-in-core-file.html" title="17.8.3.7 Excluding or Including Buffer Pool Pages from Core Files">
Section 17.8.3.7, “Excluding or Including Buffer Pool Pages from Core Files”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_daemonize">
</a>
<a class="link" href="server-options.html#option_mysqld_daemonize">
<code class="option">
--daemonize
</code>
</a>
,
<code class="option">
-D
</code>
</p>
<a class="indexterm" name="idm46045280269200">
</a>
<a class="indexterm" name="idm46045280267712">
</a>
<a class="indexterm" name="idm46045280266224">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for daemonize">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--daemonize[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
This option causes the server to run as a traditional, forking
daemon, permitting it to work with operating systems that use
systemd for process control. For more information, see
<a class="xref" href="using-systemd.html" title="2.5.9 Managing MySQL Server with systemd">
Section 2.5.9, “Managing MySQL Server with systemd”
</a>
.
</p>
<p>
<a class="link" href="server-options.html#option_mysqld_daemonize">
<code class="option">
--daemonize
</code>
</a>
is mutually
exclusive with
<a class="link" href="server-options.html#option_mysqld_initialize">
<code class="option">
--initialize
</code>
</a>
and
<a class="link" href="server-options.html#option_mysqld_initialize-insecure">
<code class="option">
--initialize-insecure
</code>
</a>
.
</p>
<p>
If the server is started using the
<code class="option">
--daemonize
</code>
option and is not connected to a
tty device, a default error logging option of
<code class="option">
--log-error=""
</code>
is used in the absence of an
explicit logging option, to direct error output to the default
log file.
</p>
<p>
<code class="option">
-D
</code>
is a synonym for
<a class="link" href="server-options.html#option_mysqld_daemonize">
<code class="option">
--daemonize
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a class="indexterm" name="idm46045280246144">
</a>
<a class="indexterm" name="idm46045280244656">
</a>
<a class="link" href="server-system-variables.html#sysvar_datadir">
<code class="option">
--datadir=
<em class="replaceable">
<code>
dir_name
</code>
</em>
</code>
</a>
,
<code class="option">
-h
<em class="replaceable">
<code>
dir_name
</code>
</em>
</code>
</p>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for datadir">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--datadir=dir_name
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="server-system-variables.html#sysvar_datadir">
datadir
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Directory name
</td>
</tr>
</tbody>
</table>
</div>
<p>
The path to the MySQL server data directory. This option sets
the
<a class="link" href="server-system-variables.html#sysvar_datadir">
<code class="literal">
datadir
</code>
</a>
system variable.
See the description of that variable.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_debug">
</a>
<a class="link" href="server-options.html#option_mysqld_debug">
<code class="option">
--debug[=
<em class="replaceable">
<code>
debug_options
</code>
</em>
]
</code>
</a>
,
<code class="option">
-# [
<em class="replaceable">
<code>
debug_options
</code>
</em>
]
</code>
</p>
<a class="indexterm" name="idm46045280218336">
</a>
<a class="indexterm" name="idm46045280216848">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for debug">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--debug[=debug_options]
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="server-system-variables.html#sysvar_debug">
debug
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global, Session
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value (Unix)
</th>
<td>
<code class="literal">
d:t:i:o,/tmp/mysqld.trace
</code>
</td>
</tr>
<tr>
<th>
Default Value (Windows)
</th>
<td>
<code class="literal">
d:t:i:O,\mysqld.trace
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
If MySQL is configured with the
<a class="link" href="source-configuration-options.html#option_cmake_with_debug">
<code class="option">
-DWITH_DEBUG=1
</code>
</a>
<span class="command">
<strong>
CMake
</strong>
</span>
option, you can use this option to
get a trace file of what
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
is doing. A
typical
<em class="replaceable">
<code>
debug_options
</code>
</em>
string is
<code class="literal">
d:t:o,
<em class="replaceable">
<code>
file_name
</code>
</em>
</code>
.
The default is
<code class="literal">
d:t:i:o,/tmp/mysqld.trace
</code>
on
Unix and
<code class="literal">
d:t:i:O,\mysqld.trace
</code>
on Windows.
</p>
<p>
Using
<a class="link" href="source-configuration-options.html#option_cmake_with_debug">
<code class="option">
-DWITH_DEBUG=1
</code>
</a>
to
configure MySQL with debugging support enables you to use the
<a class="link" href="server-options.html#option_mysqld_debug">
<code class="option">
--debug="d,parser_debug"
</code>
</a>
option
when you start the server. This causes the Bison parser that
is used to process SQL statements to dump a parser trace to
the server's standard error output. Typically, this output is
written to the error log.
</p>
<p>
This option may be given multiple times. Values that begin
with
<code class="literal">
+
</code>
or
<code class="literal">
-
</code>
are added to
or subtracted from the previous value. For example,
<a class="link" href="server-options.html#option_mysqld_debug">
<code class="option">
--debug=T
</code>
</a>
<a class="link" href="server-options.html#option_mysqld_debug">
<code class="option">
--debug=+P
</code>
</a>
sets the value to
<code class="literal">
P:T
</code>
.
</p>
<p>
For more information, see
<a class="xref" href="dbug-package.html" title="7.9.4 The DBUG Package">
Section 7.9.4, “The DBUG Package”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_debug-sync-timeout">
</a>
<a class="link" href="server-options.html#option_mysqld_debug-sync-timeout">
<code class="option">
--debug-sync-timeout[=
<em class="replaceable">
<code>
N
</code>
</em>
]
</code>
</a>
</p>
<a class="indexterm" name="idm46045280175376">
</a>
<a class="indexterm" name="idm46045280173920">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for debug-sync-timeout">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--debug-sync-timeout[=#]
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
</tbody>
</table>
</div>
<p>
Controls whether the Debug Sync facility for testing and
debugging is enabled. Use of Debug Sync requires that MySQL be
configured with the
<a class="link" href="source-configuration-options.html#option_cmake_with_debug">
<code class="option">
-DWITH_DEBUG=ON
</code>
</a>
<span class="command">
<strong>
CMake
</strong>
</span>
option (see
<a class="xref" href="source-configuration-options.html" title="2.8.7 MySQL Source-Configuration Options">
Section 2.8.7, “MySQL Source-Configuration Options”
</a>
); otherwise,
this option is not available. The option value is a timeout in
seconds. The default value is 0, which disables Debug Sync. To
enable it, specify a value greater than 0; this value also
becomes the default timeout for individual synchronization
points. If the option is given without a value, the timeout is
set to 300 seconds.
</p>
<p>
For a description of the Debug Sync facility and how to use
synchronization points, see
<a class="ulink" href="/doc/internals/en/test-synchronization.html" target="_top">
MySQL
Internals: Test Synchronization
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_default-time-zone">
</a>
<a class="link" href="server-options.html#option_mysqld_default-time-zone">
<code class="option">
--default-time-zone=
<em class="replaceable">
<code>
timezone
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045280157728">
</a>
<a class="indexterm" name="idm46045280156272">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for default-time-zone">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--default-time-zone=name
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
</tbody>
</table>
</div>
<p>
Set the default server time zone. This option sets the global
<a class="link" href="server-system-variables.html#sysvar_time_zone">
<code class="literal">
time_zone
</code>
</a>
system variable. If
this option is not given, the default time zone is the same as
the system time zone (given by the value of the
<a class="link" href="server-system-variables.html#sysvar_system_time_zone">
<code class="literal">
system_time_zone
</code>
</a>
system
variable.
</p>
<p>
The
<a class="link" href="server-system-variables.html#sysvar_system_time_zone">
<code class="literal">
system_time_zone
</code>
</a>
variable
differs from
<a class="link" href="server-system-variables.html#sysvar_time_zone">
<code class="literal">
time_zone
</code>
</a>
.
Although they might have the same value, the latter variable
is used to initialize the time zone for each client that
connects. See
<a class="xref" href="time-zone-support.html" title="7.1.15 MySQL Server Time Zone Support">
Section 7.1.15, “MySQL Server Time Zone Support”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_defaults-extra-file">
</a>
<a class="link" href="server-options.html#option_mysqld_defaults-extra-file">
<code class="option">
--defaults-extra-file=
<em class="replaceable">
<code>
file_name
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045280137904">
</a>
<a class="indexterm" name="idm46045280136448">
</a>
<p>
Read this option file after the global option file but (on
Unix) before the user option file. If the file does not exist
or is otherwise inaccessible, an error occurs. If
<em class="replaceable">
<code>
file_name
</code>
</em>
is not an absolute path
name, it is interpreted relative to the current directory.
This must be the first option on the command line if it is
used.
</p>
<p>
For additional information about this and other option-file
options, see
<a class="xref" href="option-file-options.html" title="6.2.2.3 Command-Line Options that Affect Option-File Handling">
Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_defaults-file">
</a>
<a class="link" href="server-options.html#option_mysqld_defaults-file">
<code class="option">
--defaults-file=
<em class="replaceable">
<code>
file_name
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045280130016">
</a>
<a class="indexterm" name="idm46045280128528">
</a>
<p>
Read only the given option file. If the file does not exist or
is otherwise inaccessible, an error occurs. If
<em class="replaceable">
<code>
file_name
</code>
</em>
is not an absolute path
name, it is interpreted relative to the current directory.
</p>
<p>
Exception: Even with
<a class="link" href="server-options.html#option_mysqld_defaults-file">
<code class="option">
--defaults-file
</code>
</a>
,
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
reads
<code class="filename">
mysqld-auto.cnf
</code>
.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
This must be the first option on the command line if it is
used, except that if the server is started with the
<a class="link" href="server-options.html#option_mysqld_defaults-file">
<code class="option">
--defaults-file
</code>
</a>
and
<a class="link" href="server-options.html#option_mysqld_install">
<code class="option">
--install
</code>
</a>
(or
<a class="link" href="server-options.html#option_mysqld_install-manual">
<code class="option">
--install-manual
</code>
</a>
) options,
<a class="link" href="server-options.html#option_mysqld_install">
<code class="option">
--install
</code>
</a>
(or
<a class="link" href="server-options.html#option_mysqld_install-manual">
<code class="option">
--install-manual
</code>
</a>
) must be
first.
</p>
</div>
<p>
For additional information about this and other option-file
options, see
<a class="xref" href="option-file-options.html" title="6.2.2.3 Command-Line Options that Affect Option-File Handling">
Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_defaults-group-suffix">
</a>
<a class="link" href="server-options.html#option_mysqld_defaults-group-suffix">
<code class="option">
--defaults-group-suffix=
<em class="replaceable">
<code>
str
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045280113216">
</a>
<a class="indexterm" name="idm46045280111712">
</a>
<p>
Read not only the usual option groups, but also groups with
the usual names and a suffix of
<em class="replaceable">
<code>
str
</code>
</em>
. For example,
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
normally reads the
<code class="literal">
[mysqld]
</code>
group. If this option is given as
<a class="link" href="server-options.html#option_mysqld_defaults-group-suffix">
<code class="option">
--defaults-group-suffix=_other
</code>
</a>
,
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
also reads the
<code class="literal">
[mysqld_other]
</code>
group.
</p>
<p>
For additional information about this and other option-file
options, see
<a class="xref" href="option-file-options.html" title="6.2.2.3 Command-Line Options that Affect Option-File Handling">
Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_early-plugin-load">
</a>
<a class="link" href="server-options.html#option_mysqld_early-plugin-load">
<code class="option">
--early-plugin-load=
<em class="replaceable">
<code>
plugin_list
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045280100576">
</a>
<a class="indexterm" name="idm46045280099120">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for early-plugin-load">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--early-plugin-load=plugin_list
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
empty string
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
This option tells the server which plugins to load before
loading mandatory built-in plugins and before storage engine
initialization. Early loading is supported only for plugins
compiled with
<code class="option">
PLUGIN_OPT_ALLOW_EARLY
</code>
. If
multiple
<a class="link" href="server-options.html#option_mysqld_early-plugin-load">
<code class="option">
--early-plugin-load
</code>
</a>
options are given, only the last one applies.
</p>
<p>
The option value is a semicolon-separated list of
<em class="replaceable">
<code>
plugin_library
</code>
</em>
and
<em class="replaceable">
<code>
name
</code>
</em>
<code class="literal">
=
</code>
<em class="replaceable">
<code>
plugin_library
</code>
</em>
values. Each
<em class="replaceable">
<code>
plugin_library
</code>
</em>
is the
name of a library file that contains plugin code, and each
<em class="replaceable">
<code>
name
</code>
</em>
is the name of a plugin to
load. If a plugin library is named without any preceding
plugin name, the server loads all plugins in the library. With
a preceding plugin name, the server loads only the named
plugin from the library. The server looks for plugin library
files in the directory named by the
<a class="link" href="server-system-variables.html#sysvar_plugin_dir">
<code class="literal">
plugin_dir
</code>
</a>
system variable.
</p>
<p>
For example, if plugins named
<code class="literal">
myplug1
</code>
and
<code class="literal">
myplug2
</code>
are contained in the plugin library
files
<code class="filename">
myplug1.so
</code>
and
<code class="filename">
myplug2.so
</code>
, use this option to perform an
early plugin load:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa28816499"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal">mysqld <span class="token constant">--early-plugin-load</span>=<span class="token atrule">"myplug1=myplug1.so;myplug2=myplug2.so"</span></code></pre>
</div>
<p>
Quotes surround the argument value because otherwise some
command interpreters interpret semicolon
(
<code class="literal">
;
</code>
) as a special character. (For example,
Unix shells treat it as a command terminator.)
</p>
<p>
Each named plugin is loaded early for a single invocation of
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
only. After a restart, the plugin is
not loaded early unless
<a class="link" href="server-options.html#option_mysqld_early-plugin-load">
<code class="option">
--early-plugin-load
</code>
</a>
is used
again.
</p>
<p>
If the server is started using
<a class="link" href="server-options.html#option_mysqld_initialize">
<code class="option">
--initialize
</code>
</a>
or
<a class="link" href="server-options.html#option_mysqld_initialize-insecure">
<code class="option">
--initialize-insecure
</code>
</a>
, plugins
specified by
<a class="link" href="server-options.html#option_mysqld_early-plugin-load">
<code class="option">
--early-plugin-load
</code>
</a>
are not
loaded.
</p>
<p>
If the server is run with
<a class="link" href="server-options.html#option_mysqld_help">
<code class="option">
--help
</code>
</a>
, plugins specified by
<a class="link" href="server-options.html#option_mysqld_early-plugin-load">
<code class="option">
--early-plugin-load
</code>
</a>
are loaded
but not initialized. This behavior ensures that plugin options
are displayed in the help message.
</p>
<p>
<code class="literal">
InnoDB
</code>
tablespace encryption relies on the
MySQL Keyring for encryption key management, and the keyring
plugin to be used must be loaded prior to storage engine
initialization to facilitate
<code class="literal">
InnoDB
</code>
recovery for encrypted tables. For example, administrators who
want the
<code class="literal">
keyring_okv
</code>
plugin loaded at
startup should use
<a class="link" href="server-options.html#option_mysqld_early-plugin-load">
<code class="option">
--early-plugin-load
</code>
</a>
with the
appropriate option value (such as
<code class="literal">
keyring_okv.so
</code>
on Unix and Unix-like
systems or
<code class="literal">
keyring_okv.dll
</code>
on Windows).
</p>
<p>
For information about
<code class="literal">
InnoDB
</code>
tablespace
encryption, see
<a class="xref" href="innodb-data-encryption.html" title="17.13 InnoDB Data-at-Rest Encryption">
Section 17.13, “InnoDB Data-at-Rest Encryption”
</a>
. For
general information about plugin loading, see
<a class="xref" href="plugin-loading.html" title="7.6.1 Installing and Uninstalling Plugins">
Section 7.6.1, “Installing and Uninstalling Plugins”
</a>
.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
For MySQL Keyring, this option is used only when the
keystore is managed with a keyring plugin. If keystore
management uses a keyring component rather than a plugin,
specify component loading using a manifest file; see
<a class="xref" href="keyring-component-installation.html" title="8.4.4.2 Keyring Component Installation">
Section 8.4.4.2, “Keyring Component Installation”
</a>
.
</p>
</div>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_exit-info">
</a>
<a class="link" href="server-options.html#option_mysqld_exit-info">
<code class="option">
--exit-info[=
<em class="replaceable">
<code>
flags
</code>
</em>
]
</code>
</a>
,
<code class="option">
-T [
<em class="replaceable">
<code>
flags
</code>
</em>
]
</code>
</p>
<a class="indexterm" name="idm46045280052736">
</a>
<a class="indexterm" name="idm46045280051248">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for exit-info">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--exit-info[=flags]
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
</tbody>
</table>
</div>
<p>
This is a bitmask of different flags that you can use for
debugging the
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
server. Do not use
this option unless you know
<span class="emphasis">
<em>
exactly
</em>
</span>
what
it does!
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_external-locking">
</a>
<a class="link" href="server-options.html#option_mysqld_external-locking">
<code class="option">
--external-locking
</code>
</a>
</p>
<a class="indexterm" name="idm46045280037712">
</a>
<a class="indexterm" name="idm46045280036640">
</a>
<a class="indexterm" name="idm46045280035152">
</a>
<a class="indexterm" name="idm46045280033664">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for external-locking">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--external-locking[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Enable external locking (system locking), which is disabled by
default. If you use this option on a system on which
<code class="literal">
lockd
</code>
does not fully work (such as Linux),
it is easy for
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
to deadlock.
</p>
<p>
To disable external locking explicitly, use
<code class="option">
--skip-external-locking
</code>
.
</p>
<p>
External locking affects only
<a class="link" href="myisam-storage-engine.html" title="18.2 The MyISAM Storage Engine">
<code class="literal">
MyISAM
</code>
</a>
table access. For more
information, including conditions under which it can and
cannot be used, see
<a class="xref" href="external-locking.html" title="10.11.5 External Locking">
Section 10.11.5, “External Locking”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_flush">
</a>
<a class="link" href="server-options.html#option_mysqld_flush">
<code class="option">
--flush
</code>
</a>
</p>
<a class="indexterm" name="idm46045280013936">
</a>
<a class="indexterm" name="idm46045280012448">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for flush">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--flush[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="server-system-variables.html#sysvar_flush">
flush
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Flush (synchronize) all changes to disk after each SQL
statement. Normally, MySQL does a write of all changes to disk
only after each SQL statement and lets the operating system
handle the synchronizing to disk. See
<a class="xref" href="crashing.html" title="B.3.3.3 What to Do If MySQL Keeps Crashing">
Section B.3.3.3, “What to Do If MySQL Keeps Crashing”
</a>
.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
If
<a class="link" href="server-options.html#option_mysqld_flush">
<code class="option">
--flush
</code>
</a>
is specified, the
value of
<a class="link" href="server-system-variables.html#sysvar_flush_time">
<code class="literal">
flush_time
</code>
</a>
does
not matter and changes to
<a class="link" href="server-system-variables.html#sysvar_flush_time">
<code class="literal">
flush_time
</code>
</a>
have no effect
on flush behavior.
</p>
</div>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_gdb">
</a>
<a class="link" href="server-options.html#option_mysqld_gdb">
<code class="option">
--gdb
</code>
</a>
</p>
<a class="indexterm" name="idm46045279982880">
</a>
<a class="indexterm" name="idm46045279981392">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for gdb">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--gdb[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Install an interrupt handler for
<code class="literal">
SIGINT
</code>
(needed to stop
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
with
<code class="literal">
^C
</code>
to set breakpoints) and disable stack
tracing and core file handling. See
<a class="xref" href="using-gdb-on-mysqld.html" title="7.9.1.4 Debugging mysqld under gdb">
Section 7.9.1.4, “Debugging mysqld under gdb”
</a>
.
</p>
<p>
On Windows, this option also suppresses the forking that is
used to implement the
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
statement: Forking enables one process to act as a monitor to
the other, which acts as the server. However, forking makes
determining the server process to attach to for debugging more
difficult, so starting the server with
<a class="link" href="server-options.html#option_mysqld_gdb">
<code class="option">
--gdb
</code>
</a>
suppresses forking. For a
server started with this option,
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
simply exits and does
not restart.
</p>
<p>
In non-debug settings,
<a class="link" href="server-options.html#option_mysqld_no-monitor">
<code class="option">
--no-monitor
</code>
</a>
may be used to
suppress forking the monitor process.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_initialize">
</a>
<a class="link" href="server-options.html#option_mysqld_initialize">
<code class="option">
--initialize
</code>
</a>
,
<code class="option">
-I
</code>
</p>
<a class="indexterm" name="idm46045279957664">
</a>
<a class="indexterm" name="idm46045279956176">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for initialize">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--initialize[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
This option is used to initialize a MySQL installation by
creating the data directory and populating the tables in the
<code class="literal">
mysql
</code>
system schema. For more information,
see
<a class="xref" href="data-directory-initialization.html" title="2.9.1 Initializing the Data Directory">
Section 2.9.1, “Initializing the Data Directory”
</a>
.
</p>
<p>
This option limits the effects of, or is not compatible with,
a number of other startup options for the MySQL server. Some
of the most common issues of this sort are noted here:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
We strongly recommend, when initializing the data
directory with
<code class="option">
--initialize
</code>
, that you
specify no additional options other than
<a class="link" href="server-system-variables.html#sysvar_datadir">
<code class="option">
--datadir
</code>
</a>
, other options
used for setting directory locations such as
<a class="link" href="server-system-variables.html#sysvar_basedir">
<code class="option">
--basedir
</code>
</a>
, and possibly
<a class="link" href="server-options.html#option_mysqld_user">
<code class="option">
--user
</code>
</a>
, if required.
Options for the running MySQL server can be specified when
starting it once initialization has been completed and
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
has shut down. This also applies
when using
<a class="link" href="server-options.html#option_mysqld_initialize-insecure">
<code class="option">
--initialize-insecure
</code>
</a>
instead of
<code class="option">
--initialize
</code>
.
</p>
</li>
<li class="listitem">
<p>
When the server is started with
<code class="option">
--initialize
</code>
, some functionality is
unavailable that limits the statements permitted in any
file named by the
<a class="link" href="server-system-variables.html#sysvar_init_file">
<code class="literal">
init_file
</code>
</a>
system
variable. For more information, see the description of
that variable. In addition, the
<a class="link" href="server-system-variables.html#sysvar_disabled_storage_engines">
<code class="literal">
disabled_storage_engines
</code>
</a>
system variable has no effect.
</p>
</li>
<li class="listitem">
<p>
The
<a class="link" href="mysql-cluster-options-variables.html#option_mysqld_ndbcluster">
<code class="option">
--ndbcluster
</code>
</a>
option is
ignored when used together with
<code class="option">
--initialize
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="option">
--initialize
</code>
is mutually exclusive with
<a class="ulink" href="/doc/refman/5.7/en/server-options.html#option_mysqld_bootstrap" target="_top">
<code class="option">
--bootstrap
</code>
</a>
and
<a class="link" href="server-options.html#option_mysqld_daemonize">
<code class="option">
--daemonize
</code>
</a>
.
</p>
</li>
</ul>
</div>
<p>
The items in the preceding list also apply when initializing
the server using the
<a class="link" href="server-options.html#option_mysqld_initialize-insecure">
<code class="option">
--initialize-insecure
</code>
</a>
option.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_initialize-insecure">
</a>
<a class="link" href="server-options.html#option_mysqld_initialize-insecure">
<code class="option">
--initialize-insecure
</code>
</a>
</p>
<a class="indexterm" name="idm46045279921200">
</a>
<a class="indexterm" name="idm46045279919744">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for initialize-insecure">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--initialize-insecure[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
This option is used to initialize a MySQL installation by
creating the data directory and populating the tables in the
<code class="literal">
mysql
</code>
system schema. This option implies
<a class="link" href="server-options.html#option_mysqld_initialize">
<code class="option">
--initialize
</code>
</a>
, and the same
restrictions and limitations apply; for more information, see
the description of that option, and
<a class="xref" href="data-directory-initialization.html" title="2.9.1 Initializing the Data Directory">
Section 2.9.1, “Initializing the Data Directory”
</a>
.
</p>
<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Warning
</div>
<p>
This option creates a MySQL
<code class="literal">
root
</code>
user
with an empty password, which is insecure. For this reason,
do not use it in production without setting this password
manually. See
<a class="xref" href="data-directory-initialization.html#data-directory-initialization-password-assignment" title="Post-Initialization root Password Assignment">
Post-Initialization root Password Assignment
</a>
,
for information about how to do this.
</p>
</div>
</li>
<li class="listitem">
<p>
<code class="option">
--innodb-
<em class="replaceable">
<code>
xxx
</code>
</em>
</code>
</p>
<p>
Set an option for the
<code class="literal">
InnoDB
</code>
storage
engine. The
<code class="literal">
InnoDB
</code>
options are listed in
<a class="xref" href="innodb-parameters.html" title="17.14 InnoDB Startup Options and System Variables">
Section 17.14, “InnoDB Startup Options and System Variables”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_install">
</a>
<a class="link" href="server-options.html#option_mysqld_install">
<code class="option">
--install
[
<em class="replaceable">
<code>
service_name
</code>
</em>
]
</code>
</a>
</p>
<a class="indexterm" name="idm46045279896048">
</a>
<a class="indexterm" name="idm46045279894560">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for install">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--install [service_name]
</code>
</td>
</tr>
<tr>
<th>
Platform Specific
</th>
<td>
Windows
</td>
</tr>
</tbody>
</table>
</div>
<p>
(Windows only) Install the server as a Windows service that
starts automatically during Windows startup. The default
service name is
<code class="literal">
MySQL
</code>
if no
<em class="replaceable">
<code>
service_name
</code>
</em>
value is given. For
more information, see
<a class="xref" href="windows-start-service.html" title="2.3.3.8 Starting MySQL as a Windows Service">
Section 2.3.3.8, “Starting MySQL as a Windows Service”
</a>
.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
If the server is started with the
<a class="link" href="server-options.html#option_mysqld_defaults-file">
<code class="option">
--defaults-file
</code>
</a>
and
<a class="link" href="server-options.html#option_mysqld_install">
<code class="option">
--install
</code>
</a>
options,
<a class="link" href="server-options.html#option_mysqld_install">
<code class="option">
--install
</code>
</a>
must be first.
</p>
</div>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_install-manual">
</a>
<a class="link" href="server-options.html#option_mysqld_install-manual">
<code class="option">
--install-manual
[
<em class="replaceable">
<code>
service_name
</code>
</em>
]
</code>
</a>
</p>
<a class="indexterm" name="idm46045279876672">
</a>
<a class="indexterm" name="idm46045279875184">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for install-manual">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--install-manual [service_name]
</code>
</td>
</tr>
<tr>
<th>
Platform Specific
</th>
<td>
Windows
</td>
</tr>
</tbody>
</table>
</div>
<p>
(Windows only) Install the server as a Windows service that
must be started manually. It does not start automatically
during Windows startup. The default service name is
<code class="literal">
MySQL
</code>
if no
<em class="replaceable">
<code>
service_name
</code>
</em>
value is given. For
more information, see
<a class="xref" href="windows-start-service.html" title="2.3.3.8 Starting MySQL as a Windows Service">
Section 2.3.3.8, “Starting MySQL as a Windows Service”
</a>
.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
If the server is started with the
<a class="link" href="option-file-options.html#option_general_defaults-file">
<code class="option">
--defaults-file
</code>
</a>
and
<a class="link" href="server-options.html#option_mysqld_install-manual">
<code class="option">
--install-manual
</code>
</a>
options,
<a class="link" href="server-options.html#option_mysqld_install-manual">
<code class="option">
--install-manual
</code>
</a>
must be
first.
</p>
</div>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_large-pages">
</a>
<a class="link" href="server-options.html#option_mysqld_large-pages">
<code class="option">
--large-pages
</code>
</a>
</p>
<a class="indexterm" name="idm46045279857552">
</a>
<a class="indexterm" name="idm46045279856064">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for large-pages">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--large-pages[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="server-system-variables.html#sysvar_large_pages">
large_pages
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Platform Specific
</th>
<td>
Linux
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Some hardware/operating system architectures support memory
pages greater than the default (usually 4KB). The actual
implementation of this support depends on the underlying
hardware and operating system. Applications that perform a lot
of memory accesses may obtain performance improvements by
using large pages due to reduced Translation Lookaside Buffer
(TLB) misses.
</p>
<p>
MySQL supports the Linux implementation of large page support
(which is called HugeTLB in Linux). See
<a class="xref" href="large-page-support.html" title="10.12.3.3 Enabling Large Page Support">
Section 10.12.3.3, “Enabling Large Page Support”
</a>
. For Solaris support of
large pages, see the description of the
<a class="link" href="server-options.html#option_mysqld_super-large-pages">
<code class="option">
--super-large-pages
</code>
</a>
option.
</p>
<p>
<a class="link" href="server-options.html#option_mysqld_large-pages">
<code class="option">
--large-pages
</code>
</a>
is disabled by
default.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_lc-messages">
</a>
<a class="link" href="server-options.html#option_mysqld_lc-messages">
<code class="option">
--lc-messages=
<em class="replaceable">
<code>
locale_name
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045279824736">
</a>
<a class="indexterm" name="idm46045279823248">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for lc-messages">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--lc-messages=name
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="server-system-variables.html#sysvar_lc_messages">
lc_messages
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global, Session
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
en_US
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
The locale to use for error messages. The default is
<code class="literal">
en_US
</code>
. The server converts the argument to
a language name and combines it with the value of
<a class="link" href="server-options.html#option_mysqld_lc-messages-dir">
<code class="option">
--lc-messages-dir
</code>
</a>
to produce
the location for the error message file. See
<a class="xref" href="error-message-language.html" title="12.12 Setting the Error Message Language">
Section 12.12, “Setting the Error Message Language”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_lc-messages-dir">
</a>
<a class="link" href="server-options.html#option_mysqld_lc-messages-dir">
<code class="option">
--lc-messages-dir=
<em class="replaceable">
<code>
dir_name
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045279796016">
</a>
<a class="indexterm" name="idm46045279794528">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for lc-messages-dir">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--lc-messages-dir=dir_name
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="server-system-variables.html#sysvar_lc_messages_dir">
lc_messages_dir
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Directory name
</td>
</tr>
</tbody>
</table>
</div>
<p>
The directory where error messages are located. The server
uses the value together with the value of
<a class="link" href="server-options.html#option_mysqld_lc-messages">
<code class="option">
--lc-messages
</code>
</a>
to produce the
location for the error message file. See
<a class="xref" href="error-message-language.html" title="12.12 Setting the Error Message Language">
Section 12.12, “Setting the Error Message Language”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_local-service">
</a>
<a class="link" href="server-options.html#option_mysqld_local-service">
<code class="option">
--local-service
</code>
</a>
</p>
<a class="indexterm" name="idm46045279770960">
</a>
<a class="indexterm" name="idm46045279769472">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for local-service">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--local-service
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
(Windows only) A
<code class="option">
--local-service
</code>
option
following the service name causes the server to run using the
<code class="literal">
LocalService
</code>
Windows account that has
limited system privileges. If both
<a class="link" href="option-file-options.html#option_general_defaults-file">
<code class="option">
--defaults-file
</code>
</a>
and
<code class="option">
--local-service
</code>
are given following the
service name, they can be in any order. See
<a class="xref" href="windows-start-service.html" title="2.3.3.8 Starting MySQL as a Windows Service">
Section 2.3.3.8, “Starting MySQL as a Windows Service”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_log-error">
</a>
<a class="link" href="server-options.html#option_mysqld_log-error">
<code class="option">
--log-error[=
<em class="replaceable">
<code>
file_name
</code>
</em>
]
</code>
</a>
</p>
<a class="indexterm" name="idm46045279756032">
</a>
<a class="indexterm" name="idm46045279754544">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for log-error">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--log-error[=file_name]
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="server-system-variables.html#sysvar_log_error">
log_error
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
File name
</td>
</tr>
</tbody>
</table>
</div>
<p>
Set the default error log destination to the named file. This
affects log sinks that base their own output destination on
the default destination. See
<a class="xref" href="error-log.html" title="7.4.2 The Error Log">
Section 7.4.2, “The Error Log”
</a>
.
</p>
<p>
If the option names no file, the default error log destination
on Unix and Unix-like systems is a file named
<code class="filename">
<em class="replaceable">
<code>
host_name
</code>
</em>
.err
</code>
in the data directory. The default destination on Windows is
the same, unless the
<a class="link" href="server-system-variables.html#sysvar_pid_file">
<code class="option">
--pid-file
</code>
</a>
option is specified. In that case, the file name is the PID
file base name with a suffix of
<code class="filename">
.err
</code>
in
the data directory.
</p>
<p>
If the option names a file, the default destination is that
file (with an
<code class="filename">
.err
</code>
suffix added if the
name has no suffix), located under the data directory unless
an absolute path name is given to specify a different
location.
</p>
<p>
If error log output cannot be redirected to the error log
file, an error occurs and startup fails.
</p>
<p>
On Windows,
<a class="link" href="server-options.html#option_mysqld_console">
<code class="option">
--console
</code>
</a>
takes
precedence over
<a class="link" href="server-options.html#option_mysqld_log-error">
<code class="option">
--log-error
</code>
</a>
if
both are given. In this case, the default error log
destination is the console rather than a file.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_log-isam">
</a>
<a class="link" href="server-options.html#option_mysqld_log-isam">
<code class="option">
--log-isam[=
<em class="replaceable">
<code>
file_name
</code>
</em>
]
</code>
</a>
</p>
<a class="indexterm" name="idm46045279723760">
</a>
<a class="indexterm" name="idm46045279722272">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for log-isam">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--log-isam[=file_name]
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
File name
</td>
</tr>
</tbody>
</table>
</div>
<p>
Log all
<code class="literal">
MyISAM
</code>
changes to this file (used
only when debugging
<code class="literal">
MyISAM
</code>
).
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_log-raw">
</a>
<a class="link" href="server-options.html#option_mysqld_log-raw">
<code class="option">
--log-raw
</code>
</a>
</p>
<a class="indexterm" name="idm46045279709200">
</a>
<a class="indexterm" name="idm46045279707712">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for log-raw">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--log-raw[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="server-system-variables.html#sysvar_log_raw">
log_raw
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Passwords in certain statements written to the general query
log, slow query log, and binary log are rewritten by the
server not to occur literally in plain text. Password
rewriting can be suppressed for the general query log by
starting the server with the
<a class="link" href="server-options.html#option_mysqld_log-raw">
<code class="option">
--log-raw
</code>
</a>
option. This option
may be useful for diagnostic purposes, to see the exact text
of statements as received by the server, but for security
reasons is not recommended for production use.
</p>
<p>
If a query rewrite plugin is installed, the
<a class="link" href="server-options.html#option_mysqld_log-raw">
<code class="option">
--log-raw
</code>
</a>
option affects
statement logging as follows:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
Without
<a class="link" href="server-options.html#option_mysqld_log-raw">
<code class="option">
--log-raw
</code>
</a>
, the
server logs the statement returned by the query rewrite
plugin. This may differ from the statement as received.
</p>
</li>
<li class="listitem">
<p>
With
<a class="link" href="server-options.html#option_mysqld_log-raw">
<code class="option">
--log-raw
</code>
</a>
, the server
logs the original statement as received.
</p>
</li>
</ul>
</div>
<p>
For more information, see
<a class="xref" href="password-logging.html" title="8.1.2.3 Passwords and Logging">
Section 8.1.2.3, “Passwords and Logging”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_log-short-format">
</a>
<a class="link" href="server-options.html#option_mysqld_log-short-format">
<code class="option">
--log-short-format
</code>
</a>
</p>
<a class="indexterm" name="idm46045279675024">
</a>
<a class="indexterm" name="idm46045279673536">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for log-short-format">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--log-short-format[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Log less information to the slow query log, if it has been
activated.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_log-tc">
</a>
<a class="link" href="server-options.html#option_mysqld_log-tc">
<code class="option">
--log-tc=
<em class="replaceable">
<code>
file_name
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045279659248">
</a>
<a class="indexterm" name="idm46045279657760">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for log-tc">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--log-tc=file_name
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
File name
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
tc.log
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
The name of the memory-mapped transaction coordinator log file
(for XA transactions that affect multiple storage engines when
the binary log is disabled). The default name is
<code class="filename">
tc.log
</code>
. The file is created under the
data directory if not given as a full path name. This option
is unused.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_log-tc-size">
</a>
<a class="link" href="server-options.html#option_mysqld_log-tc-size">
<code class="option">
--log-tc-size=
<em class="replaceable">
<code>
size
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045279642352">
</a>
<a class="indexterm" name="idm46045279640864">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for log-tc-size">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--log-tc-size=#
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
6 * page size
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
6 * page size
</code>
</td>
</tr>
<tr>
<th>
Maximum Value (64-bit platforms)
</th>
<td>
<code class="literal">
18446744073709551615
</code>
</td>
</tr>
<tr>
<th>
Maximum Value (32-bit platforms)
</th>
<td>
<code class="literal">
4294967295
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
The size in bytes of the memory-mapped transaction coordinator
log. The default and minimum values are 6 times the page size,
and the value must be a multiple of the page size.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_memlock">
</a>
<a class="link" href="server-options.html#option_mysqld_memlock">
<code class="option">
--memlock
</code>
</a>
</p>
<a class="indexterm" name="idm46045279619280">
</a>
<a class="indexterm" name="idm46045279617792">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for memlock">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--memlock[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Lock the
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
process in memory. This
option might help if you have a problem where the operating
system is causing
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
to swap to disk.
</p>
<p>
<a class="link" href="server-options.html#option_mysqld_memlock">
<code class="option">
--memlock
</code>
</a>
works on systems that
support the
<code class="literal">
mlockall()
</code>
system call; this
includes Solaris, most Linux distributions that use a 2.4 or
higher kernel, and perhaps other Unix systems. On Linux
systems, you can tell whether or not
<code class="literal">
mlockall()
</code>
(and thus this option) is
supported by checking to see whether or not it is defined in
the system
<code class="filename">
mman.h
</code>
file, like this:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa63678046"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token prompt">$> </span><span class="token command">grep</span> mlockall /usr/include/sys/mman<span class="token punctuation">.</span>h</code></pre>
</div>
<p>
If
<code class="literal">
mlockall()
</code>
is supported, you should see
in the output of the previous command something like the
following:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa87590147"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal">extern int mlockall <span class="token punctuation">(</span>int __flags<span class="token punctuation">)</span> __THROW<span class="token punctuation">;</span></code></pre>
</div>
<div class="important" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Important
</div>
<p>
Use of this option may require you to run the server as
<code class="literal">
root
</code>
, which, for reasons of security, is
normally not a good idea. See
<a class="xref" href="changing-mysql-user.html" title="8.1.5 How to Run MySQL as a Normal User">
Section 8.1.5, “How to Run MySQL as a Normal User”
</a>
.
</p>
<p>
On Linux and perhaps other systems, you can avoid the need
to run the server as
<code class="literal">
root
</code>
by changing the
<code class="filename">
limits.conf
</code>
file. See the notes
regarding the memlock limit in
<a class="xref" href="large-page-support.html" title="10.12.3.3 Enabling Large Page Support">
Section 10.12.3.3, “Enabling Large Page Support”
</a>
.
</p>
<p>
You must not use this option on a system that does not
support the
<code class="literal">
mlockall()
</code>
system call; if
you do so,
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
is very likely to exit
as soon as you try to start it.
</p>
</div>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_myisam-block-size">
</a>
<a class="link" href="server-options.html#option_mysqld_myisam-block-size">
<code class="option">
--myisam-block-size=
<em class="replaceable">
<code>
N
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045279585568">
</a>
<a class="indexterm" name="idm46045279584112">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for myisam-block-size">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--myisam-block-size=#
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
1024
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
1024
</code>
</td>
</tr>
<tr>
<th>
Maximum Value
</th>
<td>
<code class="literal">
16384
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
The block size to be used for
<code class="literal">
MyISAM
</code>
index
pages.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_mysql-native-password">
</a>
<a class="link" href="server-options.html#option_mysqld_mysql-native-password">
<code class="option">
--mysql-native-password
</code>
</a>
</p>
<a class="indexterm" name="idm46045279564272">
</a>
<a class="indexterm" name="idm46045279562816">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for mysql-native-password">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--mysql-native-password={OFF|ON}
</code>
</td>
</tr>
<tr>
<th>
Deprecated
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Enable the
<code class="literal">
mysql_native_password
</code>
authentication plugin, which is disabled by default in MySQL
8.4.
</p>
<p>
For more information, see
<a class="xref" href="native-pluggable-authentication.html" title="8.4.1.1 Native Pluggable Authentication">
Section 8.4.1.1, “Native Pluggable Authentication”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_no-defaults">
</a>
<a class="link" href="server-options.html#option_mysqld_no-defaults">
<code class="option">
--no-defaults
</code>
</a>
</p>
<a class="indexterm" name="idm46045279544688">
</a>
<a class="indexterm" name="idm46045279543200">
</a>
<p>
Do not read any option files. If program startup fails due to
reading unknown options from an option file,
<a class="link" href="server-options.html#option_mysqld_no-defaults">
<code class="option">
--no-defaults
</code>
</a>
can be used to
prevent them from being read. This must be the first option on
the command line if it is used.
</p>
<p>
For additional information about this and other option-file
options, see
<a class="xref" href="option-file-options.html" title="6.2.2.3 Command-Line Options that Affect Option-File Handling">
Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_no-monitor">
</a>
<a class="link" href="server-options.html#option_mysqld_no-monitor">
<code class="option">
--no-monitor
</code>
</a>
</p>
<a class="indexterm" name="idm46045279536688">
</a>
<a class="indexterm" name="idm46045279535200">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for no-monitor">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--no-monitor[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
Platform Specific
</th>
<td>
Windows
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
(Windows only). This option suppresses the forking that is
used to implement the
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
statement: Forking enables one process to act as a monitor to
the other, which acts as the server. For a server started with
this option,
<a class="link" href="restart.html" title="15.7.8.8 RESTART Statement">
<code class="literal">
RESTART
</code>
</a>
simply
exits and does not restart.
</p>
</li>
<li class="listitem">
<p>
<code class="option">
--performance-schema-xxx
</code>
</p>
<p>
Configure a Performance Schema option. For details, see
<a class="xref" href="performance-schema-options.html" title="29.14 Performance Schema Command Options">
Section 29.14, “Performance Schema Command Options”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_plugin-load">
</a>
<a class="link" href="server-options.html#option_mysqld_plugin-load">
<code class="option">
--plugin-load=
<em class="replaceable">
<code>
plugin_list
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045279513536">
</a>
<a class="indexterm" name="idm46045279512048">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for plugin-load">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--plugin-load=plugin_list
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
</tbody>
</table>
</div>
<p>
This option tells the server to load the named plugins at
startup. If multiple
<a class="link" href="server-options.html#option_mysqld_plugin-load">
<code class="option">
--plugin-load
</code>
</a>
options are
given, only the last one applies. Additional plugins to load
may be specified using
<a class="link" href="server-options.html#option_mysqld_plugin-load-add">
<code class="option">
--plugin-load-add
</code>
</a>
options.
</p>
<p>
The option value is a semicolon-separated list of
<em class="replaceable">
<code>
plugin_library
</code>
</em>
and
<em class="replaceable">
<code>
name
</code>
</em>
<code class="literal">
=
</code>
<em class="replaceable">
<code>
plugin_library
</code>
</em>
values. Each
<em class="replaceable">
<code>
plugin_library
</code>
</em>
is the
name of a library file that contains plugin code, and each
<em class="replaceable">
<code>
name
</code>
</em>
is the name of a plugin to
load. If a plugin library is named without any preceding
plugin name, the server loads all plugins in the library. With
a preceding plugin name, the server loads only the named
plugin from the library. The server looks for plugin library
files in the directory named by the
<a class="link" href="server-system-variables.html#sysvar_plugin_dir">
<code class="literal">
plugin_dir
</code>
</a>
system variable.
</p>
<p>
For example, if plugins named
<code class="literal">
myplug1
</code>
and
<code class="literal">
myplug2
</code>
are contained in the plugin library
files
<code class="filename">
myplug1.so
</code>
and
<code class="filename">
myplug2.so
</code>
, use this option to perform an
early plugin load:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa26541734"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal">mysqld <span class="token constant">--plugin-load</span>=<span class="token atrule">"myplug1=myplug1.so;myplug2=myplug2.so"</span></code></pre>
</div>
<p>
Quotes surround the argument value because otherwise some
command interpreters interpret semicolon
(
<code class="literal">
;
</code>
) as a special character. (For example,
Unix shells treat it as a command terminator.)
</p>
<p>
Each named plugin is loaded for a single invocation of
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
only. After a restart, the plugin is
not loaded unless
<a class="link" href="server-options.html#option_mysqld_plugin-load">
<code class="option">
--plugin-load
</code>
</a>
is used again. This is in contrast to
<a class="link" href="install-plugin.html" title="15.7.4.4 INSTALL PLUGIN Statement">
<code class="literal">
INSTALL PLUGIN
</code>
</a>
, which adds an
entry to the
<code class="literal">
mysql.plugins
</code>
table to cause
the plugin to be loaded for every normal server startup.
</p>
<p>
During the normal startup sequence, the server determines
which plugins to load by reading the
<code class="literal">
mysql.plugins
</code>
system table. If the server
is started with the
<a class="link" href="server-options.html#option_mysqld_skip-grant-tables">
<code class="option">
--skip-grant-tables
</code>
</a>
option,
plugins registered in the
<code class="literal">
mysql.plugins
</code>
table are not loaded and are unavailable.
<a class="link" href="server-options.html#option_mysqld_plugin-load">
<code class="option">
--plugin-load
</code>
</a>
enables plugins
to be loaded even when
<a class="link" href="server-options.html#option_mysqld_skip-grant-tables">
<code class="option">
--skip-grant-tables
</code>
</a>
is given.
<a class="link" href="server-options.html#option_mysqld_plugin-load">
<code class="option">
--plugin-load
</code>
</a>
also enables
plugins to be loaded at startup that cannot be loaded at
runtime.
</p>
<p>
This option does not set a corresponding system variable. The
output of
<a class="link" href="show-plugins.html" title="15.7.7.27 SHOW PLUGINS Statement">
<code class="literal">
SHOW PLUGINS
</code>
</a>
provides
information about loaded plugins. More detailed information
can be found in the Information Schema
<a class="link" href="information-schema-plugins-table.html" title="28.3.22 The INFORMATION_SCHEMA PLUGINS Table">
<code class="literal">
PLUGINS
</code>
</a>
table. See
<a class="xref" href="obtaining-plugin-information.html" title="7.6.2 Obtaining Server Plugin Information">
Section 7.6.2, “Obtaining Server Plugin Information”
</a>
.
</p>
<p>
For additional information about plugin loading, see
<a class="xref" href="plugin-loading.html" title="7.6.1 Installing and Uninstalling Plugins">
Section 7.6.1, “Installing and Uninstalling Plugins”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_plugin-load-add">
</a>
<a class="link" href="server-options.html#option_mysqld_plugin-load-add">
<code class="option">
--plugin-load-add=
<em class="replaceable">
<code>
plugin_list
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045279470256">
</a>
<a class="indexterm" name="idm46045279468768">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for plugin-load-add">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--plugin-load-add=plugin_list
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
</tbody>
</table>
</div>
<p>
This option complements the
<a class="link" href="server-options.html#option_mysqld_plugin-load">
<code class="option">
--plugin-load
</code>
</a>
option.
<a class="link" href="server-options.html#option_mysqld_plugin-load-add">
<code class="option">
--plugin-load-add
</code>
</a>
adds a plugin
or plugins to the set of plugins to be loaded at startup. The
argument format is the same as for
<a class="link" href="server-options.html#option_mysqld_plugin-load">
<code class="option">
--plugin-load
</code>
</a>
.
<a class="link" href="server-options.html#option_mysqld_plugin-load-add">
<code class="option">
--plugin-load-add
</code>
</a>
can be used
to avoid specifying a large set of plugins as a single long
unwieldy
<a class="link" href="server-options.html#option_mysqld_plugin-load">
<code class="option">
--plugin-load
</code>
</a>
argument.
</p>
<p>
<a class="link" href="server-options.html#option_mysqld_plugin-load-add">
<code class="option">
--plugin-load-add
</code>
</a>
can be given
in the absence of
<a class="link" href="server-options.html#option_mysqld_plugin-load">
<code class="option">
--plugin-load
</code>
</a>
, but any instance
of
<a class="link" href="server-options.html#option_mysqld_plugin-load-add">
<code class="option">
--plugin-load-add
</code>
</a>
that
appears before
<a class="link" href="server-options.html#option_mysqld_plugin-load">
<code class="option">
--plugin-load
</code>
</a>
.
has no effect because
<a class="link" href="server-options.html#option_mysqld_plugin-load">
<code class="option">
--plugin-load
</code>
</a>
resets the set of
plugins to load. In other words, these options:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa27421259"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token constant">--plugin-load</span><span class="token attr-value"><span class="token punctuation">=</span>x</span> <span class="token constant">--plugin-load-add</span><span class="token attr-value"><span class="token punctuation">=</span>y</span></code></pre>
</div>
<p>
are equivalent to this option:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa4221786"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token constant">--plugin-load</span>=<span class="token atrule">"x;y"</span></code></pre>
</div>
<p>
But these options:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa59364091"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token constant">--plugin-load-add</span><span class="token attr-value"><span class="token punctuation">=</span>y</span> <span class="token constant">--plugin-load</span><span class="token attr-value"><span class="token punctuation">=</span>x</span></code></pre>
</div>
<p>
are equivalent to this option:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa78493278"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token constant">--plugin-load</span><span class="token attr-value"><span class="token punctuation">=</span>x</span></code></pre>
</div>
<p>
This option does not set a corresponding system variable. The
output of
<a class="link" href="show-plugins.html" title="15.7.7.27 SHOW PLUGINS Statement">
<code class="literal">
SHOW PLUGINS
</code>
</a>
provides
information about loaded plugins. More detailed information
can be found in the Information Schema
<a class="link" href="information-schema-plugins-table.html" title="28.3.22 The INFORMATION_SCHEMA PLUGINS Table">
<code class="literal">
PLUGINS
</code>
</a>
table. See
<a class="xref" href="obtaining-plugin-information.html" title="7.6.2 Obtaining Server Plugin Information">
Section 7.6.2, “Obtaining Server Plugin Information”
</a>
.
</p>
<p>
For additional information about plugin loading, see
<a class="xref" href="plugin-loading.html" title="7.6.1 Installing and Uninstalling Plugins">
Section 7.6.1, “Installing and Uninstalling Plugins”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_plugin-xxx">
</a>
<a class="link" href="server-options.html#option_mysqld_plugin-xxx">
<code class="option">
--plugin-
<em class="replaceable">
<code>
xxx
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045279435184">
</a>
<a class="indexterm" name="idm46045279433696">
</a>
<p>
Specifies an option that pertains to a server plugin. For
example, many storage engines can be built as plugins, and for
such engines, options for them can be specified with a
<code class="option">
--plugin
</code>
prefix. Thus, the
<a class="link" href="innodb-parameters.html#sysvar_innodb_file_per_table">
<code class="option">
--innodb-file-per-table
</code>
</a>
option
for
<code class="literal">
InnoDB
</code>
can be specified as
<a class="link" href="innodb-parameters.html#sysvar_innodb_file_per_table">
<code class="option">
--plugin-innodb-file-per-table
</code>
</a>
.
</p>
<p>
For boolean options that can be enabled or disabled, the
<code class="option">
--skip
</code>
prefix and other alternative formats
are supported as well (see
<a class="xref" href="option-modifiers.html" title="6.2.2.4 Program Option Modifiers">
Section 6.2.2.4, “Program Option Modifiers”
</a>
). For example,
<a class="link" href="innodb-parameters.html#sysvar_innodb_file_per_table">
<code class="option">
--skip-plugin-innodb-file-per-table
</code>
</a>
disables
<a class="link" href="innodb-parameters.html#sysvar_innodb_file_per_table">
<code class="option">
innodb-file-per-table
</code>
</a>
.
</p>
<p>
The rationale for the
<code class="option">
--plugin
</code>
prefix is that
it enables plugin options to be specified unambiguously if
there is a name conflict with a built-in server option. For
example, were a plugin writer to name a plugin
<span class="quote">
“
<span class="quote">
sql
</span>
”
</span>
and implement a
<span class="quote">
“
<span class="quote">
mode
</span>
”
</span>
option,
the option name might be
<a class="link" href="server-options.html#option_mysqld_sql-mode">
<code class="option">
--sql-mode
</code>
</a>
, which would
conflict with the built-in option of the same name. In such
cases, references to the conflicting name are resolved in
favor of the built-in option. To avoid the ambiguity, users
can specify the plugin option as
<code class="option">
--plugin-sql-mode
</code>
. Use of the
<code class="option">
--plugin
</code>
prefix for plugin options is
recommended to avoid any question of ambiguity.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_port">
</a>
<a class="link" href="server-options.html#option_mysqld_port">
<code class="option">
--port=
<em class="replaceable">
<code>
port_num
</code>
</em>
</code>
</a>
,
<code class="option">
-P
<em class="replaceable">
<code>
port_num
</code>
</em>
</code>
</p>
<a class="indexterm" name="idm46045279417456">
</a>
<a class="indexterm" name="idm46045279415968">
</a>
<a class="indexterm" name="idm46045279414480">
</a>
<a class="indexterm" name="idm46045279413408">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for port">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--port=port_num
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="server-system-variables.html#sysvar_port">
port
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
3306
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
<tr>
<th>
Maximum Value
</th>
<td>
<code class="literal">
65535
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
The port number to use when listening for TCP/IP connections.
On Unix and Unix-like systems, the port number must be 1024 or
higher unless the server is started by the
<code class="literal">
root
</code>
operating system user. Setting this
option to 0 causes the default value to be used.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_port-open-timeout">
</a>
<a class="link" href="server-options.html#option_mysqld_port-open-timeout">
<code class="option">
--port-open-timeout=
<em class="replaceable">
<code>
num
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045279383328">
</a>
<a class="indexterm" name="idm46045279381872">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for port-open-timeout">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--port-open-timeout=#
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
On some systems, when the server is stopped, the TCP/IP port
might not become available immediately. If the server is
restarted quickly afterward, its attempt to reopen the port
can fail. This option indicates how many seconds the server
should wait for the TCP/IP port to become free if it cannot be
opened. The default is not to wait.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_print-defaults">
</a>
<a class="link" href="server-options.html#option_mysqld_print-defaults">
<code class="option">
--print-defaults
</code>
</a>
</p>
<a class="indexterm" name="idm46045279367408">
</a>
<a class="indexterm" name="idm46045279365920">
</a>
<p>
Print the program name and all options that it gets from
option files. Password values are masked. This must be the
first option on the command line if it is used, except that it
may be used immediately after
<a class="link" href="server-options.html#option_mysqld_defaults-file">
<code class="option">
--defaults-file
</code>
</a>
or
<a class="link" href="server-options.html#option_mysqld_defaults-extra-file">
<code class="option">
--defaults-extra-file
</code>
</a>
.
</p>
<p>
For additional information about this and other option-file
options, see
<a class="xref" href="option-file-options.html" title="6.2.2.3 Command-Line Options that Affect Option-File Handling">
Section 6.2.2.3, “Command-Line Options that Affect Option-File Handling”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_remove">
</a>
<a class="link" href="server-options.html#option_mysqld_remove">
<code class="option">
--remove
[
<em class="replaceable">
<code>
service_name
</code>
</em>
]
</code>
</a>
</p>
<a class="indexterm" name="idm46045279358192">
</a>
<a class="indexterm" name="idm46045279356704">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for remove">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--remove [service_name]
</code>
</td>
</tr>
<tr>
<th>
Platform Specific
</th>
<td>
Windows
</td>
</tr>
</tbody>
</table>
</div>
<p>
(Windows only) Remove a MySQL Windows service. The default
service name is
<code class="literal">
MySQL
</code>
if no
<em class="replaceable">
<code>
service_name
</code>
</em>
value is given. For
more information, see
<a class="xref" href="windows-start-service.html" title="2.3.3.8 Starting MySQL as a Windows Service">
Section 2.3.3.8, “Starting MySQL as a Windows Service”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_safe-user-create">
</a>
<a class="link" href="server-options.html#option_mysqld_safe-user-create">
<code class="option">
--safe-user-create
</code>
</a>
</p>
<a class="indexterm" name="idm46045279343120">
</a>
<a class="indexterm" name="idm46045279341632">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for safe-user-create">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--safe-user-create[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
Deprecated
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
If this option is enabled, a user cannot create new MySQL
users by using the
<a class="link" href="grant.html" title="15.7.1.6 GRANT Statement">
<code class="literal">
GRANT
</code>
</a>
statement unless the user has the
<a class="link" href="privileges-provided.html#priv_insert">
<code class="literal">
INSERT
</code>
</a>
privilege for the
<code class="literal">
mysql.user
</code>
system table or any column in
the table. If you want a user to have the ability to create
new users that have those privileges that the user has the
right to grant, you should grant the user the following
privilege:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa11226014"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">GRANT</span> <span class="token function">INSERT</span><span class="token punctuation">(</span><span class="token keyword">user</span><span class="token punctuation">)</span> <span class="token keyword">ON</span> mysql<span class="token punctuation">.</span><span class="token keyword">user</span> <span class="token keyword">TO</span> <span class="token string">'<em class="replaceable">user_name</em>'</span>@<span class="token string">'<em class="replaceable">host_name</em>'</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
This ensures that the user cannot change any privilege columns
directly, but has to use the
<a class="link" href="grant.html" title="15.7.1.6 GRANT Statement">
<code class="literal">
GRANT
</code>
</a>
statement to give
privileges to other users.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_skip-grant-tables">
</a>
<a class="link" href="server-options.html#option_mysqld_skip-grant-tables">
<code class="option">
--skip-grant-tables
</code>
</a>
</p>
<a class="indexterm" name="idm46045279318208">
</a>
<a class="indexterm" name="idm46045279316752">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for skip-grant-tables">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--skip-grant-tables[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
This option affects the server startup sequence:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
<a class="link" href="server-options.html#option_mysqld_skip-grant-tables">
<code class="option">
--skip-grant-tables
</code>
</a>
causes
the server not to read the grant tables in the
<code class="literal">
mysql
</code>
system schema, and thus to start
without using the privilege system at all. This gives
anyone with access to the server
<span class="emphasis">
<em>
unrestricted
access to all databases
</em>
</span>
.
</p>
<p>
Because starting the server with
<a class="link" href="server-options.html#option_mysqld_skip-grant-tables">
<code class="option">
--skip-grant-tables
</code>
</a>
disables authentication checks, the server also disables
remote connections in that case by enabling
<a class="link" href="server-system-variables.html#sysvar_skip_networking">
<code class="literal">
skip_networking
</code>
</a>
.
</p>
<p>
To cause a server started with
<a class="link" href="server-options.html#option_mysqld_skip-grant-tables">
<code class="option">
--skip-grant-tables
</code>
</a>
to load
the grant tables at runtime, perform a privilege-flushing
operation, which can be done in these ways:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: square; ">
<li class="listitem">
<p>
Issue a MySQL
<a class="link" href="flush.html#flush-privileges">
<code class="literal">
FLUSH
PRIVILEGES
</code>
</a>
statement after connecting to the
server.
</p>
</li>
<li class="listitem">
<p>
Execute a
<a class="link" href="mysqladmin.html" title="6.5.2 mysqladmin — A MySQL Server Administration Program">
<span class="command">
<strong>
mysqladmin
flush-privileges
</strong>
</span>
</a>
or
<a class="link" href="mysqladmin.html" title="6.5.2 mysqladmin — A MySQL Server Administration Program">
<span class="command">
<strong>
mysqladmin
reload
</strong>
</span>
</a>
command from the command line.
</p>
</li>
</ul>
</div>
<p>
Privilege flushing might also occur implicitly as a result
of other actions performed after startup, thus causing the
server to start using the grant tables. For example, the
server flushes the privileges if it performs an upgrade
during the startup sequence.
</p>
</li>
<li class="listitem">
<p>
<a class="link" href="server-options.html#option_mysqld_skip-grant-tables">
<code class="option">
--skip-grant-tables
</code>
</a>
disables failed-login tracking and temporary account
locking because those capabilities depend on the grant
tables. See
<a class="xref" href="password-management.html" title="8.2.15 Password Management">
Section 8.2.15, “Password Management”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a class="link" href="server-options.html#option_mysqld_skip-grant-tables">
<code class="option">
--skip-grant-tables
</code>
</a>
causes
the server not to load certain other objects registered in
the data dictionary or the
<code class="literal">
mysql
</code>
system
schema:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: square; ">
<li class="listitem">
<p>
Scheduled events installed using
<a class="link" href="create-event.html" title="15.1.13 CREATE EVENT Statement">
<code class="literal">
CREATE EVENT
</code>
</a>
and
registered in the
<code class="literal">
events
</code>
data
dictionary table.
</p>
</li>
<li class="listitem">
<p>
Plugins installed using
<a class="link" href="install-plugin.html" title="15.7.4.4 INSTALL PLUGIN Statement">
<code class="literal">
INSTALL
PLUGIN
</code>
</a>
and registered in the
<code class="literal">
mysql.plugin
</code>
system table.
</p>
<p>
To cause plugins to be loaded even when using
<a class="link" href="server-options.html#option_mysqld_skip-grant-tables">
<code class="option">
--skip-grant-tables
</code>
</a>
,
use the
<a class="link" href="server-options.html#option_mysqld_plugin-load">
<code class="option">
--plugin-load
</code>
</a>
or
<a class="link" href="server-options.html#option_mysqld_plugin-load-add">
<code class="option">
--plugin-load-add
</code>
</a>
option.
</p>
</li>
<li class="listitem">
<p>
Loadable functions installed using
<a class="link" href="create-function-loadable.html" title="15.7.4.1 CREATE FUNCTION Statement for Loadable Functions">
<code class="literal">
CREATE
FUNCTION
</code>
</a>
and registered in the
<code class="literal">
mysql.func
</code>
system table.
</p>
</li>
</ul>
</div>
<p>
<a class="link" href="server-options.html#option_mysqld_skip-grant-tables">
<code class="option">
--skip-grant-tables
</code>
</a>
does
<span class="emphasis">
<em>
not
</em>
</span>
suppress loading during startup
of components.
</p>
</li>
<li class="listitem">
<p>
<a class="link" href="server-options.html#option_mysqld_skip-grant-tables">
<code class="option">
--skip-grant-tables
</code>
</a>
causes
the
<a class="link" href="server-system-variables.html#sysvar_disabled_storage_engines">
<code class="literal">
disabled_storage_engines
</code>
</a>
system variable to have no effect.
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_skip-new">
</a>
<a class="link" href="server-options.html#option_mysqld_skip-new">
<code class="option">
--skip-new
</code>
</a>
</p>
<a class="indexterm" name="idm46045279265056">
</a>
<a class="indexterm" name="idm46045279263568">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for skip-new">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--skip-new
</code>
</td>
</tr>
<tr>
<th>
Deprecated
</th>
<td>
Yes
</td>
</tr>
</tbody>
</table>
</div>
<p>
This option disables (what used to be considered) new,
possibly unsafe behaviors. It results in these settings:
<a class="link" href="server-system-variables.html#sysvar_delay_key_write">
<code class="literal">
delay_key_write=OFF
</code>
</a>
,
<a class="link" href="server-system-variables.html#sysvar_concurrent_insert">
<code class="literal">
concurrent_insert=NEVER
</code>
</a>
,
<a class="link" href="server-system-variables.html#sysvar_automatic_sp_privileges">
<code class="literal">
automatic_sp_privileges=OFF
</code>
</a>
.
It also causes
<a class="link" href="optimize-table.html" title="15.7.3.4 OPTIMIZE TABLE Statement">
<code class="literal">
OPTIMIZE TABLE
</code>
</a>
to be mapped to
<a class="link" href="alter-table.html" title="15.1.9 ALTER TABLE Statement">
<code class="literal">
ALTER TABLE
</code>
</a>
for
storage engines for which
<a class="link" href="optimize-table.html" title="15.7.3.4 OPTIMIZE TABLE Statement">
<code class="literal">
OPTIMIZE
TABLE
</code>
</a>
is not supported.
</p>
<p>
This option is deprecated, and subject to removal in a future
release.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_skip-show-database">
</a>
<a class="link" href="server-options.html#option_mysqld_skip-show-database">
<code class="option">
--skip-show-database
</code>
</a>
</p>
<a class="indexterm" name="idm46045279243776">
</a>
<a class="indexterm" name="idm46045279242320">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for skip-show-database">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--skip-show-database
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="server-system-variables.html#sysvar_skip_show_database">
skip_show_database
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
This option sets the
<a class="link" href="server-system-variables.html#sysvar_skip_show_database">
<code class="literal">
skip_show_database
</code>
</a>
system
variable that controls who is permitted to use the
<a class="link" href="show-databases.html" title="15.7.7.15 SHOW DATABASES Statement">
<code class="literal">
SHOW DATABASES
</code>
</a>
statement. See
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_skip-stack-trace">
</a>
<a class="link" href="server-options.html#option_mysqld_skip-stack-trace">
<code class="option">
--skip-stack-trace
</code>
</a>
</p>
<a class="indexterm" name="idm46045279214640">
</a>
<a class="indexterm" name="idm46045279213152">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for skip-stack-trace">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--skip-stack-trace
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Do not write stack traces. This option is useful when you are
running
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
under a debugger. On some
systems, you also must use this option to get a core file. See
<a class="xref" href="debugging-mysql.html" title="7.9 Debugging MySQL">
Section 7.9, “Debugging MySQL”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_slow-start-timeout">
</a>
<a class="link" href="server-options.html#option_mysqld_slow-start-timeout">
<code class="option">
--slow-start-timeout=
<em class="replaceable">
<code>
timeout
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045279201168">
</a>
<a class="indexterm" name="idm46045279199712">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for slow-start-timeout">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--slow-start-timeout=#
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
15000
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
This option controls the Windows service control manager's
service start timeout. The value is the maximum number of
milliseconds that the service control manager waits before
trying to kill the windows service during startup. The default
value is 15000 (15 seconds). If the MySQL service takes too
long to start, you may need to increase this value. A value of
0 means there is no timeout.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_socket">
</a>
<a class="link" href="server-options.html#option_mysqld_socket">
<code class="option">
--socket=
<em class="replaceable">
<code>
path
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045279184976">
</a>
<a class="indexterm" name="idm46045279183488">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for socket">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--socket={file_name|pipe_name}
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="server-system-variables.html#sysvar_socket">
socket
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value (Windows)
</th>
<td>
<code class="literal">
MySQL
</code>
</td>
</tr>
<tr>
<th>
Default Value (Other)
</th>
<td>
<code class="literal">
/tmp/mysql.sock
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
On Unix, this option specifies the Unix socket file to use
when listening for local connections. The default value is
<code class="filename">
/tmp/mysql.sock
</code>
. If this option is given,
the server creates the file in the data directory unless an
absolute path name is given to specify a different directory.
On Windows, the option specifies the pipe name to use when
listening for local connections that use a named pipe. The
default value is
<code class="literal">
MySQL
</code>
(not
case-sensitive).
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_sql-mode">
</a>
<a class="link" href="server-options.html#option_mysqld_sql-mode">
<code class="option">
--sql-mode=
<em class="replaceable">
<code>
value
</code>
</em>
[,
<em class="replaceable">
<code>
value
</code>
</em>
[,
<em class="replaceable">
<code>
value
</code>
</em>
...]]
</code>
</a>
</p>
<a class="indexterm" name="idm46045279153152">
</a>
<a class="indexterm" name="idm46045279151664">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for sql-mode">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--sql-mode=name
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="server-system-variables.html#sysvar_sql_mode">
sql_mode
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global, Session
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Set
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
ONLY_FULL_GROUP_BY STRICT_TRANS_TABLES NO_ZERO_IN_DATE NO_ZERO_DATE ERROR_FOR_DIVISION_BY_ZERO NO_ENGINE_SUBSTITUTION
</code>
</td>
</tr>
<tr>
<th>
Valid Values
</th>
<td>
<p class="valid-value">
<code class="literal">
ALLOW_INVALID_DATES
</code>
</p>
<p class="valid-value">
<code class="literal">
ANSI_QUOTES
</code>
</p>
<p class="valid-value">
<code class="literal">
ERROR_FOR_DIVISION_BY_ZERO
</code>
</p>
<p class="valid-value">
<code class="literal">
HIGH_NOT_PRECEDENCE
</code>
</p>
<p class="valid-value">
<code class="literal">
IGNORE_SPACE
</code>
</p>
<p class="valid-value">
<code class="literal">
NO_AUTO_VALUE_ON_ZERO
</code>
</p>
<p class="valid-value">
<code class="literal">
NO_BACKSLASH_ESCAPES
</code>
</p>
<p class="valid-value">
<code class="literal">
NO_DIR_IN_CREATE
</code>
</p>
<p class="valid-value">
<code class="literal">
NO_ENGINE_SUBSTITUTION
</code>
</p>
<p class="valid-value">
<code class="literal">
NO_UNSIGNED_SUBTRACTION
</code>
</p>
<p class="valid-value">
<code class="literal">
NO_ZERO_DATE
</code>
</p>
<p class="valid-value">
<code class="literal">
NO_ZERO_IN_DATE
</code>
</p>
<p class="valid-value">
<code class="literal">
ONLY_FULL_GROUP_BY
</code>
</p>
<p class="valid-value">
<code class="literal">
PAD_CHAR_TO_FULL_LENGTH
</code>
</p>
<p class="valid-value">
<code class="literal">
PIPES_AS_CONCAT
</code>
</p>
<p class="valid-value">
<code class="literal">
REAL_AS_FLOAT
</code>
</p>
<p class="valid-value">
<code class="literal">
STRICT_ALL_TABLES
</code>
</p>
<p class="valid-value">
<code class="literal">
STRICT_TRANS_TABLES
</code>
</p>
<p class="valid-value">
<code class="literal">
TIME_TRUNCATE_FRACTIONAL
</code>
</p>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Set the SQL mode. See
<a class="xref" href="sql-mode.html" title="7.1.11 Server SQL Modes">
Section 7.1.11, “Server SQL Modes”
</a>
.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
MySQL installation programs may configure the SQL mode
during the installation process.
</p>
<p>
If the SQL mode differs from the default or from what you
expect, check for a setting in an option file that the
server reads at startup.
</p>
</div>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_standalone">
</a>
<a class="link" href="server-options.html#option_mysqld_standalone">
<code class="option">
--standalone
</code>
</a>
</p>
<a class="indexterm" name="idm46045279104992">
</a>
<a class="indexterm" name="idm46045279103504">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for standalone">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--standalone
</code>
</td>
</tr>
<tr>
<th>
Platform Specific
</th>
<td>
Windows
</td>
</tr>
</tbody>
</table>
</div>
<p>
Available on Windows only; instructs the MySQL server not to
run as a service.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_super-large-pages">
</a>
<a class="link" href="server-options.html#option_mysqld_super-large-pages">
<code class="option">
--super-large-pages
</code>
</a>
</p>
<a class="indexterm" name="idm46045279091808">
</a>
<a class="indexterm" name="idm46045279090352">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for super-large-pages">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--super-large-pages[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
Platform Specific
</th>
<td>
Solaris
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Standard use of large pages in MySQL attempts to use the
largest size supported, up to 4MB. Under Solaris, a
<span class="quote">
“
<span class="quote">
super large pages
</span>
”
</span>
feature enables uses of pages
up to 256MB. This feature is available for recent SPARC
platforms. It can be enabled or disabled by using the
<a class="link" href="server-options.html#option_mysqld_super-large-pages">
<code class="option">
--super-large-pages
</code>
</a>
or
<a class="link" href="server-options.html#option_mysqld_super-large-pages">
<code class="option">
--skip-super-large-pages
</code>
</a>
option.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_symbolic-links">
</a>
<a class="link" href="server-options.html#option_mysqld_symbolic-links">
<code class="option">
--symbolic-links
</code>
</a>
,
<a class="link" href="server-options.html#option_mysqld_symbolic-links">
<code class="option">
--skip-symbolic-links
</code>
</a>
</p>
<a class="indexterm" name="idm46045279070464">
</a>
<a class="indexterm" name="idm46045279068976">
</a>
<a class="indexterm" name="idm46045279067488">
</a>
<a class="indexterm" name="idm46045279066032">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for symbolic-links">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--symbolic-links[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
Deprecated
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Enable or disable symbolic link support. On Unix, enabling
symbolic links means that you can link a
<code class="literal">
MyISAM
</code>
index file or data file to another
directory with the
<code class="literal">
INDEX DIRECTORY
</code>
or
<code class="literal">
DATA DIRECTORY
</code>
option of the
<a class="link" href="create-table.html" title="15.1.20 CREATE TABLE Statement">
<code class="literal">
CREATE TABLE
</code>
</a>
statement. If you
delete or rename the table, the files that its symbolic links
point to also are deleted or renamed. See
<a class="xref" href="symbolic-links-to-tables.html" title="10.12.2.2 Using Symbolic Links for MyISAM Tables on Unix">
Section 10.12.2.2, “Using Symbolic Links for MyISAM Tables on Unix”
</a>
.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
Symbolic link support, along with the
<a class="link" href="server-options.html#option_mysqld_symbolic-links">
<code class="option">
--symbolic-links
</code>
</a>
option that
controls it, is deprecated; you should expect it to be
removed in a future version of MySQL. In addition, the
option is disabled by default. The related
<a class="link" href="server-system-variables.html#sysvar_have_symlink">
<code class="literal">
have_symlink
</code>
</a>
system
variable also is deprecated; expect it to be removed in a
future version of MySQL.
</p>
</div>
<p>
This option has no meaning on Windows.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_sysdate-is-now">
</a>
<a class="link" href="server-options.html#option_mysqld_sysdate-is-now">
<code class="option">
--sysdate-is-now
</code>
</a>
</p>
<a class="indexterm" name="idm46045279041552">
</a>
<a class="indexterm" name="idm46045279040064">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for sysdate-is-now">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--sysdate-is-now[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
<a class="link" href="date-and-time-functions.html#function_sysdate">
<code class="literal">
SYSDATE()
</code>
</a>
by default returns
the time at which it executes, not the time at which the
statement in which it occurs begins executing. This differs
from the behavior of
<a class="link" href="date-and-time-functions.html#function_now">
<code class="literal">
NOW()
</code>
</a>
.
This option causes
<a class="link" href="date-and-time-functions.html#function_sysdate">
<code class="literal">
SYSDATE()
</code>
</a>
to
be a synonym for
<a class="link" href="date-and-time-functions.html#function_now">
<code class="literal">
NOW()
</code>
</a>
. For
information about the implications for binary logging and
replication, see the description for
<a class="link" href="date-and-time-functions.html#function_sysdate">
<code class="literal">
SYSDATE()
</code>
</a>
in
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
and for
<code class="literal">
SET
TIMESTAMP
</code>
in
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_tc-heuristic-recover">
</a>
<a class="link" href="server-options.html#option_mysqld_tc-heuristic-recover">
<code class="option">
--tc-heuristic-recover={COMMIT|ROLLBACK}
</code>
</a>
</p>
<a class="indexterm" name="idm46045279017072">
</a>
<a class="indexterm" name="idm46045279015616">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for tc-heuristic-recover">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--tc-heuristic-recover=name
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Enumeration
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
<tr>
<th>
Valid Values
</th>
<td>
<p class="valid-value">
<code class="literal">
OFF
</code>
</p>
<p class="valid-value">
<code class="literal">
COMMIT
</code>
</p>
<p class="valid-value">
<code class="literal">
ROLLBACK
</code>
</p>
</td>
</tr>
</tbody>
</table>
</div>
<p>
The decision to use in a manual heuristic recovery.
</p>
<p>
If a
<code class="literal">
--tc-heuristic-recover
</code>
option is
specified, the server exits regardless of whether manual
heuristic recovery is successful.
</p>
<p>
On systems with more than one storage engine capable of
two-phase commit, the
<code class="literal">
ROLLBACK
</code>
option is
not safe and causes recovery to halt with the following error:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-terminal"><div class="docs-select-all right" id="sa91100660"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token property"><span class="token punctuation">[</span>ERROR<span class="token punctuation">]</span></span> <span class="token property">--tc-heuristic-recover</span> rollback
strategy is not safe on systems with more than one 2-phase-commit-capable
storage engine<span class="token punctuation">.</span> Aborting crash recovery<span class="token punctuation">.</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_transaction-isolation">
</a>
<a class="link" href="server-options.html#option_mysqld_transaction-isolation">
<code class="option">
--transaction-isolation=
<em class="replaceable">
<code>
level
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045278992832">
</a>
<a class="indexterm" name="idm46045278991328">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for transaction-isolation">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--transaction-isolation=name
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="server-system-variables.html#sysvar_transaction_isolation">
transaction_isolation
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global, Session
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Enumeration
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
REPEATABLE-READ
</code>
</td>
</tr>
<tr>
<th>
Valid Values
</th>
<td>
<p class="valid-value">
<code class="literal">
READ-UNCOMMITTED
</code>
</p>
<p class="valid-value">
<code class="literal">
READ-COMMITTED
</code>
</p>
<p class="valid-value">
<code class="literal">
REPEATABLE-READ
</code>
</p>
<p class="valid-value">
<code class="literal">
SERIALIZABLE
</code>
</p>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Sets the default transaction isolation level. The
<code class="literal">
level
</code>
value can be
<a class="link" href="innodb-transaction-isolation-levels.html#isolevel_read-uncommitted">
<code class="literal">
READ-UNCOMMITTED
</code>
</a>
,
<a class="link" href="innodb-transaction-isolation-levels.html#isolevel_read-committed">
<code class="literal">
READ-COMMITTED
</code>
</a>
,
<a class="link" href="innodb-transaction-isolation-levels.html#isolevel_repeatable-read">
<code class="literal">
REPEATABLE-READ
</code>
</a>
, or
<a class="link" href="innodb-transaction-isolation-levels.html#isolevel_serializable">
<code class="literal">
SERIALIZABLE
</code>
</a>
. See
<a class="xref" href="set-transaction.html" title="15.3.7 SET TRANSACTION Statement">
Section 15.3.7, “SET TRANSACTION Statement”
</a>
.
</p>
<p>
The default transaction isolation level can also be set at
runtime using the
<a class="link" href="set-transaction.html" title="15.3.7 SET TRANSACTION Statement">
<code class="literal">
SET
TRANSACTION
</code>
</a>
statement or by setting the
<a class="link" href="server-system-variables.html#sysvar_transaction_isolation">
<code class="literal">
transaction_isolation
</code>
</a>
system
variable.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_transaction-read-only">
</a>
<a class="link" href="server-options.html#option_mysqld_transaction-read-only">
<code class="option">
--transaction-read-only
</code>
</a>
</p>
<a class="indexterm" name="idm46045278950960">
</a>
<a class="indexterm" name="idm46045278949504">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for transaction-read-only">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--transaction-read-only[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="server-system-variables.html#sysvar_transaction_read_only">
transaction_read_only
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global, Session
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Sets the default transaction access mode. By default,
read-only mode is disabled, so the mode is read/write.
</p>
<p>
To set the default transaction access mode at runtime, use the
<a class="link" href="set-transaction.html" title="15.3.7 SET TRANSACTION Statement">
<code class="literal">
SET TRANSACTION
</code>
</a>
statement or
set the
<a class="link" href="server-system-variables.html#sysvar_transaction_read_only">
<code class="literal">
transaction_read_only
</code>
</a>
system variable. See
<a class="xref" href="set-transaction.html" title="15.3.7 SET TRANSACTION Statement">
Section 15.3.7, “SET TRANSACTION Statement”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_tmpdir">
</a>
<a class="link" href="server-options.html#option_mysqld_tmpdir">
<code class="option">
--tmpdir=
<em class="replaceable">
<code>
dir_name
</code>
</em>
</code>
</a>
,
<code class="option">
-t
<em class="replaceable">
<code>
dir_name
</code>
</em>
</code>
</p>
<a class="indexterm" name="idm46045278920448">
</a>
<a class="indexterm" name="idm46045278918960">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for tmpdir">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--tmpdir=dir_name
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="server-system-variables.html#sysvar_tmpdir">
tmpdir
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
No
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Directory name
</td>
</tr>
</tbody>
</table>
</div>
<p>
The path of the directory to use for creating temporary files.
It might be useful if your default
<code class="literal">
/tmp
</code>
directory resides on a partition that is too small to hold
temporary tables. This option accepts several paths that are
used in round-robin fashion. Paths should be separated by
colon characters (
<code class="literal">
:
</code>
) on Unix and semicolon
characters (
<code class="literal">
;
</code>
) on Windows.
</p>
<p>
<a class="link" href="server-options.html#option_mysqld_tmpdir">
<code class="option">
--tmpdir
</code>
</a>
can be a non-permanent
location, such as a directory on a memory-based file system or
a directory that is cleared when the server host restarts. If
the MySQL server is acting as a replica, and you are using a
non-permanent location for
<a class="link" href="server-options.html#option_mysqld_tmpdir">
<code class="option">
--tmpdir
</code>
</a>
, consider setting a
different temporary directory for the replica using the
<a class="link" href="replication-options-replica.html#sysvar_replica_load_tmpdir">
<code class="literal">
replica_load_tmpdir
</code>
</a>
system
variable. For a replica, the temporary files used to replicate
<a class="link" href="load-data.html" title="15.2.9 LOAD DATA Statement">
<code class="literal">
LOAD DATA
</code>
</a>
statements are stored
in this directory, so with a permanent location they can
survive machine restarts, although replication can now
continue after a restart if the temporary files have been
removed.
</p>
<p>
For more information about the storage location of temporary
files, see
<a class="xref" href="temporary-files.html" title="B.3.3.5 Where MySQL Stores Temporary Files">
Section B.3.3.5, “Where MySQL Stores Temporary Files”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_upgrade">
</a>
<a class="link" href="server-options.html#option_mysqld_upgrade">
<code class="option">
--upgrade=
<em class="replaceable">
<code>
value
</code>
</em>
</code>
</a>
</p>
<a class="indexterm" name="idm46045278887712">
</a>
<a class="indexterm" name="idm46045278886224">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for upgrade">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--upgrade=value
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Enumeration
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
AUTO
</code>
</td>
</tr>
<tr>
<th>
Valid Values
</th>
<td>
<p class="valid-value">
<code class="literal">
AUTO
</code>
</p>
<p class="valid-value">
<code class="literal">
NONE
</code>
</p>
<p class="valid-value">
<code class="literal">
MINIMAL
</code>
</p>
<p class="valid-value">
<code class="literal">
FORCE
</code>
</p>
</td>
</tr>
</tbody>
</table>
</div>
<p>
This option controls whether and how the server performs an
automatic upgrade at startup. Automatic upgrade involves two
steps:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
Step 1: Data dictionary upgrade.
</p>
<p>
This step upgrades:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: square; ">
<li class="listitem">
<p>
The data dictionary tables in the
<code class="literal">
mysql
</code>
schema. If the actual data
dictionary version is lower than the current expected
version, the server upgrades the data dictionary. If
it cannot, or is prevented from doing so, the server
cannot run.
</p>
</li>
<li class="listitem">
<p>
The Performance Schema and
<code class="literal">
INFORMATION_SCHEMA
</code>
.
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
Step 2: Server upgrade.
</p>
<p>
This step comprises all other upgrade tasks. If the
existing installation data has a lower MySQL version than
the server expects, it must be upgraded:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: square; ">
<li class="listitem">
<p>
The system tables in the
<code class="literal">
mysql
</code>
schema (the remaining non-data dictionary tables).
</p>
</li>
<li class="listitem">
<p>
The
<code class="literal">
sys
</code>
schema.
</p>
</li>
<li class="listitem">
<p>
User schemas.
</p>
</li>
</ul>
</div>
</li>
</ul>
</div>
<p>
For details about upgrade steps 1 and 2, see
<a class="xref" href="upgrading-what-is-upgraded.html" title="3.4 What the MySQL Upgrade Process Upgrades">
Section 3.4, “What the MySQL Upgrade Process Upgrades”
</a>
.
</p>
<p>
These
<a class="link" href="server-options.html#option_mysqld_upgrade">
<code class="option">
--upgrade
</code>
</a>
option values
are permitted:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
<code class="literal">
AUTO
</code>
</p>
<p>
The server performs an automatic upgrade of anything it
finds to be out of date (steps 1 and 2). This is the
default action if
<a class="link" href="server-options.html#option_mysqld_upgrade">
<code class="option">
--upgrade
</code>
</a>
is not specified explicitly.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
NONE
</code>
</p>
<p>
The server performs no automatic upgrade steps during the
startup process (skips steps 1 and 2). Because this option
value prevents a data dictionary upgrade, the server exits
with an error if the data dictionary is found to be out of
date:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-none"><div class="docs-select-all right" id="sa16347920"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-none">[ERROR] [MY-013381] [Server] Server shutting down because upgrade is
required, yet prohibited by the command line option '--upgrade=NONE'.
[ERROR] [MY-010334] [Server] Failed to initialize DD Storage Engine
[ERROR] [MY-010020] [Server] Data Dictionary initialization failed.</code></pre>
</div>
</li>
<li class="listitem">
<p>
<code class="literal">
MINIMAL
</code>
</p>
<p>
The server upgrades the data dictionary, the Performance
Schema, and the
<code class="literal">
INFORMATION_SCHEMA
</code>
, if
necessary (step 1). Note that following an upgrade with
this option, Group Replication cannot be started, because
system tables on which the replication internals depend
are not updated, and reduced functionality might also be
apparent in other areas.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
FORCE
</code>
</p>
<p>
The server upgrades the data dictionary, the Performance
Schema, and the
<code class="literal">
INFORMATION_SCHEMA
</code>
, if
necessary (step 1). In addition, the server forces an
upgrade of everything else (step 2). Expect server startup
to take longer with this option because the server checks
all objects in all schemas.
</p>
<p>
<code class="literal">
FORCE
</code>
is useful to force step 2 actions
to be performed if the server thinks they are not
necessary. For example, you may believe that a system
table is missing or has become damaged and want to force a
repair.
</p>
</li>
</ul>
</div>
<p>
The following table summarizes the actions taken by the server
for each option value.
</p>
<div class="informaltable">
<table summary="Upgrade actions performed for each --upgrade option value.">
<colgroup>
<col style="width: 20%"/>
<col style="width: 30%"/>
<col style="width: 30%"/>
</colgroup>
<thead>
<tr>
<th scope="col">
Option Value
</th>
<th scope="col">
Server Performs Step 1?
</th>
<th scope="col">
Server Performs Step 2?
</th>
</tr>
</thead>
<tbody>
<tr>
<th scope="row">
<code class="literal">
AUTO
</code>
</th>
<td>
If necessary
</td>
<td>
If necessary
</td>
</tr>
<tr>
<th scope="row">
<code class="literal">
NONE
</code>
</th>
<td>
No
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<code class="literal">
MINIMAL
</code>
</th>
<td>
If necessary
</td>
<td>
No
</td>
</tr>
<tr>
<th scope="row">
<code class="literal">
FORCE
</code>
</th>
<td>
If necessary
</td>
<td>
Yes
</td>
</tr>
</tbody>
</table>
</div>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_user">
</a>
<a class="link" href="server-options.html#option_mysqld_user">
<code class="option">
--user={
<em class="replaceable">
<code>
user_name
</code>
</em>
|
<em class="replaceable">
<code>
user_id
</code>
</em>
}
</code>
</a>
,
<code class="option">
-u
{
<em class="replaceable">
<code>
user_name
</code>
</em>
|
<em class="replaceable">
<code>
user_id
</code>
</em>
}
</code>
</p>
<a class="indexterm" name="idm46045278813488">
</a>
<a class="indexterm" name="idm46045278812000">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for user">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--user=name
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
</tbody>
</table>
</div>
<p>
Run the
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
server as the user having
the name
<em class="replaceable">
<code>
user_name
</code>
</em>
or the numeric
user ID
<em class="replaceable">
<code>
user_id
</code>
</em>
.
(
<span class="quote">
“
<span class="quote">
User
</span>
”
</span>
in this context refers to a system login
account, not a MySQL user listed in the grant tables.)
</p>
<p>
This option is
<span class="emphasis">
<em>
mandatory
</em>
</span>
when starting
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
as
<code class="literal">
root
</code>
. The
server changes its user ID during its startup sequence,
causing it to run as that particular user rather than as
<code class="literal">
root
</code>
. See
<a class="xref" href="security-guidelines.html" title="8.1.1 Security Guidelines">
Section 8.1.1, “Security Guidelines”
</a>
.
</p>
<p>
To avoid a possible security hole where a user adds a
<a class="link" href="server-options.html#option_mysqld_user">
<code class="option">
--user=root
</code>
</a>
option to a
<code class="filename">
my.cnf
</code>
file (thus causing the server to
run as
<code class="literal">
root
</code>
),
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
uses only the first
<a class="link" href="server-options.html#option_mysqld_user">
<code class="option">
--user
</code>
</a>
option specified and produces a warning if there are multiple
<a class="link" href="server-options.html#option_mysqld_user">
<code class="option">
--user
</code>
</a>
options. Options in
<code class="filename">
/etc/my.cnf
</code>
and
<code class="filename">
$MYSQL_HOME/my.cnf
</code>
are processed before
command-line options, so it is recommended that you put a
<a class="link" href="server-options.html#option_mysqld_user">
<code class="option">
--user
</code>
</a>
option in
<code class="filename">
/etc/my.cnf
</code>
and specify a value other
than
<code class="literal">
root
</code>
. The option in
<code class="filename">
/etc/my.cnf
</code>
is found before any other
<a class="link" href="server-options.html#option_mysqld_user">
<code class="option">
--user
</code>
</a>
options, which ensures
that the server runs as a user other than
<code class="literal">
root
</code>
, and that a warning results if any
other
<a class="link" href="server-options.html#option_mysqld_user">
<code class="option">
--user
</code>
</a>
option is found.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_validate-config">
</a>
<a class="link" href="server-options.html#option_mysqld_validate-config">
<code class="option">
--validate-config
</code>
</a>
</p>
<a class="indexterm" name="idm46045278779408">
</a>
<a class="indexterm" name="idm46045278777920">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate-config">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-config[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
OFF
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Validate the server startup configuration. If no errors are
found, the server terminates with an exit code of 0. If an
error is found, the server displays a diagnostic message and
terminates with an exit code of 1. Warning and information
messages may also be displayed, depending on the
<a class="link" href="server-system-variables.html#sysvar_log_error_verbosity">
<code class="literal">
log_error_verbosity
</code>
</a>
value,
but do not produce immediate validation termination or an exit
code of 1. For more information, see
<a class="xref" href="server-configuration-validation.html" title="7.1.3 Server Configuration Validation">
Section 7.1.3, “Server Configuration Validation”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_validate-user-plugins">
</a>
<a class="link" href="server-options.html#option_mysqld_validate-user-plugins">
<code class="option">
--validate-user-plugins[={OFF|ON}]
</code>
</a>
</p>
<a class="indexterm" name="idm46045278761360">
</a>
<a class="indexterm" name="idm46045278759856">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate-user-plugins">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-user-plugins[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
ON
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
If this option is enabled (the default), the server checks
each user account and produces a warning if conditions are
found that would make the account unusable:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
The account requires an authentication plugin that is not
loaded.
</p>
</li>
<li class="listitem">
<p>
The account requires the
<code class="literal">
sha256_password
</code>
(deprecated) or
<code class="literal">
caching_sha2_password
</code>
authentication
plugin but the server was started with neither SSL nor RSA
enabled as required by the plugin.
</p>
</li>
</ul>
</div>
<p>
Enabling
<a class="link" href="server-options.html#option_mysqld_validate-user-plugins">
<code class="option">
--validate-user-plugins
</code>
</a>
slows
down server initialization and
<a class="link" href="flush.html#flush-privileges">
<code class="literal">
FLUSH
PRIVILEGES
</code>
</a>
. If you do not require the additional
checking, you can disable this option at startup to avoid the
performance decrement.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_verbose">
</a>
<a class="link" href="server-options.html#option_mysqld_verbose">
<code class="option">
--verbose
</code>
</a>
,
<a class="link" href="server-options.html#option_mysqld_verbose">
<code class="option">
-v
</code>
</a>
</p>
<a class="indexterm" name="idm46045278738112">
</a>
<a class="indexterm" name="idm46045278736656">
</a>
<p>
Use this option with the
<a class="link" href="server-options.html#option_mysqld_help">
<code class="option">
--help
</code>
</a>
option for detailed help.
</p>
</li>
<li class="listitem">
<p>
<a name="option_mysqld_version">
</a>
<a class="link" href="server-options.html#option_mysqld_version">
<code class="option">
--version
</code>
</a>
,
<code class="option">
-V
</code>
</p>
<a class="indexterm" name="idm46045278731056">
</a>
<a class="indexterm" name="idm46045278729568">
</a>
<p>
Display version information and exit.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
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<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="windows-choosing-package">
</a>
2.3.1 Choosing an Installation Package
</h3>
</div>
</div>
</div>
<p>
For MySQL 8.4, there are multiple installation
package formats to choose from when installing MySQL on Windows.
The package formats described in this section are:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="xref" href="windows-choosing-package.html#windows-choosing-package-mysql-installer" title="MySQL Installation MSI">
MySQL Installation MSI
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="windows-choosing-package.html#windows-choosing-package-no-zip" title="MySQL noinstall ZIP Archives">
MySQL noinstall ZIP Archives
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="windows-choosing-package.html#windows-choosing-package-docker" title="MySQL Docker Images">
MySQL Docker Images
</a>
</p>
</li>
</ul>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="windows-choosing-package-mysql-installer">
</a>
MySQL Installation MSI
</h4>
</div>
</div>
</div>
<p>
This package has a file name similar to
<code class="filename">
mysql-community-8.4.3.msi
</code>
or
<code class="filename">
mysql-commercial-8.4.3.msi
</code>
, and
installs MySQL server along with MySQL Configurator. The MSI includes a
MySQL Configurator application that is recommended for most users to set
up, configure, and reconfigure the MySQL server.
</p>
<p>
The MSI and MySQL Configurator operate on all MySQL supported versions of
Windows (see
<a class="ulink" href="https://www.mysql.com/support/supportedplatforms/database.html" target="_blank">
https://www.mysql.com/support/supportedplatforms/database.html
</a>
). For
instructions on how to configure MySQL using MySQL Configurator, see
<a class="xref" href="mysql-configurator.html" title="2.3.2 Configuration: Using MySQL Configurator">
Section 2.3.2, “Configuration: Using MySQL Configurator”
</a>
.
</p>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="windows-choosing-package-no-zip">
</a>
MySQL noinstall ZIP Archives
</h4>
</div>
</div>
</div>
<p>
These packages contain the files found in the complete MySQL
Server installation package, with the exception of the GUI. This
format does not include an automated installer, but does include
MySQL Configurator to configure the MySQL server.
</p>
<p>
The
<code class="literal">
noinstall
</code>
ZIP archives are split into two
separate compressed files. The main package is named
<code class="filename">
mysql-
<em class="replaceable">
<code>
VERSION
</code>
</em>
-winx64.zip
</code>
.
This contains the components needed to use MySQL on your system.
The optional MySQL test suite, MySQL benchmark suite, and
debugging binaries/information components (including PDB files)
are in a separate compressed file named
<code class="filename">
mysql-
<em class="replaceable">
<code>
VERSION
</code>
</em>
-winx64-debug-test.zip
</code>
.
</p>
<p>
Program Database (PDB) files (with file name extension
<code class="filename">
pdb
</code>
) provide information for debugging your
MySQL installation in the event of a problem. These files are
included in ZIP Archive distributions (but not MSI
distributions) of MySQL.
</p>
<p>
To install MySQL by extracting the Zip archive rather than use
the MSI, consider the following:
</p>
<div class="orderedlist">
<ol class="orderedlist" type="1">
<li class="listitem">
<p>
If you are upgrading from a previous version please refer to
<a class="xref" href="windows-upgrading.html" title="3.11 Upgrading MySQL on Windows">
Section 3.11, “Upgrading MySQL on Windows”
</a>
, before beginning the
upgrade process.
</p>
</li>
<li class="listitem">
<p>
Make sure that you are logged in as a user with
administrator privileges.
</p>
</li>
<li class="listitem">
<p>
Choose an installation location. Traditionally, the MySQL
server is installed in
<code class="filename">
C:\mysql
</code>
. If you
do not install MySQL at
<code class="filename">
C:\mysql
</code>
, you
must specify the path to the install directory during
startup or in an option file. See
<a class="xref" href="windows-create-option-file.html" title="2.3.3.2 Creating an Option File">
Section 2.3.3.2, “Creating an Option File”
</a>
.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
The MSI installs MySQL under
<code class="filename">
C:\Program
Files\MySQL\MySQL Server 8.4\
</code>
.
</p>
</div>
</li>
<li class="listitem">
<p>
Extract the install archive to the chosen installation
location using your preferred file-compression tool. Some
tools may extract the archive to a folder within your chosen
installation location. If this occurs, you can move the
contents of the subfolder into the chosen installation
location.
</p>
</li>
<li class="listitem">
<p>
Configure the MySQL server using either MySQL Configurator
(recommended) or
<a class="xref" href="windows-install-archive.html" title="2.3.3 Configuration: Manually">
Section 2.3.3, “Configuration: Manually”
</a>
.
</p>
</li>
</ol>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="windows-choosing-package-docker">
</a>
MySQL Docker Images
</h4>
</div>
</div>
</div>
<p>
For information on using the MySQL Docker images provided by
Oracle on Windows platform, see
<a class="xref" href="deploy-mysql-nonlinux-docker.html" title="2.5.6.3 Deploying MySQL on Windows and Other Non-Linux Platforms with Docker">
Section 2.5.6.3, “Deploying MySQL on Windows and Other Non-Linux Platforms with Docker”
</a>
.
</p>
<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Warning
</div>
<p>
The MySQL Docker images provided by Oracle are built
specifically for Linux platforms. Other platforms are not
supported, and users running the MySQL Docker images from
Oracle on them are doing so at their own risk.
</p>
</div>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-online-add-node.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="mysql-cluster-online-add-node">
</a>
25.6.7 Adding NDB Cluster Data Nodes Online
</h3>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="mysql-cluster-online-add-node-remarks.html">
25.6.7.1 Adding NDB Cluster Data Nodes Online: General Issues
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="mysql-cluster-online-add-node-basics.html">
25.6.7.2 Adding NDB Cluster Data Nodes Online: Basic procedure
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="mysql-cluster-online-add-node-example.html">
25.6.7.3 Adding NDB Cluster Data Nodes Online: Detailed Example
</a>
</span>
</dt>
</dl>
</div>
<p>
This section describes how to add NDB Cluster data nodes
<span class="quote">
“
<span class="quote">
online
</span>
”
</span>
—that is, without needing to shut down
the cluster completely and restart it as part of the process.
</p>
<div class="important" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Important
</div>
<p>
Currently, you must add new data nodes to an NDB Cluster as part
of a new node group. In addition, it is not possible to change
the number of fragment replicas (or the number of nodes per node
group) online.
</p>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/grant-tables.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="grant-tables">
</a>
8.2.3 Grant Tables
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045250727184">
</a>
<a class="indexterm" name="idm46045250725696">
</a>
<p>
The
<code class="literal">
mysql
</code>
system database includes several
grant tables that contain information about user accounts and the
privileges held by them. This section describes those tables. For
information about other tables in the system database, see
<a class="xref" href="system-schema.html" title="7.3 The mysql System Schema">
Section 7.3, “The mysql System Schema”
</a>
.
</p>
<p>
The discussion here describes the underlying structure of the
grant tables and how the server uses their contents when
interacting with clients. However, normally you do not modify the
grant tables directly. Modifications occur indirectly when you use
account-management statements such as
<a class="link" href="create-user.html" title="15.7.1.3 CREATE USER Statement">
<code class="literal">
CREATE
USER
</code>
</a>
,
<a class="link" href="grant.html" title="15.7.1.6 GRANT Statement">
<code class="literal">
GRANT
</code>
</a>
, and
<a class="link" href="revoke.html" title="15.7.1.8 REVOKE Statement">
<code class="literal">
REVOKE
</code>
</a>
to set up accounts and
control the privileges available to each one. See
<a class="xref" href="account-management-statements.html" title="15.7.1 Account Management Statements">
Section 15.7.1, “Account Management Statements”
</a>
. When you use such
statements to perform account manipulations, the server modifies
the grant tables on your behalf.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
Direct modification of grant tables using statements such as
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
,
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
, or
<a class="link" href="delete.html" title="15.2.2 DELETE Statement">
<code class="literal">
DELETE
</code>
</a>
is discouraged and done at
your own risk. The server is free to ignore rows that become
malformed as a result of such modifications.
</p>
<p>
For any operation that modifies a grant table, the server checks
whether the table has the expected structure and produces an
error if not. To update the tables to the expected structure,
perform the MySQL upgrade procedure. See
<a class="xref" href="upgrading.html" title="Chapter 3 Upgrading MySQL">
Chapter 3,
<i>
Upgrading MySQL
</i>
</a>
.
</p>
</div>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="xref" href="grant-tables.html#grant-tables-overview" title="Grant Table Overview">
Grant Table Overview
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="grant-tables.html#grant-tables-user-db" title="The user and db Grant Tables">
The user and db Grant Tables
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="grant-tables.html#grant-tables-tables-priv-columns-priv" title="The tables_priv and columns_priv Grant Tables">
The tables_priv and columns_priv Grant Tables
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="grant-tables.html#grant-tables-procs-priv" title="The procs_priv Grant Table">
The procs_priv Grant Table
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="grant-tables.html#grant-tables-proxies-priv" title="The proxies_priv Grant Table">
The proxies_priv Grant Table
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="grant-tables.html#grant-tables-global-grants" title="The global_grants Grant Table">
The global_grants Grant Table
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="grant-tables.html#grant-tables-default-roles" title="The default_roles Grant Table">
The default_roles Grant Table
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="grant-tables.html#grant-tables-role-edges" title="The role_edges Grant Table">
The role_edges Grant Table
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="grant-tables.html#grant-tables-password-history" title="The password_history Grant Table">
The password_history Grant Table
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="grant-tables.html#grant-tables-scope-column-properties" title="Grant Table Scope Column Properties">
Grant Table Scope Column Properties
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="grant-tables.html#grant-tables-privilege-column-properties" title="Grant Table Privilege Column Properties">
Grant Table Privilege Column Properties
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="grant-tables.html#grant-tables-concurrency" title="Grant Table Concurrency">
Grant Table Concurrency
</a>
</p>
</li>
</ul>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="grant-tables-overview">
</a>
Grant Table Overview
</h4>
</div>
</div>
</div>
<p>
These
<code class="literal">
mysql
</code>
database tables contain grant
information:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="link" href="grant-tables.html#grant-tables-user-db" title="The user and db Grant Tables">
<code class="literal">
user
</code>
</a>
:
User accounts, static global privileges, and other
nonprivilege columns.
</p>
<a class="indexterm" name="idm46045250693312">
</a>
<a class="indexterm" name="idm46045250691824">
</a>
<a class="indexterm" name="idm46045250690336">
</a>
</li>
<li class="listitem">
<p>
<a class="link" href="grant-tables.html#grant-tables-global-grants" title="The global_grants Grant Table">
<code class="literal">
global_grants
</code>
</a>
:
Dynamic global privileges.
</p>
<a class="indexterm" name="idm46045250686736">
</a>
<a class="indexterm" name="idm46045250685248">
</a>
<a class="indexterm" name="idm46045250683760">
</a>
</li>
<li class="listitem">
<p>
<a class="link" href="grant-tables.html#grant-tables-user-db" title="The user and db Grant Tables">
<code class="literal">
db
</code>
</a>
:
Database-level privileges.
</p>
<a class="indexterm" name="idm46045250680320">
</a>
<a class="indexterm" name="idm46045250678832">
</a>
<a class="indexterm" name="idm46045250677344">
</a>
</li>
<li class="listitem">
<p>
<a class="link" href="grant-tables.html#grant-tables-tables-priv-columns-priv" title="The tables_priv and columns_priv Grant Tables">
<code class="literal">
tables_priv
</code>
</a>
:
Table-level privileges.
</p>
<a class="indexterm" name="idm46045250673744">
</a>
<a class="indexterm" name="idm46045250672256">
</a>
<a class="indexterm" name="idm46045250670768">
</a>
</li>
<li class="listitem">
<p>
<a class="link" href="grant-tables.html#grant-tables-tables-priv-columns-priv" title="The tables_priv and columns_priv Grant Tables">
<code class="literal">
columns_priv
</code>
</a>
:
Column-level privileges.
</p>
<a class="indexterm" name="idm46045250667216">
</a>
<a class="indexterm" name="idm46045250665728">
</a>
<a class="indexterm" name="idm46045250664240">
</a>
</li>
<li class="listitem">
<p>
<a class="link" href="grant-tables.html#grant-tables-procs-priv" title="The procs_priv Grant Table">
<code class="literal">
procs_priv
</code>
</a>
:
Stored procedure and function privileges.
</p>
<a class="indexterm" name="idm46045250660752">
</a>
<a class="indexterm" name="idm46045250659264">
</a>
<a class="indexterm" name="idm46045250657776">
</a>
</li>
<li class="listitem">
<p>
<a class="link" href="grant-tables.html#grant-tables-proxies-priv" title="The proxies_priv Grant Table">
<code class="literal">
proxies_priv
</code>
</a>
:
Proxy-user privileges.
</p>
<a class="indexterm" name="idm46045250654176">
</a>
<a class="indexterm" name="idm46045250652688">
</a>
<a class="indexterm" name="idm46045250651200">
</a>
</li>
<li class="listitem">
<p>
<a class="link" href="grant-tables.html#grant-tables-default-roles" title="The default_roles Grant Table">
<code class="literal">
default_roles
</code>
</a>
:
Default user roles.
</p>
<a class="indexterm" name="idm46045250647648">
</a>
<a class="indexterm" name="idm46045250646160">
</a>
<a class="indexterm" name="idm46045250644672">
</a>
</li>
<li class="listitem">
<p>
<a class="link" href="grant-tables.html#grant-tables-role-edges" title="The role_edges Grant Table">
<code class="literal">
role_edges
</code>
</a>
:
Edges for role subgraphs.
</p>
<a class="indexterm" name="idm46045250641200">
</a>
<a class="indexterm" name="idm46045250639712">
</a>
<a class="indexterm" name="idm46045250638224">
</a>
</li>
<li class="listitem">
<p>
<a class="link" href="grant-tables.html#grant-tables-password-history" title="The password_history Grant Table">
<code class="literal">
password_history
</code>
</a>
:
Password change history.
</p>
<a class="indexterm" name="idm46045250634624">
</a>
<a class="indexterm" name="idm46045250633136">
</a>
<a class="indexterm" name="idm46045250631648">
</a>
</li>
</ul>
</div>
<p>
For information about the differences between static and dynamic
global privileges, see
<a class="xref" href="privileges-provided.html#static-dynamic-privileges" title="Static Versus Dynamic Privileges">
Static Versus Dynamic Privileges
</a>
.)
</p>
<p>
In MySQL 8.4, grant tables use the
<code class="literal">
InnoDB
</code>
storage engine and are transactional.
Before MySQL 8.4, grant tables used the
<code class="literal">
MyISAM
</code>
storage engine and were
nontransactional. This change of grant table storage engine
enables an accompanying change to the behavior of
account-management statements such as
<a class="link" href="create-user.html" title="15.7.1.3 CREATE USER Statement">
<code class="literal">
CREATE USER
</code>
</a>
or
<a class="link" href="grant.html" title="15.7.1.6 GRANT Statement">
<code class="literal">
GRANT
</code>
</a>
. Previously, an
account-management statement that named multiple users could
succeed for some users and fail for others. Now, each statement
is transactional and either succeeds for all named users or
rolls back and has no effect if any error occurs.
</p>
<p>
Each grant table contains scope columns and privilege columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Scope columns determine the scope of each row in the tables;
that is, the context in which the row applies. For example,
a
<code class="literal">
user
</code>
table row with
<code class="literal">
Host
</code>
and
<code class="literal">
User
</code>
values
of
<code class="literal">
'h1.example.net'
</code>
and
<code class="literal">
'bob'
</code>
applies to authenticating
connections made to the server from the host
<code class="literal">
h1.example.net
</code>
by a client that specifies
a user name of
<code class="literal">
bob
</code>
. Similarly, a
<code class="literal">
db
</code>
table row with
<code class="literal">
Host
</code>
,
<code class="literal">
User
</code>
, and
<code class="literal">
Db
</code>
column values of
<code class="literal">
'h1.example.net'
</code>
,
<code class="literal">
'bob'
</code>
and
<code class="literal">
'reports'
</code>
applies when
<code class="literal">
bob
</code>
connects from the host
<code class="literal">
h1.example.net
</code>
to access the
<code class="literal">
reports
</code>
database. The
<code class="literal">
tables_priv
</code>
and
<code class="literal">
columns_priv
</code>
tables contain scope columns
indicating tables or table/column combinations to which each
row applies. The
<code class="literal">
procs_priv
</code>
scope columns
indicate the stored routine to which each row applies.
</p>
</li>
<li class="listitem">
<p>
Privilege columns indicate which privileges a table row
grants; that is, which operations it permits to be
performed. The server combines the information in the
various grant tables to form a complete description of a
user's privileges.
<a class="xref" href="request-access.html" title="8.2.7 Access Control, Stage 2: Request Verification">
Section 8.2.7, “Access Control, Stage 2: Request Verification”
</a>
,
describes the rules for this.
</p>
</li>
</ul>
</div>
<p>
In addition, a grant table may contain columns used for purposes
other than scope or privilege assessment.
</p>
<p>
The server uses the grant tables in the following manner:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
The
<code class="literal">
user
</code>
table scope columns determine
whether to reject or permit incoming connections. For
permitted connections, any privileges granted in the
<code class="literal">
user
</code>
table indicate the user's static
global privileges. Any privileges granted in this table
apply to
<span class="emphasis">
<em>
all
</em>
</span>
databases on the server.
</p>
<div class="caution" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Caution
</div>
<p>
Because any static global privilege is considered a
privilege for all databases, any static global privilege
enables a user to see all database names with
<a class="link" href="show-databases.html" title="15.7.7.15 SHOW DATABASES Statement">
<code class="literal">
SHOW DATABASES
</code>
</a>
or by
examining the
<a class="link" href="information-schema-schemata-table.html" title="28.3.31 The INFORMATION_SCHEMA SCHEMATA Table">
<code class="literal">
SCHEMATA
</code>
</a>
table
of
<code class="literal">
INFORMATION_SCHEMA
</code>
, except databases
that have been restricted at the database level by partial
revokes.
</p>
</div>
</li>
<li class="listitem">
<p>
The
<code class="literal">
global_grants
</code>
table lists current
assignments of dynamic global privileges to user accounts.
For each row, the scope columns determine which user has the
privilege named in the privilege column.
</p>
</li>
<li class="listitem">
<p>
The
<code class="literal">
db
</code>
table scope columns determine
which users can access which databases from which hosts. The
privilege columns determine the permitted operations. A
privilege granted at the database level applies to the
database and to all objects in the database, such as tables
and stored programs.
</p>
</li>
<li class="listitem">
<p>
The
<code class="literal">
tables_priv
</code>
and
<code class="literal">
columns_priv
</code>
tables are similar to the
<code class="literal">
db
</code>
table, but are more fine-grained: They
apply at the table and column levels rather than at the
database level. A privilege granted at the table level
applies to the table and to all its columns. A privilege
granted at the column level applies only to a specific
column.
</p>
</li>
<li class="listitem">
<p>
The
<code class="literal">
procs_priv
</code>
table applies to stored
routines (stored procedures and functions). A privilege
granted at the routine level applies only to a single
procedure or function.
</p>
</li>
<li class="listitem">
<p>
The
<code class="literal">
proxies_priv
</code>
table indicates which
users can act as proxies for other users and whether a user
can grant the
<a class="link" href="privileges-provided.html#priv_proxy">
<code class="literal">
PROXY
</code>
</a>
privilege
to other users.
</p>
</li>
<li class="listitem">
<p>
The
<code class="literal">
default_roles
</code>
and
<code class="literal">
role_edges
</code>
tables contain information
about role relationships.
</p>
</li>
<li class="listitem">
<p>
The
<code class="literal">
password_history
</code>
table retains
previously chosen passwords to enable restrictions on
password reuse. See
<a class="xref" href="password-management.html" title="8.2.15 Password Management">
Section 8.2.15, “Password Management”
</a>
.
</p>
</li>
</ul>
</div>
<p>
The server reads the contents of the grant tables into memory
when it starts. You can tell it to reload the tables by issuing
a
<a class="link" href="flush.html#flush-privileges">
<code class="literal">
FLUSH PRIVILEGES
</code>
</a>
statement or
executing a
<a class="link" href="mysqladmin.html" title="6.5.2 mysqladmin — A MySQL Server Administration Program">
<span class="command">
<strong>
mysqladmin flush-privileges
</strong>
</span>
</a>
or
<a class="link" href="mysqladmin.html" title="6.5.2 mysqladmin — A MySQL Server Administration Program">
<span class="command">
<strong>
mysqladmin reload
</strong>
</span>
</a>
command. Changes to the
grant tables take effect as indicated in
<a class="xref" href="privilege-changes.html" title="8.2.13 When Privilege Changes Take Effect">
Section 8.2.13, “When Privilege Changes Take Effect”
</a>
.
</p>
<p>
When you modify an account, it is a good idea to verify that
your changes have the intended effect. To check the privileges
for a given account, use the
<a class="link" href="show-grants.html" title="15.7.7.22 SHOW GRANTS Statement">
<code class="literal">
SHOW
GRANTS
</code>
</a>
statement. For example, to determine the
privileges that are granted to an account with user name and
host name values of
<code class="literal">
bob
</code>
and
<code class="literal">
pc84.example.com
</code>
, use this statement:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa47206099"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SHOW</span> <span class="token keyword">GRANTS</span> <span class="token keyword">FOR</span> <span class="token string">'bob'</span>@<span class="token string">'pc84.example.com'</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
To display nonprivilege properties of an account, use
<a class="link" href="show-create-user.html" title="15.7.7.13 SHOW CREATE USER Statement">
<code class="literal">
SHOW CREATE USER
</code>
</a>
:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa89663300"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SHOW</span> <span class="token keyword">CREATE</span> <span class="token keyword">USER</span> <span class="token string">'bob'</span>@<span class="token string">'pc84.example.com'</span><span class="token punctuation">;</span></code></pre>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="grant-tables-user-db">
</a>
The user and db Grant Tables
</h4>
</div>
</div>
</div>
<p>
The server uses the
<code class="literal">
user
</code>
and
<code class="literal">
db
</code>
tables in the
<code class="literal">
mysql
</code>
database at both the first and second stages of access control
(see
<a class="xref" href="access-control.html" title="8.2 Access Control and Account Management">
Section 8.2, “Access Control and Account Management”
</a>
). The columns in the
<code class="literal">
user
</code>
and
<code class="literal">
db
</code>
tables are
shown here.
</p>
<div class="table">
<a name="idm46045250562832">
</a>
<p class="title">
<b>
Table 8.4 user and db Table Columns
</b>
</p>
<div class="table-contents">
<table>
<colgroup>
<col style="width: 40%"/>
<col style="width: 30%"/>
<col style="width: 30%"/>
</colgroup>
<thead>
<tr>
<th scope="col">
Table Name
</th>
<th scope="col">
<code class="literal">
user
</code>
</th>
<th scope="col">
<code class="literal">
db
</code>
</th>
</tr>
</thead>
<tbody>
<tr>
<th scope="row">
<span class="bold">
<strong>
Scope columns
</strong>
</span>
</th>
<td>
<code class="literal">
Host
</code>
</td>
<td>
<code class="literal">
Host
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
User
</code>
</td>
<td>
<code class="literal">
Db
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
</td>
<td>
<code class="literal">
User
</code>
</td>
</tr>
<tr>
<th scope="row">
<span class="bold">
<strong>
Privilege columns
</strong>
</span>
</th>
<td>
<code class="literal">
Select_priv
</code>
</td>
<td>
<code class="literal">
Select_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Insert_priv
</code>
</td>
<td>
<code class="literal">
Insert_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Update_priv
</code>
</td>
<td>
<code class="literal">
Update_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Delete_priv
</code>
</td>
<td>
<code class="literal">
Delete_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Index_priv
</code>
</td>
<td>
<code class="literal">
Index_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Alter_priv
</code>
</td>
<td>
<code class="literal">
Alter_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Create_priv
</code>
</td>
<td>
<code class="literal">
Create_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Drop_priv
</code>
</td>
<td>
<code class="literal">
Drop_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Grant_priv
</code>
</td>
<td>
<code class="literal">
Grant_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Create_view_priv
</code>
</td>
<td>
<code class="literal">
Create_view_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Show_view_priv
</code>
</td>
<td>
<code class="literal">
Show_view_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Create_routine_priv
</code>
</td>
<td>
<code class="literal">
Create_routine_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Alter_routine_priv
</code>
</td>
<td>
<code class="literal">
Alter_routine_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Execute_priv
</code>
</td>
<td>
<code class="literal">
Execute_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Trigger_priv
</code>
</td>
<td>
<code class="literal">
Trigger_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Event_priv
</code>
</td>
<td>
<code class="literal">
Event_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Create_tmp_table_priv
</code>
</td>
<td>
<code class="literal">
Create_tmp_table_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Lock_tables_priv
</code>
</td>
<td>
<code class="literal">
Lock_tables_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
References_priv
</code>
</td>
<td>
<code class="literal">
References_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Reload_priv
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Shutdown_priv
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Process_priv
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
File_priv
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Show_db_priv
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Super_priv
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Repl_slave_priv
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Repl_client_priv
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Create_user_priv
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Create_tablespace_priv
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Create_role_priv
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Drop_role_priv
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<span class="bold">
<strong>
Security columns
</strong>
</span>
</th>
<td>
<code class="literal">
ssl_type
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
ssl_cipher
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
x509_issuer
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
x509_subject
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
plugin
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
authentication_string
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
password_expired
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
password_last_changed
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
password_lifetime
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
account_locked
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Password_reuse_history
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Password_reuse_time
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Password_require_current
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
User_attributes
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<span class="bold">
<strong>
Resource control columns
</strong>
</span>
</th>
<td>
<code class="literal">
max_questions
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
max_updates
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
max_connections
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
max_user_connections
</code>
</td>
<td>
</td>
</tr>
</tbody>
</table>
</div>
<div class="table-contents">
<table cellpadding="0" cellspacing="0" style="position: fixed; top: 0px; display: none; left: 401px; width: 674px;">
<thead>
<tr>
<th scope="col" style="width: 269.344px;">
Table Name
</th>
<th scope="col" style="width: 202.016px;">
<code class="literal">
user
</code>
</th>
<th scope="col" style="width: 202.016px;">
<code class="literal">
db
</code>
</th>
</tr>
</thead>
</table>
</div>
</div>
<br class="table-break"/>
<p>
The
<code class="literal">
user
</code>
table
<code class="literal">
plugin
</code>
and
<code class="literal">
authentication_string
</code>
columns store
authentication plugin and credential information.
</p>
<p>
The server uses the plugin named in the
<code class="literal">
plugin
</code>
column of an account row to
authenticate connection attempts for the account.
</p>
<p>
The
<code class="literal">
plugin
</code>
column must be nonempty. At
startup, and at runtime when
<a class="link" href="flush.html#flush-privileges">
<code class="literal">
FLUSH
PRIVILEGES
</code>
</a>
is executed, the server checks
<code class="literal">
user
</code>
table rows. For any row with an empty
<code class="literal">
plugin
</code>
column, the server writes a warning to
the error log of this form:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-none"><div class="docs-select-all right" id="sa84403984"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-none">[Warning] User entry '<em class="replaceable">user_name</em>'@'<em class="replaceable">host_name</em>' has an empty plugin
value. The user will be ignored and no one can login with this user
anymore.</code></pre>
</div>
<p>
To assign a plugin to an account that is missing one, use the
<a class="link" href="alter-user.html" title="15.7.1.1 ALTER USER Statement">
<code class="literal">
ALTER USER
</code>
</a>
statement.
</p>
<p>
The
<code class="literal">
password_expired
</code>
column permits DBAs to
expire account passwords and require users to reset their
password. The default
<code class="literal">
password_expired
</code>
value
is
<code class="literal">
'N'
</code>
, but can be set to
<code class="literal">
'Y'
</code>
with the
<a class="link" href="alter-user.html" title="15.7.1.1 ALTER USER Statement">
<code class="literal">
ALTER
USER
</code>
</a>
statement. After an account's password has been
expired, all operations performed by the account in subsequent
connections to the server result in an error until the user
issues an
<a class="link" href="alter-user.html" title="15.7.1.1 ALTER USER Statement">
<code class="literal">
ALTER USER
</code>
</a>
statement to
establish a new account password.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
Although it is possible to
<span class="quote">
“
<span class="quote">
reset
</span>
”
</span>
an expired
password by setting it to its current value, it is preferable,
as a matter of good policy, to choose a different password.
DBAs can enforce non-reuse by establishing an appropriate
password-reuse policy. See
<a class="xref" href="password-management.html#password-reuse-policy" title="Password Reuse Policy">
Password Reuse Policy
</a>
.
</p>
</div>
<p>
<code class="literal">
password_last_changed
</code>
is a
<code class="literal">
TIMESTAMP
</code>
column indicating when the password
was last changed. The value is non-
<code class="literal">
NULL
</code>
only
for accounts that use a MySQL built-in authentication plugin
(
<code class="literal">
mysql_native_password
</code>
which is deprecated,
<code class="literal">
sha256_password
</code>
which is deprecated, or
<code class="literal">
caching_sha2_password
</code>
). The value is
<code class="literal">
NULL
</code>
for other accounts, such as those
authenticated using an external authentication system.
</p>
<p>
<code class="literal">
password_last_changed
</code>
is updated by the
<a class="link" href="create-user.html" title="15.7.1.3 CREATE USER Statement">
<code class="literal">
CREATE USER
</code>
</a>
,
<a class="link" href="alter-user.html" title="15.7.1.1 ALTER USER Statement">
<code class="literal">
ALTER USER
</code>
</a>
, and
<a class="link" href="set-password.html" title="15.7.1.10 SET PASSWORD Statement">
<code class="literal">
SET PASSWORD
</code>
</a>
statements, and by
<a class="link" href="grant.html" title="15.7.1.6 GRANT Statement">
<code class="literal">
GRANT
</code>
</a>
statements that create an
account or change an account password.
</p>
<p>
<code class="literal">
password_lifetime
</code>
indicates the account
password lifetime, in days. If the password is past its lifetime
(assessed using the
<code class="literal">
password_last_changed
</code>
column), the server considers the password expired when clients
connect using the account. A value of
<em class="replaceable">
<code>
N
</code>
</em>
greater than zero means that the
password must be changed every
<em class="replaceable">
<code>
N
</code>
</em>
days. A value of 0 disables automatic password expiration. If
the value is
<code class="literal">
NULL
</code>
(the default), the global
expiration policy applies, as defined by the
<a class="link" href="server-system-variables.html#sysvar_default_password_lifetime">
<code class="literal">
default_password_lifetime
</code>
</a>
system variable.
</p>
<a class="indexterm" name="idm46045250327056">
</a>
<a class="indexterm" name="idm46045250325984">
</a>
<a class="indexterm" name="idm46045250324496">
</a>
<p>
<code class="literal">
account_locked
</code>
indicates whether the account
is locked (see
<a class="xref" href="account-locking.html" title="8.2.20 Account Locking">
Section 8.2.20, “Account Locking”
</a>
).
</p>
<p>
<code class="literal">
Password_reuse_history
</code>
is the value of the
<code class="literal">
PASSWORD HISTORY
</code>
option for the account, or
<code class="literal">
NULL
</code>
for the default history.
</p>
<p>
<code class="literal">
Password_reuse_time
</code>
is the value of the
<code class="literal">
PASSWORD REUSE INTERVAL
</code>
option for the
account, or
<code class="literal">
NULL
</code>
for the default interval.
</p>
<p>
<code class="literal">
Password_require_current
</code>
corresponds to the
value of the
<code class="literal">
PASSWORD REQUIRE
</code>
option for the
account, as shown by the following table.
</p>
<div class="table">
<a name="password-require-current-values-table">
</a>
<p class="title">
<b>
Table 8.5 Permitted Password_require_current Values
</b>
</p>
<div class="table-contents">
<table summary="Permitted values of the user.Password_require_current column and how they correspond to PASSWORD REQUIRE options.">
<colgroup>
<col style="width: 50%"/>
<col style="width: 50%"/>
</colgroup>
<thead>
<tr>
<th>
Password_require_current Value
</th>
<th>
Corresponding PASSWORD REQUIRE Option
</th>
</tr>
</thead>
<tbody>
<tr>
<td>
<code class="literal">
'Y'
</code>
</td>
<td>
<code class="literal">
PASSWORD REQUIRE CURRENT
</code>
</td>
</tr>
<tr>
<td>
<code class="literal">
'N'
</code>
</td>
<td>
<code class="literal">
PASSWORD REQUIRE CURRENT OPTIONAL
</code>
</td>
</tr>
<tr>
<td>
<code class="literal">
NULL
</code>
</td>
<td>
<code class="literal">
PASSWORD REQUIRE CURRENT DEFAULT
</code>
</td>
</tr>
</tbody>
</table>
</div>
</div>
<br class="table-break"/>
<p>
<code class="literal">
User_attributes
</code>
is a JSON-format column that
stores account attributes not stored in other columns. The
<code class="literal">
INFORMATION_SCHEMA
</code>
exposes these attributes
through the
<a class="link" href="information-schema-user-attributes-table.html" title="28.3.45 The INFORMATION_SCHEMA USER_ATTRIBUTES Table">
<code class="literal">
USER_ATTRIBUTES
</code>
</a>
table.
</p>
<p>
The
<code class="literal">
User_attributes
</code>
column may contain these
attributes:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
additional_password
</code>
: The secondary
password, if any. See
<a class="xref" href="password-management.html#dual-passwords" title="Dual Password Support">
Dual Password Support
</a>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Restrictions
</code>
: Restriction lists, if any.
Restrictions are added by partial-revoke operations. The
attribute value is an array of elements that each have
<code class="literal">
Database
</code>
and
<code class="literal">
Restrictions
</code>
keys indicating the name of
a restricted database and the applicable restrictions on it
(see
<a class="xref" href="partial-revokes.html" title="8.2.12 Privilege Restriction Using Partial Revokes">
Section 8.2.12, “Privilege Restriction Using Partial Revokes”
</a>
).
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Password_locking
</code>
: The conditions for
failed-login tracking and temporary account locking, if any
(see
<a class="xref" href="password-management.html#failed-login-tracking" title="Failed-Login Tracking and Temporary Account Locking">
Failed-Login Tracking and Temporary Account Locking
</a>
). The
<code class="literal">
Password_locking
</code>
attribute is updated
according to the
<code class="literal">
FAILED_LOGIN_ATTEMPTS
</code>
and
<code class="literal">
PASSWORD_LOCK_TIME
</code>
options of the
<a class="link" href="create-user.html" title="15.7.1.3 CREATE USER Statement">
<code class="literal">
CREATE USER
</code>
</a>
and
<a class="link" href="alter-user.html" title="15.7.1.1 ALTER USER Statement">
<code class="literal">
ALTER USER
</code>
</a>
statements. The
attribute value is a hash with
<code class="literal">
failed_login_attempts
</code>
and
<code class="literal">
password_lock_time_days
</code>
keys indicating
the value of such options as have been specified for the
account. If a key is missing, its value is implicitly 0. If
a key value is implicitly or explicitly 0, the corresponding
capability is disabled.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
multi_factor_authentication
</code>
: Rows in the
<code class="literal">
mysql.user
</code>
system table have a
<code class="literal">
plugin
</code>
column that indicates an
authentication plugin. For single-factor authentication,
that plugin is the only authentication factor. For
two-factor or three-factor forms of multifactor
authentication, that plugin corresponds to the first
authentication factor, but additional information must be
stored for the second and third factors. The
<code class="literal">
multi_factor_authentication
</code>
attribute
holds this information.
</p>
<p>
The
<code class="literal">
multi_factor_authentication
</code>
value is
an array, where each array element is a hash that describes
an authentication factor using these attributes:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
<code class="literal">
plugin
</code>
: The name of the
authentication plugin.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
authentication_string
</code>
: The
authentication string value.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
passwordless
</code>
: A flag that denotes
whether the user is meant to be used without a password
(with a security token as the only authentication
method).
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
requires_registration
</code>
: a flag that
defines whether the user account has registered a
security token.
</p>
</li>
</ul>
</div>
<p>
The first and second array elements describe multifactor
authentication factors 2 and 3.
</p>
</li>
</ul>
</div>
<p>
If no attributes apply,
<code class="literal">
User_attributes
</code>
is
<code class="literal">
NULL
</code>
.
</p>
<p>
Example: An account that has a secondary password and partially
revoked database privileges has
<code class="literal">
additional_password
</code>
and
<code class="literal">
Restrictions
</code>
attributes in the column value:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa55129394"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> User_attributes <span class="token keyword">FROM</span> mysql<span class="token punctuation">.</span><span class="token keyword">User</span> <span class="token keyword">WHERE</span> <span class="token keyword">User</span> <span class="token operator">=</span> <span class="token string">'u'</span>\G
<span class="token output"><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span> 1. row <span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span>
User_attributes<span class="token punctuation">:</span> {"Restrictions"<span class="token punctuation">:</span>
[{"Database"<span class="token punctuation">:</span> "mysql", "Privileges"<span class="token punctuation">:</span> ["SELECT"]}],
"additional_password"<span class="token punctuation">:</span> "<em class="replaceable">hashed_credentials</em>"}</span></code></pre>
</div>
<p>
To determine which attributes are present, use the
<a class="link" href="json-search-functions.html#function_json-keys">
<code class="literal">
JSON_KEYS()
</code>
</a>
function:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa36367215"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token keyword">User</span><span class="token punctuation">,</span> <span class="token keyword">Host</span><span class="token punctuation">,</span> <span class="token function">JSON_KEYS</span><span class="token punctuation">(</span>User_attributes<span class="token punctuation">)</span>
<span class="token keyword">FROM</span> mysql<span class="token punctuation">.</span><span class="token keyword">user</span> <span class="token keyword">WHERE</span> User_attributes <span class="token operator">IS</span> <span class="token operator">NOT</span> <span class="token boolean">NULL</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
To extract a particular attribute, such as
<code class="literal">
Restrictions
</code>
, do this:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa25013096"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> <span class="token keyword">User</span><span class="token punctuation">,</span> <span class="token keyword">Host</span><span class="token punctuation">,</span> User_attributes<span class="token operator">-</span><span class="token operator">>></span><span class="token string">'$.Restrictions'</span>
<span class="token keyword">FROM</span> mysql<span class="token punctuation">.</span><span class="token keyword">user</span> <span class="token keyword">WHERE</span> User_attributes<span class="token operator">-</span><span class="token operator">>></span><span class="token string">'$.Restrictions'</span> <span class="token operator"><></span> <span class="token string">''</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
Here is an example of the kind of information stored for
<code class="literal">
multi_factor_authentication
</code>
:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-json"><div class="docs-select-all right" id="sa154998"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-json"><span class="token punctuation">{</span>
<span class="token property">"multi_factor_authentication"</span><span class="token operator">:</span> <span class="token punctuation">[</span>
<span class="token punctuation">{</span>
<span class="token property">"plugin"</span><span class="token operator">:</span> <span class="token string">"authentication_ldap_simple"</span><span class="token punctuation">,</span>
<span class="token property">"passwordless"</span><span class="token operator">:</span> <span class="token number">0</span><span class="token punctuation">,</span>
<span class="token property">"authentication_string"</span><span class="token operator">:</span> <span class="token string">"ldap auth string"</span><span class="token punctuation">,</span>
<span class="token property">"requires_registration"</span><span class="token operator">:</span> <span class="token number">0</span>
<span class="token punctuation">}</span><span class="token punctuation">,</span>
<span class="token punctuation">{</span>
<span class="token property">"plugin"</span><span class="token operator">:</span> <span class="token string">"authentication_webauthn"</span><span class="token punctuation">,</span>
<span class="token property">"passwordless"</span><span class="token operator">:</span> <span class="token number">0</span><span class="token punctuation">,</span>
<span class="token property">"authentication_string"</span><span class="token operator">:</span> <span class="token string">""</span><span class="token punctuation">,</span>
<span class="token property">"requires_registration"</span><span class="token operator">:</span> <span class="token number">1</span>
<span class="token punctuation">}</span>
<span class="token punctuation">]</span>
<span class="token punctuation">}</span></code></pre>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="grant-tables-tables-priv-columns-priv">
</a>
The tables_priv and columns_priv Grant Tables
</h4>
</div>
</div>
</div>
<p>
During the second stage of access control, the server performs
request verification to ensure that each client has sufficient
privileges for each request that it issues. In addition to the
<code class="literal">
user
</code>
and
<code class="literal">
db
</code>
grant tables,
the server may also consult the
<code class="literal">
tables_priv
</code>
and
<code class="literal">
columns_priv
</code>
tables for requests that
involve tables. The latter tables provide finer privilege
control at the table and column levels. They have the columns
shown in the following table.
</p>
<div class="table">
<a name="idm46045250247296">
</a>
<p class="title">
<b>
Table 8.6 tables_priv and columns_priv Table Columns
</b>
</p>
<div class="table-contents">
<table>
<colgroup>
<col style="width: 20%"/>
<col style="width: 20%"/>
<col style="width: 20%"/>
</colgroup>
<thead>
<tr>
<th scope="col">
Table Name
</th>
<th scope="col">
<code class="literal">
tables_priv
</code>
</th>
<th scope="col">
<code class="literal">
columns_priv
</code>
</th>
</tr>
</thead>
<tbody>
<tr>
<th scope="row">
<span class="bold">
<strong>
Scope columns
</strong>
</span>
</th>
<td>
<code class="literal">
Host
</code>
</td>
<td>
<code class="literal">
Host
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Db
</code>
</td>
<td>
<code class="literal">
Db
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
User
</code>
</td>
<td>
<code class="literal">
User
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Table_name
</code>
</td>
<td>
<code class="literal">
Table_name
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
</td>
<td>
<code class="literal">
Column_name
</code>
</td>
</tr>
<tr>
<th scope="row">
<span class="bold">
<strong>
Privilege columns
</strong>
</span>
</th>
<td>
<code class="literal">
Table_priv
</code>
</td>
<td>
<code class="literal">
Column_priv
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Column_priv
</code>
</td>
<td>
</td>
</tr>
<tr>
<th scope="row">
<span class="bold">
<strong>
Other columns
</strong>
</span>
</th>
<td>
<code class="literal">
Timestamp
</code>
</td>
<td>
<code class="literal">
Timestamp
</code>
</td>
</tr>
<tr>
<th scope="row">
</th>
<td>
<code class="literal">
Grantor
</code>
</td>
<td>
</td>
</tr>
</tbody>
</table>
</div>
</div>
<br class="table-break"/>
<p>
The
<code class="literal">
Timestamp
</code>
and
<code class="literal">
Grantor
</code>
columns are set to the current timestamp and the
<a class="link" href="information-functions.html#function_current-user">
<code class="literal">
CURRENT_USER
</code>
</a>
value, respectively,
but are otherwise unused.
</p>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="grant-tables-procs-priv">
</a>
The procs_priv Grant Table
</h4>
</div>
</div>
</div>
<p>
For verification of requests that involve stored routines, the
server may consult the
<code class="literal">
procs_priv
</code>
table,
which has the columns shown in the following table.
</p>
<div class="table">
<a name="idm46045250197632">
</a>
<p class="title">
<b>
Table 8.7 procs_priv Table Columns
</b>
</p>
<div class="table-contents">
<table>
<colgroup>
<col style="width: 20%"/>
<col style="width: 20%"/>
</colgroup>
<thead>
<tr>
<th>
Table Name
</th>
<th>
<code class="literal">
procs_priv
</code>
</th>
</tr>
</thead>
<tbody>
<tr>
<td>
<span class="bold">
<strong>
Scope columns
</strong>
</span>
</td>
<td>
<code class="literal">
Host
</code>
</td>
</tr>
<tr>
<td>
</td>
<td>
<code class="literal">
Db
</code>
</td>
</tr>
<tr>
<td>
</td>
<td>
<code class="literal">
User
</code>
</td>
</tr>
<tr>
<td>
</td>
<td>
<code class="literal">
Routine_name
</code>
</td>
</tr>
<tr>
<td>
</td>
<td>
<code class="literal">
Routine_type
</code>
</td>
</tr>
<tr>
<td>
<span class="bold">
<strong>
Privilege columns
</strong>
</span>
</td>
<td>
<code class="literal">
Proc_priv
</code>
</td>
</tr>
<tr>
<td>
<span class="bold">
<strong>
Other columns
</strong>
</span>
</td>
<td>
<code class="literal">
Timestamp
</code>
</td>
</tr>
<tr>
<td>
</td>
<td>
<code class="literal">
Grantor
</code>
</td>
</tr>
</tbody>
</table>
</div>
</div>
<br class="table-break"/>
<p>
The
<code class="literal">
Routine_type
</code>
column is an
<a class="link" href="enum.html" title="13.3.5 The ENUM Type">
<code class="literal">
ENUM
</code>
</a>
column with values of
<code class="literal">
'FUNCTION'
</code>
or
<code class="literal">
'PROCEDURE'
</code>
to indicate the type of routine the row refers to. This column
enables privileges to be granted separately for a function and a
procedure with the same name.
</p>
<p>
The
<code class="literal">
Timestamp
</code>
and
<code class="literal">
Grantor
</code>
columns are unused.
</p>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="grant-tables-proxies-priv">
</a>
The proxies_priv Grant Table
</h4>
</div>
</div>
</div>
<p>
The
<code class="literal">
proxies_priv
</code>
table records information
about proxy accounts. It has these columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
Host
</code>
,
<code class="literal">
User
</code>
: The proxy
account; that is, the account that has the
<a class="link" href="privileges-provided.html#priv_proxy">
<code class="literal">
PROXY
</code>
</a>
privilege for the
proxied account.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Proxied_host
</code>
,
<code class="literal">
Proxied_user
</code>
: The proxied account.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Grantor
</code>
,
<code class="literal">
Timestamp
</code>
:
Unused.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
With_grant
</code>
: Whether the proxy account can
grant the
<a class="link" href="privileges-provided.html#priv_proxy">
<code class="literal">
PROXY
</code>
</a>
privilege to
other accounts.
</p>
</li>
</ul>
</div>
<p>
For an account to be able to grant the
<a class="link" href="privileges-provided.html#priv_proxy">
<code class="literal">
PROXY
</code>
</a>
privilege to other
accounts, it must have a row in the
<code class="literal">
proxies_priv
</code>
table with
<code class="literal">
With_grant
</code>
set to 1 and
<code class="literal">
Proxied_host
</code>
and
<code class="literal">
Proxied_user
</code>
set to indicate the account or
accounts for which the privilege can be granted. For example,
the
<code class="literal">
'root'@'localhost'
</code>
account created during
MySQL installation has a row in the
<code class="literal">
proxies_priv
</code>
table that enables granting the
<a class="link" href="privileges-provided.html#priv_proxy">
<code class="literal">
PROXY
</code>
</a>
privilege for
<code class="literal">
''@''
</code>
, that is, for all users and all hosts.
This enables
<code class="literal">
root
</code>
to set up proxy users, as
well as to delegate to other accounts the authority to set up
proxy users. See
<a class="xref" href="proxy-users.html" title="8.2.19 Proxy Users">
Section 8.2.19, “Proxy Users”
</a>
.
</p>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="grant-tables-global-grants">
</a>
The global_grants Grant Table
</h4>
</div>
</div>
</div>
<p>
The
<code class="literal">
global_grants
</code>
table lists current
assignments of dynamic global privileges to user accounts. The
table has these columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
USER
</code>
,
<code class="literal">
HOST
</code>
: The user
name and host name of the account to which the privilege is
granted.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
PRIV
</code>
: The privilege name.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
WITH_GRANT_OPTION
</code>
: Whether the account
can grant the privilege to other accounts.
</p>
</li>
</ul>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="grant-tables-default-roles">
</a>
The default_roles Grant Table
</h4>
</div>
</div>
</div>
<p>
The
<code class="literal">
default_roles
</code>
table lists default user
roles. It has these columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
HOST
</code>
,
<code class="literal">
USER
</code>
: The
account or role to which the default role applies.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
DEFAULT_ROLE_HOST
</code>
,
<code class="literal">
DEFAULT_ROLE_USER
</code>
: The default role.
</p>
</li>
</ul>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="grant-tables-role-edges">
</a>
The role_edges Grant Table
</h4>
</div>
</div>
</div>
<p>
The
<code class="literal">
role_edges
</code>
table lists edges for role
subgraphs. It has these columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
FROM_HOST
</code>
,
<code class="literal">
FROM_USER
</code>
:
The account that is granted a role.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
TO_HOST
</code>
,
<code class="literal">
TO_USER
</code>
: The
role that is granted to the account.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
WITH_ADMIN_OPTION
</code>
: Whether the account
can grant the role to and revoke it from other accounts by
using
<code class="literal">
WITH ADMIN OPTION
</code>
.
</p>
</li>
</ul>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="grant-tables-password-history">
</a>
The password_history Grant Table
</h4>
</div>
</div>
</div>
<p>
The
<code class="literal">
password_history
</code>
table contains
information about password changes. It has these columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
Host
</code>
,
<code class="literal">
User
</code>
: The
account for which the password change occurred.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Password_timestamp
</code>
: The time when the
password change occurred.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
Password
</code>
: The new password hash value.
</p>
</li>
</ul>
</div>
<p>
The
<code class="literal">
password_history
</code>
table accumulates a
sufficient number of nonempty passwords per account to enable
MySQL to perform checks against both the account password
history length and reuse interval. Automatic pruning of entries
that are outside both limits occurs when password-change
attempts occur.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
The empty password does not count in the password history and
is subject to reuse at any time.
</p>
</div>
<p>
If an account is renamed, its entries are renamed to match. If
an account is dropped or its authentication plugin is changed,
its entries are removed.
</p>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="grant-tables-scope-column-properties">
</a>
Grant Table Scope Column Properties
</h4>
</div>
</div>
</div>
<p>
Scope columns in the grant tables contain strings. The default
value for each is the empty string. The following table shows
the number of characters permitted in each column.
</p>
<div class="table">
<a name="idm46045250103728">
</a>
<p class="title">
<b>
Table 8.8 Grant Table Scope Column Lengths
</b>
</p>
<div class="table-contents">
<table>
<colgroup>
<col style="width: 50%"/>
<col style="width: 50%"/>
</colgroup>
<thead>
<tr>
<th>
Column Name
</th>
<th>
Maximum Permitted Characters
</th>
</tr>
</thead>
<tbody>
<tr>
<td>
<code class="literal">
Host
</code>
,
<code class="literal">
Proxied_host
</code>
</td>
<td>
255
</td>
</tr>
<tr>
<td>
<code class="literal">
User
</code>
,
<code class="literal">
Proxied_user
</code>
</td>
<td>
32
</td>
</tr>
<tr>
<td>
<code class="literal">
Db
</code>
</td>
<td>
64
</td>
</tr>
<tr>
<td>
<code class="literal">
Table_name
</code>
</td>
<td>
64
</td>
</tr>
<tr>
<td>
<code class="literal">
Column_name
</code>
</td>
<td>
64
</td>
</tr>
<tr>
<td>
<code class="literal">
Routine_name
</code>
</td>
<td>
64
</td>
</tr>
</tbody>
</table>
</div>
</div>
<br class="table-break"/>
<a class="indexterm" name="idm46045250081808">
</a>
<a class="indexterm" name="idm46045250080320">
</a>
<p>
<code class="literal">
Host
</code>
and
<code class="literal">
Proxied_host
</code>
values are converted to lowercase before being stored in the
grant tables.
</p>
<p>
For access-checking purposes, comparisons of
<code class="literal">
User
</code>
,
<code class="literal">
Proxied_user
</code>
,
<code class="literal">
authentication_string
</code>
,
<code class="literal">
Db
</code>
,
and
<code class="literal">
Table_name
</code>
values are case-sensitive.
Comparisons of
<code class="literal">
Host
</code>
,
<code class="literal">
Proxied_host
</code>
,
<code class="literal">
Column_name
</code>
,
and
<code class="literal">
Routine_name
</code>
values are not
case-sensitive.
</p>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="grant-tables-privilege-column-properties">
</a>
Grant Table Privilege Column Properties
</h4>
</div>
</div>
</div>
<p>
The
<code class="literal">
user
</code>
and
<code class="literal">
db
</code>
tables
list each privilege in a separate column that is declared as
<code class="literal">
ENUM('N','Y') DEFAULT 'N'
</code>
. In other words,
each privilege can be disabled or enabled, with the default
being disabled.
</p>
<p>
The
<code class="literal">
tables_priv
</code>
,
<code class="literal">
columns_priv
</code>
, and
<code class="literal">
procs_priv
</code>
tables declare the privilege
columns as
<a class="link" href="set.html" title="13.3.6 The SET Type">
<code class="literal">
SET
</code>
</a>
columns. Values in
these columns can contain any combination of the privileges
controlled by the table. Only those privileges listed in the
column value are enabled.
</p>
<div class="table">
<a name="idm46045250062128">
</a>
<p class="title">
<b>
Table 8.9 Set-Type Privilege Column Values
</b>
</p>
<div class="table-contents">
<table>
<colgroup>
<col style="width: 20%"/>
<col style="width: 25%"/>
<col style="width: 45%"/>
</colgroup>
<thead>
<tr>
<th scope="col">
Table Name
</th>
<th scope="col">
Column Name
</th>
<th scope="col">
Possible Set Elements
</th>
</tr>
</thead>
<tbody>
<tr>
<th scope="row">
<code class="literal">
tables_priv
</code>
</th>
<td>
<code class="literal">
Table_priv
</code>
</td>
<td>
<code class="literal">
'Select', 'Insert', 'Update', 'Delete', 'Create', 'Drop',
'Grant', 'References', 'Index', 'Alter', 'Create View',
'Show view', 'Trigger'
</code>
</td>
</tr>
<tr>
<th scope="row">
<code class="literal">
tables_priv
</code>
</th>
<td>
<code class="literal">
Column_priv
</code>
</td>
<td>
<code class="literal">
'Select', 'Insert', 'Update', 'References'
</code>
</td>
</tr>
<tr>
<th scope="row">
<code class="literal">
columns_priv
</code>
</th>
<td>
<code class="literal">
Column_priv
</code>
</td>
<td>
<code class="literal">
'Select', 'Insert', 'Update', 'References'
</code>
</td>
</tr>
<tr>
<th scope="row">
<code class="literal">
procs_priv
</code>
</th>
<td>
<code class="literal">
Proc_priv
</code>
</td>
<td>
<code class="literal">
'Execute', 'Alter Routine', 'Grant'
</code>
</td>
</tr>
</tbody>
</table>
</div>
</div>
<br class="table-break"/>
<p>
Only the
<code class="literal">
user
</code>
and
<code class="literal">
global_grants
</code>
tables specify administrative
privileges, such as
<a class="link" href="privileges-provided.html#priv_reload">
<code class="literal">
RELOAD
</code>
</a>
,
<a class="link" href="privileges-provided.html#priv_shutdown">
<code class="literal">
SHUTDOWN
</code>
</a>
, and
<a class="link" href="privileges-provided.html#priv_system-variables-admin">
<code class="literal">
SYSTEM_VARIABLES_ADMIN
</code>
</a>
.
Administrative operations are operations on the server itself
and are not database-specific, so there is no reason to list
these privileges in the other grant tables. Consequently, the
server need consult only the
<code class="literal">
user
</code>
and
<code class="literal">
global_grants
</code>
tables to determine whether a
user can perform an administrative operation.
</p>
<p>
The
<a class="link" href="privileges-provided.html#priv_file">
<code class="literal">
FILE
</code>
</a>
privilege also is
specified only in the
<code class="literal">
user
</code>
table. It is not
an administrative privilege as such, but a user's ability to
read or write files on the server host is independent of the
database being accessed.
</p>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="grant-tables-concurrency">
</a>
Grant Table Concurrency
</h4>
</div>
</div>
</div>
<p>
To permit concurrent DML and DDL operations on MySQL grant
tables, read operations that previously acquired row locks on
MySQL grant tables are executed as non-locking reads. Operations
that are performed as non-locking reads on MySQL grant tables
include:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
statements and other
read-only statements that read data from grant tables
through join lists and subqueries, including
<a class="link" href="innodb-locking-reads.html" title="17.7.2.4 Locking Reads">
<code class="literal">
SELECT
... FOR SHARE
</code>
</a>
statements, using any transaction
isolation level.
</p>
</li>
<li class="listitem">
<p>
DML operations that read data from grant tables (through
join lists or subqueries) but do not modify them, using any
transaction isolation level.
</p>
</li>
</ul>
</div>
<p>
Statements that no longer acquire row locks when reading data
from grant tables report a warning if executed while using
statement-based replication.
</p>
<p>
When using
-
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_format">
<code class="literal">
binlog_format=mixed
</code>
</a>
, DML
operations that read data from grant tables are written to the
binary log as row events to make the operations safe for
mixed-mode replication.
</p>
<p>
<a class="link" href="innodb-locking-reads.html" title="17.7.2.4 Locking Reads">
<code class="literal">
SELECT ...
FOR SHARE
</code>
</a>
statements that read data from grant tables
report a warning. With the
<code class="literal">
FOR SHARE
</code>
clause,
read locks are not supported on grant tables.
</p>
<p>
DML operations that read data from grant tables and are executed
using the
<a class="link" href="innodb-transaction-isolation-levels.html#isolevel_serializable">
<code class="literal">
SERIALIZABLE
</code>
</a>
isolation level report a warning. Read locks that would normally
be acquired when using the
<a class="link" href="innodb-transaction-isolation-levels.html#isolevel_serializable">
<code class="literal">
SERIALIZABLE
</code>
</a>
isolation level
are not supported on grant tables.
</p>
</div>
</div>
<br/>
</div>
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<h3 class="title">
Symbols
</h3>
<p>
[
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index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
%
</h3>
<dl>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-A">
</a>
<h3 class="title">
A
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ABS()
</h3>
<dl>
<dt>
<a class="xref" href="create-function-loadable.html" title="15.7.4.1 CREATE FUNCTION Statement for Loadable Functions">
Section 15.7.4.1, “CREATE FUNCTION Statement for Loadable Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="optimizer-statistics.html" title="10.9.6 Optimizer Statistics">
Section 10.9.6, “Optimizer Statistics”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ACOS()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ADDDATE()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
addslashes()
</h3>
<dl>
<dt>
<a class="xref" href="secure-client-programming.html" title="8.1.7 Client Programming Security Guidelines">
Section 8.1.7, “Client Programming Security Guidelines”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ADDTIME()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
AES_DECRYPT()
</h3>
<dl>
<dt>
<a class="xref" href="encryption-functions.html" title="14.13 Encryption and Compression Functions">
Section 14.13, “Encryption and Compression Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="enterprise-encryption-usage.html" title="8.6.3 MySQL Enterprise Encryption Usage and Examples">
Section 8.6.3, “MySQL Enterprise Encryption Usage and Examples”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
AES_ENCRYPT()
</h3>
<dl>
<dt>
<a class="xref" href="encryption-functions.html" title="14.13 Encryption and Compression Functions">
Section 14.13, “Encryption and Compression Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="enterprise-encryption-usage.html" title="8.6.3 MySQL Enterprise Encryption Usage and Examples">
Section 8.6.3, “MySQL Enterprise Encryption Usage and Examples”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ANY_VALUE()
</h3>
<dl>
<dt>
<a class="xref" href="group-by-modifiers.html" title="14.19.2 GROUP BY Modifiers">
Section 14.19.2, “GROUP BY Modifiers”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-by-handling.html" title="14.19.3 MySQL Handling of GROUP BY">
Section 14.19.3, “MySQL Handling of GROUP BY”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ASCII()
</h3>
<dl>
<dt>
<a class="xref" href="help.html" title="15.8.3 HELP Statement">
Section 15.8.3, “HELP Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ASIN()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
asymmetric_decrypt()
</h3>
<dl>
<dt>
<a class="xref" href="enterprise-encryption-functions.html" title="8.6.5 MySQL Enterprise Encryption Component Function Descriptions">
Section 8.6.5, “MySQL Enterprise Encryption Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
asymmetric_encrypt()
</h3>
<dl>
<dt>
<a class="xref" href="enterprise-encryption-functions.html" title="8.6.5 MySQL Enterprise Encryption Component Function Descriptions">
Section 8.6.5, “MySQL Enterprise Encryption Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
asymmetric_sign()
</h3>
<dl>
<dt>
<a class="xref" href="enterprise-encryption-functions.html" title="8.6.5 MySQL Enterprise Encryption Component Function Descriptions">
Section 8.6.5, “MySQL Enterprise Encryption Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
asymmetric_verify()
</h3>
<dl>
<dt>
<a class="xref" href="enterprise-encryption-functions.html" title="8.6.5 MySQL Enterprise Encryption Component Function Descriptions">
Section 8.6.5, “MySQL Enterprise Encryption Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
asynchronous_connection_failover_add_managed
</h3>
<dl>
<dt>
<a class="xref" href="replication-asynchronous-connection-failover-source.html" title="19.4.9.1 Asynchronous Connection Failover for Sources">
Section 19.4.9.1, “Asynchronous Connection Failover for Sources”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-replication-asynchronous-connection-failover-table.html" title="29.12.11.8 The replication_asynchronous_connection_failover Table">
Section 29.12.11.8, “The replication_asynchronous_connection_failover Table”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
asynchronous_connection_failover_add_managed()
</h3>
<dl>
<dt>
<a class="xref" href="replication-asynchronous-connection-failover-replica.html" title="19.4.9.2 Asynchronous Connection Failover for Replicas">
Section 19.4.9.2, “Asynchronous Connection Failover for Replicas”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-functions-async-failover.html" title="14.18.3 Asynchronous Replication Channel Failover Functions">
Section 14.18.3, “Asynchronous Replication Channel Failover Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="change-replication-source-to.html" title="15.4.2.2 CHANGE REPLICATION SOURCE TO Statement">
Section 15.4.2.2, “CHANGE REPLICATION SOURCE TO Statement”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
asynchronous_connection_failover_add_source
</h3>
<dl>
<dt>
<a class="xref" href="replication-asynchronous-connection-failover-source.html" title="19.4.9.1 Asynchronous Connection Failover for Sources">
Section 19.4.9.1, “Asynchronous Connection Failover for Sources”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-replication-asynchronous-connection-failover-table.html" title="29.12.11.8 The replication_asynchronous_connection_failover Table">
Section 29.12.11.8, “The replication_asynchronous_connection_failover Table”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
asynchronous_connection_failover_add_source()
</h3>
<dl>
<dt>
<a class="xref" href="replication-asynchronous-connection-failover-replica.html" title="19.4.9.2 Asynchronous Connection Failover for Replicas">
Section 19.4.9.2, “Asynchronous Connection Failover for Replicas”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-functions-async-failover.html" title="14.18.3 Asynchronous Replication Channel Failover Functions">
Section 14.18.3, “Asynchronous Replication Channel Failover Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="change-replication-source-to.html" title="15.4.2.2 CHANGE REPLICATION SOURCE TO Statement">
Section 15.4.2.2, “CHANGE REPLICATION SOURCE TO Statement”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
asynchronous_connection_failover_delete_managed
</h3>
<dl>
<dt>
<a class="xref" href="replication-asynchronous-connection-failover-source.html" title="19.4.9.1 Asynchronous Connection Failover for Sources">
Section 19.4.9.1, “Asynchronous Connection Failover for Sources”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-replication-asynchronous-connection-failover-table.html" title="29.12.11.8 The replication_asynchronous_connection_failover Table">
Section 29.12.11.8, “The replication_asynchronous_connection_failover Table”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
asynchronous_connection_failover_delete_managed()
</h3>
<dl>
<dt>
<a class="xref" href="replication-asynchronous-connection-failover-replica.html" title="19.4.9.2 Asynchronous Connection Failover for Replicas">
Section 19.4.9.2, “Asynchronous Connection Failover for Replicas”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-functions-async-failover.html" title="14.18.3 Asynchronous Replication Channel Failover Functions">
Section 14.18.3, “Asynchronous Replication Channel Failover Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="change-replication-source-to.html" title="15.4.2.2 CHANGE REPLICATION SOURCE TO Statement">
Section 15.4.2.2, “CHANGE REPLICATION SOURCE TO Statement”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
asynchronous_connection_failover_delete_source
</h3>
<dl>
<dt>
<a class="xref" href="replication-asynchronous-connection-failover-source.html" title="19.4.9.1 Asynchronous Connection Failover for Sources">
Section 19.4.9.1, “Asynchronous Connection Failover for Sources”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-replication-asynchronous-connection-failover-table.html" title="29.12.11.8 The replication_asynchronous_connection_failover Table">
Section 29.12.11.8, “The replication_asynchronous_connection_failover Table”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
asynchronous_connection_failover_delete_source()
</h3>
<dl>
<dt>
<a class="xref" href="replication-asynchronous-connection-failover-replica.html" title="19.4.9.2 Asynchronous Connection Failover for Replicas">
Section 19.4.9.2, “Asynchronous Connection Failover for Replicas”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-functions-async-failover.html" title="14.18.3 Asynchronous Replication Channel Failover Functions">
Section 14.18.3, “Asynchronous Replication Channel Failover Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="change-replication-source-to.html" title="15.4.2.2 CHANGE REPLICATION SOURCE TO Statement">
Section 15.4.2.2, “CHANGE REPLICATION SOURCE TO Statement”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
asynchronous_connection_failover_reset()
</h3>
<dl>
<dt>
<a class="xref" href="replication-functions-async-failover.html" title="14.18.3 Asynchronous Replication Channel Failover Functions">
Section 14.18.3, “Asynchronous Replication Channel Failover Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ATAN()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ATAN2()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
audit_api_message_emit_udf()
</h3>
<dl>
<dt>
<a class="xref" href="audit-api-message-emit.html" title="8.4.6 The Audit Message Component">
Section 8.4.6, “The Audit Message Component”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="audit-log-filter-definitions.html" title="8.4.5.8 Writing Audit Log Filter Definitions">
Section 8.4.5.8, “Writing Audit Log Filter Definitions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
audit_log_encryption_password_get()
</h3>
<dl>
<dt>
<a class="xref" href="audit-log-reference.html" title="8.4.5.11 Audit Log Reference">
Section 8.4.5.11, “Audit Log Reference”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="audit-log-logging-configuration.html" title="8.4.5.5 Configuring Audit Logging Characteristics">
Section 8.4.5.5, “Configuring Audit Logging Characteristics”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
audit_log_encryption_password_set()
</h3>
<dl>
<dt>
<a class="xref" href="audit-log-reference.html" title="8.4.5.11 Audit Log Reference">
Section 8.4.5.11, “Audit Log Reference”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="audit-log-logging-configuration.html" title="8.4.5.5 Configuring Audit Logging Characteristics">
Section 8.4.5.5, “Configuring Audit Logging Characteristics”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
audit_log_filter_flush()
</h3>
<dl>
<dt>
<a class="xref" href="audit-log-filtering.html" title="8.4.5.7 Audit Log Filtering">
Section 8.4.5.7, “Audit Log Filtering”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="audit-log-reference.html" title="8.4.5.11 Audit Log Reference">
Section 8.4.5.11, “Audit Log Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
audit_log_filter_remove_filter()
</h3>
<dl>
<dt>
<a class="xref" href="audit-log-filtering.html" title="8.4.5.7 Audit Log Filtering">
Section 8.4.5.7, “Audit Log Filtering”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="audit-log-reference.html" title="8.4.5.11 Audit Log Reference">
Section 8.4.5.11, “Audit Log Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
audit_log_filter_remove_user()
</h3>
<dl>
<dt>
<a class="xref" href="audit-log-filtering.html" title="8.4.5.7 Audit Log Filtering">
Section 8.4.5.7, “Audit Log Filtering”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="audit-log-reference.html" title="8.4.5.11 Audit Log Reference">
Section 8.4.5.11, “Audit Log Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
audit_log_filter_set_filter()
</h3>
<dl>
<dt>
<a class="xref" href="audit-log-file-formats.html" title="8.4.5.4 Audit Log File Formats">
Section 8.4.5.4, “Audit Log File Formats”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="audit-log-filtering.html" title="8.4.5.7 Audit Log Filtering">
Section 8.4.5.7, “Audit Log Filtering”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="audit-log-reference.html" title="8.4.5.11 Audit Log Reference">
Section 8.4.5.11, “Audit Log Reference”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="audit-log-logging-configuration.html" title="8.4.5.5 Configuring Audit Logging Characteristics">
Section 8.4.5.5, “Configuring Audit Logging Characteristics”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
audit_log_filter_set_user()
</h3>
<dl>
<dt>
<a class="xref" href="audit-log-filtering.html" title="8.4.5.7 Audit Log Filtering">
Section 8.4.5.7, “Audit Log Filtering”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="audit-log-reference.html" title="8.4.5.11 Audit Log Reference">
Section 8.4.5.11, “Audit Log Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
audit_log_read()
</h3>
<dl>
<dt>
<a class="xref" href="audit-log-reference.html" title="8.4.5.11 Audit Log Reference">
Section 8.4.5.11, “Audit Log Reference”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="audit-log-logging-configuration.html" title="8.4.5.5 Configuring Audit Logging Characteristics">
Section 8.4.5.5, “Configuring Audit Logging Characteristics”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="audit-log-file-reading.html" title="8.4.5.6 Reading Audit Log Files">
Section 8.4.5.6, “Reading Audit Log Files”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
audit_log_read_bookmark()
</h3>
<dl>
<dt>
<a class="xref" href="audit-log-reference.html" title="8.4.5.11 Audit Log Reference">
Section 8.4.5.11, “Audit Log Reference”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="audit-log-file-reading.html" title="8.4.5.6 Reading Audit Log Files">
Section 8.4.5.6, “Reading Audit Log Files”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
audit_log_rotate()
</h3>
<dl>
<dt>
<a class="xref" href="audit-log-reference.html" title="8.4.5.11 Audit Log Reference">
Section 8.4.5.11, “Audit Log Reference”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="audit-log-logging-configuration.html" title="8.4.5.5 Configuring Audit Logging Characteristics">
Section 8.4.5.5, “Configuring Audit Logging Characteristics”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
AVG(
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
AVG()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-type-syntax.html" title="13.2.1 Date and Time Data Type Syntax">
Section 13.2.1, “Date and Time Data Type Syntax”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-by-optimization.html" title="10.2.1.17 GROUP BY Optimization">
Section 10.2.1.17, “GROUP BY Optimization”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="enum.html" title="13.3.5 The ENUM Type">
Section 13.3.5, “The ENUM Type”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="features.html" title="1.2.2 The Main Features of MySQL">
Section 1.2.2, “The Main Features of MySQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="set.html" title="13.3.6 The SET Type">
Section 13.3.6, “The SET Type”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="window-functions-frames.html" title="14.20.3 Window Function Frame Specification">
Section 14.20.3, “Window Function Frame Specification”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-B">
</a>
<h3 class="title">
B
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
BENCHMARK()
</h3>
<dl>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="select-benchmarking.html" title="10.13.1 Measuring the Speed of Expressions and Functions">
Section 10.13.1, “Measuring the Speed of Expressions and Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
BIN()
</h3>
<dl>
<dt>
<a class="xref" href="bit-value-literals.html" title="11.1.5 Bit-Value Literals">
Section 11.1.5, “Bit-Value Literals”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
BIN_TO_UUID()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
BIT_AND()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="bit-functions.html" title="14.12 Bit Functions and Operators">
Section 14.12, “Bit Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
BIT_COUNT()
</h3>
<dl>
<dt>
<a class="xref" href="bit-functions.html" title="14.12 Bit Functions and Operators">
Section 14.12, “Bit Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
BIT_LENGTH()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
BIT_OR()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="bit-functions.html" title="14.12 Bit Functions and Operators">
Section 14.12, “Bit Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
BIT_XOR()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="bit-functions.html" title="14.12 Bit Functions and Operators">
Section 14.12, “Bit Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-C">
</a>
<h3 class="title">
C
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CAN_ACCESS_COLUMN()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CAN_ACCESS_DATABASE()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CAN_ACCESS_TABLE()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CAN_ACCESS_USER()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CAN_ACCESS_VIEW()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CAST()
</h3>
<dl>
<dt>
<a class="xref" href="bit-functions.html" title="14.12 Bit Functions and Operators">
Section 14.12, “Bit Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="bit-value-literals.html" title="11.1.5 Bit-Value Literals">
Section 11.1.5, “Bit-Value Literals”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="cast-functions.html" title="14.10 Cast Functions and Operators">
Section 14.10, “Cast Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="comparison-operators.html" title="14.4.2 Comparison Functions and Operators">
Section 14.4.2, “Comparison Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-type-conversion.html" title="13.2.8 Conversion Between Date and Time Types">
Section 13.2.8, “Conversion Between Date and Time Types”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-index.html" title="15.1.15 CREATE INDEX Statement">
Section 15.1.15, “CREATE INDEX Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="expressions.html" title="11.5 Expressions">
Section 11.5, “Expressions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-creation-functions.html" title="14.17.2 Functions That Create JSON Values">
Section 14.17.2, “Functions That Create JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-search-functions.html" title="14.17.3 Functions That Search JSON Values">
Section 14.17.3, “Functions That Search JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="hexadecimal-literals.html" title="11.1.4 Hexadecimal Literals">
Section 11.1.4, “Hexadecimal Literals”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="differences-from-ansi.html" title="1.7.2 MySQL Differences from Standard SQL">
Section 1.7.2, “MySQL Differences from Standard SQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="prepare.html" title="15.5.1 PREPARE Statement">
Section 15.5.1, “PREPARE Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="datetime.html" title="13.2.2 The DATE, DATETIME, and TIMESTAMP Types">
Section 13.2.2, “The DATE, DATETIME, and TIMESTAMP Types”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="type-conversion.html" title="14.3 Type Conversion in Expression Evaluation">
Section 14.3, “Type Conversion in Expression Evaluation”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="user-variables.html" title="11.4 User-Defined Variables">
Section 11.4, “User-Defined Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="with.html" title="15.2.20 WITH (Common Table Expressions)">
Section 15.2.20, “WITH (Common Table Expressions)”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CAST(expr AS type
</h3>
<dl>
<dt>
<a class="xref" href="cast-functions.html" title="14.10 Cast Functions and Operators">
Section 14.10, “Cast Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CEIL()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CEILING()
</h3>
<dl>
<dt>
<a class="xref" href="partitioning-linear-hash.html" title="26.2.4.1 LINEAR HASH Partitioning">
Section 26.2.4.1, “LINEAR HASH Partitioning”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CHAR()
</h3>
<dl>
<dt>
<a class="xref" href="mysql-command-options.html" title="6.5.1.1 mysql Client Options">
Section 6.5.1.1, “mysql Client Options”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CHAR_LENGTH()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-unicode-sets.html" title="12.10.1 Unicode Character Sets">
Section 12.10.1, “Unicode Character Sets”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CHARACTER_LENGTH()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CHARSET()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
COALESCE
</h3>
<dl>
<dt>
<a class="xref" href="prepare.html" title="15.5.1 PREPARE Statement">
Section 15.5.1, “PREPARE Statement”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
COALESCE()
</h3>
<dl>
<dt>
<a class="xref" href="comparison-operators.html" title="14.4.2 Comparison Functions and Operators">
Section 14.4.2, “Comparison Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="join.html" title="15.2.13.2 JOIN Clause">
Section 15.2.13.2, “JOIN Clause”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="prepare.html" title="15.5.1 PREPARE Statement">
Section 15.5.1, “PREPARE Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="with.html" title="15.2.20 WITH (Common Table Expressions)">
Section 15.2.20, “WITH (Common Table Expressions)”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
COERCIBILITY()
</h3>
<dl>
<dt>
<a class="xref" href="charset-collation-coercibility.html" title="12.8.4 Collation Coercibility in Expressions">
Section 12.8.4, “Collation Coercibility in Expressions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
COLLATION()
</h3>
<dl>
<dt>
<a class="xref" href="case-sensitivity.html" title="B.3.4.1 Case Sensitivity in String Searches">
Section B.3.4.1, “Case Sensitivity in String Searches”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
COMPRESS()
</h3>
<dl>
<dt>
<a class="xref" href="encryption-functions.html" title="14.13 Encryption and Compression Functions">
Section 14.13, “Encryption and Compression Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="source-configuration-options.html" title="2.8.7 MySQL Source-Configuration Options">
Section 2.8.7, “MySQL Source-Configuration Options”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CONCAT()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="cast-functions.html" title="14.10 Cast Functions and Operators">
Section 14.10, “Cast Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-repertoire.html" title="12.2.1 Character Set Repertoire">
Section 12.2.1, “Character Set Repertoire”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-collation-coercibility.html" title="12.8.4 Collation Coercibility in Expressions">
Section 12.8.4, “Collation Coercibility in Expressions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-function-loadable.html" title="15.7.4.1 CREATE FUNCTION Statement for Loadable Functions">
Section 15.7.4.1, “CREATE FUNCTION Statement for Loadable Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="logical-operators.html" title="14.4.3 Logical Operators">
Section 14.4.3, “Logical Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="sql-mode.html" title="7.1.11 Server SQL Modes">
Section 7.1.11, “Server SQL Modes”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="show-create-view.html" title="15.7.7.14 SHOW CREATE VIEW Statement">
Section 15.7.7.14, “SHOW CREATE VIEW Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-schema-views-table.html" title="28.3.47 The INFORMATION_SCHEMA VIEWS Table">
Section 28.3.47, “The INFORMATION_SCHEMA VIEWS Table”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="type-conversion.html" title="14.3 Type Conversion in Expression Evaluation">
Section 14.3, “Type Conversion in Expression Evaluation”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="xml-functions.html" title="14.11 XML Functions">
Section 14.11, “XML Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CONCAT_WS()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CONNECTION_ID()
</h3>
<dl>
<dt>
<a class="xref" href="audit-log-file-formats.html" title="8.4.5.4 Audit Log File Formats">
Section 8.4.5.4, “Audit Log File Formats”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-table-check-constraints.html" title="15.1.20.6 CHECK Constraints">
Section 15.1.20.6, “CHECK Constraints”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-table-generated-columns.html" title="15.1.20.8 CREATE TABLE and Generated Columns">
Section 15.1.20.8, “CREATE TABLE and Generated Columns”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="kill.html" title="15.7.8.4 KILL Statement">
Section 15.7.8.4, “KILL Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mysql-logging.html" title="6.5.1.3 mysql Client Logging">
Section 6.5.1.3, “mysql Client Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-functions.html" title="14.21 Performance Schema Functions">
Section 14.21, “Performance Schema Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="show-processlist.html" title="15.7.7.31 SHOW PROCESSLIST Statement">
Section 15.7.7.31, “SHOW PROCESSLIST Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-error-log-table.html" title="29.12.22.2 The error_log Table">
Section 29.12.22.2, “The error_log Table”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-schema-processlist-table.html" title="28.3.23 The INFORMATION_SCHEMA PROCESSLIST Table">
Section 28.3.23, “The INFORMATION_SCHEMA PROCESSLIST Table”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-processlist-table.html" title="29.12.22.7 The processlist Table">
Section 29.12.22.7, “The processlist Table”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-threads-table.html" title="29.12.22.8 The threads Table">
Section 29.12.22.8, “The threads Table”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-tp-connections-table.html" title="29.12.16.1 The tp_connections Table">
Section 29.12.16.1, “The tp_connections Table”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CONV()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CONVERT()
</h3>
<dl>
<dt>
<a class="xref" href="cast-functions.html" title="14.10 Cast Functions and Operators">
Section 14.10, “Cast Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-introducer.html" title="12.3.8 Character Set Introducers">
Section 12.3.8, “Character Set Introducers”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-literal.html" title="12.3.6 Character String Literal Character Set and Collation">
Section 12.3.6, “Character String Literal Character Set and Collation”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="comparison-operators.html" title="14.4.2 Comparison Functions and Operators">
Section 14.4.2, “Comparison Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="faqs-cjk.html" title="A.11 MySQL 8.4 FAQ: MySQL Chinese, Japanese, and Korean Character Sets">
Section A.11, “MySQL 8.4 FAQ: MySQL Chinese, Japanese, and Korean
Character Sets”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mysql-command-options.html" title="6.5.1.1 mysql Client Options">
Section 6.5.1.1, “mysql Client Options”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-usage.html" title="8.5.3.2 Using the MySQL Enterprise Data Masking and De-Identification Plugin">
Section 8.5.3.2, “Using the MySQL Enterprise Data Masking and De-Identification Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CONVERT_TZ()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="timestamp-lookups.html" title="10.3.14 Indexed Lookups from TIMESTAMP Columns">
Section 10.3.14, “Indexed Lookups from TIMESTAMP Columns”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="lock-tables.html" title="15.3.6 LOCK TABLES and UNLOCK TABLES Statements">
Section 15.3.6, “LOCK TABLES and UNLOCK TABLES Statements”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="query-log.html" title="7.4.3 The General Query Log">
Section 7.4.3, “The General Query Log”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="slow-query-log.html" title="7.4.5 The Slow Query Log">
Section 7.4.5, “The Slow Query Log”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
COS()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
COT()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
COUNT()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="correlated-subqueries.html" title="15.2.15.7 Correlated Subqueries">
Section 15.2.15.7, “Correlated Subqueries”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="counting-rows.html" title="5.3.4.8 Counting Rows">
Section 5.3.4.8, “Counting Rows”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-function-loadable.html" title="15.7.4.1 CREATE FUNCTION Statement for Loadable Functions">
Section 15.7.4.1, “CREATE FUNCTION Statement for Loadable Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-by-optimization.html" title="10.2.1.17 GROUP BY Optimization">
Section 10.2.1.17, “GROUP BY Optimization”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="innodb-restrictions-limitations.html" title="17.22 InnoDB Restrictions and Limitations">
Section 17.22, “InnoDB Restrictions and Limitations”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="internal-temporary-tables.html" title="10.4.4 Internal Temporary Table Use in MySQL">
Section 10.4.4, “Internal Temporary Table Use in MySQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mysql-cluster-limitations-transactions.html" title="25.2.7.3 Limits Relating to Transaction Handling in NDB Cluster">
Section 25.2.7.3, “Limits Relating to Transaction Handling in NDB Cluster”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mysql-cluster-options-variables.html#mysql-cluster-status-variables" title="25.4.3.9.3 NDB Cluster Status Variables">
Section 25.4.3.9.3, “NDB Cluster Status Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="derived-table-optimization.html" title="10.2.2.4 Optimizing Derived Tables, View References, and Common Table Expressions with Merging or Materialization">
Section 10.2.2.4, “Optimizing Derived Tables, View References, and Common Table Expressions
with Merging or Materialization”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="problems-with-null.html" title="B.3.4.3 Problems with NULL Values">
Section B.3.4.3, “Problems with NULL Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="sql-mode.html" title="7.1.11 Server SQL Modes">
Section 7.1.11, “Server SQL Modes”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="features.html" title="1.2.2 The Main Features of MySQL">
Section 1.2.2, “The Main Features of MySQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="view-updatability.html" title="27.5.3 Updatable and Insertable Views">
Section 27.5.3, “Updatable and Insertable Views”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="where-optimization.html" title="10.2.1.1 WHERE Clause Optimization">
Section 10.2.1.1, “WHERE Clause Optimization”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CRC32()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
create_asymmetric_priv_key()
</h3>
<dl>
<dt>
<a class="xref" href="enterprise-encryption-functions.html" title="8.6.5 MySQL Enterprise Encryption Component Function Descriptions">
Section 8.6.5, “MySQL Enterprise Encryption Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
create_asymmetric_pub_key()
</h3>
<dl>
<dt>
<a class="xref" href="enterprise-encryption-functions.html" title="8.6.5 MySQL Enterprise Encryption Component Function Descriptions">
Section 8.6.5, “MySQL Enterprise Encryption Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
create_digest()
</h3>
<dl>
<dt>
<a class="xref" href="enterprise-encryption-functions.html" title="8.6.5 MySQL Enterprise Encryption Component Function Descriptions">
Section 8.6.5, “MySQL Enterprise Encryption Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CUME_DIST()
</h3>
<dl>
<dt>
<a class="xref" href="window-function-descriptions.html" title="14.20.1 Window Function Descriptions">
Section 14.20.1, “Window Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CURDATE()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-calculations.html" title="5.3.4.5 Date Calculations">
Section 5.3.4.5, “Date Calculations”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CURRENT_DATE
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CURRENT_DATE()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-type-conversion.html" title="13.2.8 Conversion Between Date and Time Types">
Section 13.2.8, “Conversion Between Date and Time Types”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CURRENT_ROLE()
</h3>
<dl>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="roles.html" title="8.2.10 Using Roles">
Section 8.2.10, “Using Roles”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CURRENT_TIME
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CURRENT_TIME()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CURRENT_TIMESTAMP
</h3>
<dl>
<dt>
<a class="xref" href="timestamp-initialization.html" title="13.2.5 Automatic Initialization and Updating for TIMESTAMP and DATETIME">
Section 13.2.5, “Automatic Initialization and Updating for TIMESTAMP and DATETIME”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-event.html" title="15.1.13 CREATE EVENT Statement">
Section 15.1.13, “CREATE EVENT Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-table-generated-columns.html" title="15.1.20.8 CREATE TABLE and Generated Columns">
Section 15.1.20.8, “CREATE TABLE and Generated Columns”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-type-defaults.html" title="13.6 Data Type Default Values">
Section 13.6, “Data Type Default Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CURRENT_TIMESTAMP()
</h3>
<dl>
<dt>
<a class="xref" href="timestamp-initialization.html" title="13.2.5 Automatic Initialization and Updating for TIMESTAMP and DATETIME">
Section 13.2.5, “Automatic Initialization and Updating for TIMESTAMP and DATETIME”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CURRENT_USER
</h3>
<dl>
<dt>
<a class="xref" href="alter-user.html" title="15.7.1.1 ALTER USER Statement">
Section 15.7.1.1, “ALTER USER Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-event.html" title="15.1.13 CREATE EVENT Statement">
Section 15.1.13, “CREATE EVENT Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-procedure.html" title="15.1.17 CREATE PROCEDURE and CREATE FUNCTION Statements">
Section 15.1.17, “CREATE PROCEDURE and CREATE FUNCTION Statements”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-trigger.html" title="15.1.22 CREATE TRIGGER Statement">
Section 15.1.22, “CREATE TRIGGER Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-view.html" title="15.1.23 CREATE VIEW Statement">
Section 15.1.23, “CREATE VIEW Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="grant.html" title="15.7.1.6 GRANT Statement">
Section 15.7.1.6, “GRANT Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="grant-tables.html" title="8.2.3 Grant Tables">
Section 8.2.3, “Grant Tables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="binary-log-mixed.html" title="7.4.4.3 Mixed Binary Logging Format">
Section 7.4.4.3, “Mixed Binary Logging Format”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-functions.html" title="19.5.1.14 Replication and System Functions">
Section 19.5.1.14, “Replication and System Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-current-user.html" title="19.5.1.8 Replication of CURRENT_USER()">
Section 19.5.1.8, “Replication of CURRENT_USER()”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="show-create-user.html" title="15.7.7.13 SHOW CREATE USER Statement">
Section 15.7.7.13, “SHOW CREATE USER Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="account-names.html" title="8.2.4 Specifying Account Names">
Section 8.2.4, “Specifying Account Names”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="stored-objects-security.html" title="27.6 Stored Object Access Control">
Section 27.6, “Stored Object Access Control”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CURRENT_USER()
</h3>
<dl>
<dt>
<a class="xref" href="connection-access.html" title="8.2.6 Access Control, Stage 1: Connection Verification">
Section 8.2.6, “Access Control, Stage 1: Connection Verification”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="alter-user.html" title="15.7.1.1 ALTER USER Statement">
Section 15.7.1.1, “ALTER USER Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="audit-log-file-formats.html" title="8.4.5.4 Audit Log File Formats">
Section 8.4.5.4, “Audit Log File Formats”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-table-check-constraints.html" title="15.1.20.6 CHECK Constraints">
Section 15.1.20.6, “CHECK Constraints”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="connection-control-installation.html" title="8.4.2.1 Connection-Control Plugin Installation">
Section 8.4.2.1, “Connection-Control Plugin Installation”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-event.html" title="15.1.13 CREATE EVENT Statement">
Section 15.1.13, “CREATE EVENT Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-procedure.html" title="15.1.17 CREATE PROCEDURE and CREATE FUNCTION Statements">
Section 15.1.17, “CREATE PROCEDURE and CREATE FUNCTION Statements”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-table-generated-columns.html" title="15.1.20.8 CREATE TABLE and Generated Columns">
Section 15.1.20.8, “CREATE TABLE and Generated Columns”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-trigger.html" title="15.1.22 CREATE TRIGGER Statement">
Section 15.1.22, “CREATE TRIGGER Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-view.html" title="15.1.23 CREATE VIEW Statement">
Section 15.1.23, “CREATE VIEW Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="keyring-functions-general-purpose.html" title="8.4.4.12 General-Purpose Keyring Key-Management Functions">
Section 8.4.4.12, “General-Purpose Keyring Key-Management Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="grant.html" title="15.7.1.6 GRANT Statement">
Section 15.7.1.6, “GRANT Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="ldap-pluggable-authentication.html" title="8.4.1.7 LDAP Pluggable Authentication">
Section 8.4.1.7, “LDAP Pluggable Authentication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="binary-log-mixed.html" title="7.4.4.3 Mixed Binary Logging Format">
Section 7.4.4.3, “Mixed Binary Logging Format”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="password-management.html" title="8.2.15 Password Management">
Section 8.2.15, “Password Management”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="validate-password-options-variables.html" title="8.4.3.2 Password Validation Options and Variables">
Section 8.4.3.2, “Password Validation Options and Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="proxy-users.html" title="8.2.19 Proxy Users">
Section 8.2.19, “Proxy Users”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-functions.html" title="19.5.1.14 Replication and System Functions">
Section 19.5.1.14, “Replication and System Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-current-user.html" title="19.5.1.8 Replication of CURRENT_USER()">
Section 19.5.1.8, “Replication of CURRENT_USER()”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="set-password.html" title="15.7.1.10 SET PASSWORD Statement">
Section 15.7.1.10, “SET PASSWORD Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="show-create-user.html" title="15.7.7.13 SHOW CREATE USER Statement">
Section 15.7.7.13, “SHOW CREATE USER Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="account-names.html" title="8.2.4 Specifying Account Names">
Section 8.2.4, “Specifying Account Names”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="role-names.html" title="8.2.5 Specifying Role Names">
Section 8.2.5, “Specifying Role Names”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="account-activity-auditing.html" title="8.2.23 SQL-Based Account Activity Auditing">
Section 8.2.23, “SQL-Based Account Activity Auditing”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="stored-objects-security.html" title="27.6 Stored Object Access Control">
Section 27.6, “Stored Object Access Control”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="keyring-service.html" title="7.6.9.2 The Keyring Service">
Section 7.6.9.2, “The Keyring Service”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-metadata.html" title="12.2.2 UTF-8 for Metadata">
Section 12.2.2, “UTF-8 for Metadata”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
CURTIME()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="time-zone-support.html" title="7.1.15 MySQL Server Time Zone Support">
Section 7.1.15, “MySQL Server Time Zone Support”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-D">
</a>
<h3 class="title">
D
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
DATABASE()
</h3>
<dl>
<dt>
<a class="xref" href="creating-database.html" title="5.3.1 Creating and Selecting a Database">
Section 5.3.1, “Creating and Selecting a Database”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="drop-database.html" title="15.1.24 DROP DATABASE Statement">
Section 15.1.24, “DROP DATABASE Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="getting-information.html" title="5.4 Getting Information About Databases and Tables">
Section 5.4, “Getting Information About Databases and Tables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="known-issues.html" title="B.3.7 Known Issues in MySQL">
Section B.3.7, “Known Issues in MySQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-metadata.html" title="12.2.2 UTF-8 for Metadata">
Section 12.2.2, “UTF-8 for Metadata”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
DATE()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
DATE_ADD()
</h3>
<dl>
<dt>
<a class="xref" href="arithmetic-functions.html" title="14.6.1 Arithmetic Operators">
Section 14.6.1, “Arithmetic Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-types.html" title="13.2 Date and Time Data Types">
Section 13.2, “Date and Time Data Types”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-calculations.html" title="5.3.4.5 Date Calculations">
Section 5.3.4.5, “Date Calculations”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="expressions.html" title="11.5 Expressions">
Section 11.5, “Expressions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="window-functions-frames.html" title="14.20.3 Window Function Frame Specification">
Section 14.20.3, “Window Function Frame Specification”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
DATE_FORMAT()
</h3>
<dl>
<dt>
<a class="xref" href="cast-functions.html" title="14.10 Cast Functions and Operators">
Section 14.10, “Cast Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="locale-support.html" title="12.16 MySQL Server Locale Support">
Section 12.16, “MySQL Server Locale Support”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
DATE_SUB()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-types.html" title="13.2 Date and Time Data Types">
Section 13.2, “Date and Time Data Types”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="expressions.html" title="11.5 Expressions">
Section 11.5, “Expressions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
DATEDIFF()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
DAY()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
DAYNAME()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="locale-support.html" title="12.16 MySQL Server Locale Support">
Section 12.16, “MySQL Server Locale Support”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
DAYOFMONTH()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-calculations.html" title="5.3.4.5 Date Calculations">
Section 5.3.4.5, “Date Calculations”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
DAYOFWEEK()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
DAYOFYEAR()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-types.html" title="26.2 Partitioning Types">
Section 26.2, “Partitioning Types”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
DEFAULT()
</h3>
<dl>
<dt>
<a class="xref" href="alter-table-generated-columns.html" title="15.1.9.2 ALTER TABLE and Generated Columns">
Section 15.1.9.2, “ALTER TABLE and Generated Columns”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-type-defaults.html" title="13.6 Data Type Default Values">
Section 13.6, “Data Type Default Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="insert.html" title="15.2.7 INSERT Statement">
Section 15.2.7, “INSERT Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replace.html" title="15.2.12 REPLACE Statement">
Section 15.2.12, “REPLACE Statement”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
DEGREES()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
DENSE_RANK()
</h3>
<dl>
<dt>
<a class="xref" href="window-function-descriptions.html" title="14.20.1 Window Function Descriptions">
Section 14.20.1, “Window Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-E">
</a>
<h3 class="title">
E
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ELT()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="known-issues.html" title="B.3.7 Known Issues in MySQL">
Section B.3.7, “Known Issues in MySQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
EXP()
</h3>
<dl>
<dt>
<a class="xref" href="create-table.html" title="15.1.20 CREATE TABLE Statement">
Section 15.1.20, “CREATE TABLE Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
EXPORT_SET()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
EXTRACT()
</h3>
<dl>
<dt>
<a class="xref" href="cast-functions.html" title="14.10 Cast Functions and Operators">
Section 14.10, “Cast Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="expressions.html" title="11.5 Expressions">
Section 11.5, “Expressions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ExtractValue()
</h3>
<dl>
<dt>
<a class="xref" href="xml-functions.html" title="14.11 XML Functions">
Section 14.11, “XML Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-F">
</a>
<h3 class="title">
F
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
FIELD()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
FIND_IN_SET()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="set.html" title="13.3.6 The SET Type">
Section 13.3.6, “The SET Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
firewall_group_delist()
</h3>
<dl>
<dt>
<a class="xref" href="firewall-reference.html" title="8.4.7.4 MySQL Enterprise Firewall Reference">
Section 8.4.7.4, “MySQL Enterprise Firewall Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
firewall_group_enlist()
</h3>
<dl>
<dt>
<a class="xref" href="firewall-reference.html" title="8.4.7.4 MySQL Enterprise Firewall Reference">
Section 8.4.7.4, “MySQL Enterprise Firewall Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
FIRST_VALUE()
</h3>
<dl>
<dt>
<a class="xref" href="window-function-descriptions.html" title="14.20.1 Window Function Descriptions">
Section 14.20.1, “Window Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="window-functions-frames.html" title="14.20.3 Window Function Frame Specification">
Section 14.20.3, “Window Function Frame Specification”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
FLOOR()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-by-handling.html" title="14.19.3 MySQL Handling of GROUP BY">
Section 14.19.3, “MySQL Handling of GROUP BY”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="optimizer-statistics.html" title="10.9.6 Optimizer Statistics">
Section 10.9.6, “Optimizer Statistics”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
flush_rewrite_rules()
</h3>
<dl>
<dt>
<a class="xref" href="rewriter-query-rewrite-plugin-reference.html#rewriter-query-rewrite-plugin-routines" title="7.6.4.3.2 Rewriter Query Rewrite Plugin Procedures and Functions">
Section 7.6.4.3.2, “Rewriter Query Rewrite Plugin Procedures and Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
FORMAT()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="locale-support.html" title="12.16 MySQL Server Locale Support">
Section 12.16, “MySQL Server Locale Support”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
FORMAT_BYTES()
</h3>
<dl>
<dt>
<a class="xref" href="performance-schema-functions.html" title="14.21 Performance Schema Functions">
Section 14.21, “Performance Schema Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="sys-format-bytes.html" title="30.4.5.3 The format_bytes() Function">
Section 30.4.5.3, “The format_bytes() Function”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
FORMAT_PICO_TIME()
</h3>
<dl>
<dt>
<a class="xref" href="performance-schema-functions.html" title="14.21 Performance Schema Functions">
Section 14.21, “Performance Schema Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="sys-format-time.html" title="30.4.5.6 The format_time() Function">
Section 30.4.5.6, “The format_time() Function”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
FOUND_ROWS()
</h3>
<dl>
<dt>
<a class="xref" href="replication-sbr-rbr.html" title="19.2.1.1 Advantages and Disadvantages of Statement-Based and Row-Based Replication">
Section 19.2.1.1, “Advantages and Disadvantages of Statement-Based and Row-Based
Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="binary-log-mixed.html" title="7.4.4.3 Mixed Binary Logging Format">
Section 7.4.4.3, “Mixed Binary Logging Format”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-functions.html" title="19.5.1.14 Replication and System Functions">
Section 19.5.1.14, “Replication and System Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="select.html" title="15.2.13 SELECT Statement">
Section 15.2.13, “SELECT Statement”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
FROM_BASE64()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
FROM_DAYS()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
FROM_UNIXTIME()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="error-log-format.html" title="7.4.2.9 Error Log Output Format">
Section 7.4.2.9, “Error Log Output Format”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="timestamp-lookups.html" title="10.3.14 Indexed Lookups from TIMESTAMP Columns">
Section 10.3.14, “Indexed Lookups from TIMESTAMP Columns”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-timezone.html" title="19.5.1.33 Replication and Time Zones">
Section 19.5.1.33, “Replication and Time Zones”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-G">
</a>
<h3 class="title">
G
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
gen_blacklist()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-plugin-functions.html" title="8.5.3.4 MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions">
Section 8.5.3.4, “MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
gen_blocklist()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-functions.html" title="8.5.3.4 MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions">
Section 8.5.3.4, “MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-usage.html" title="8.5.3.2 Using the MySQL Enterprise Data Masking and De-Identification Plugin">
Section 8.5.3.2, “Using the MySQL Enterprise Data Masking and De-Identification Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
gen_dictionary()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-functions.html" title="8.5.3.4 MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions">
Section 8.5.3.4, “MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-usage.html" title="8.5.3.2 Using the MySQL Enterprise Data Masking and De-Identification Plugin">
Section 8.5.3.2, “Using the MySQL Enterprise Data Masking and De-Identification Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
gen_dictionary_drop()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-plugin-functions.html" title="8.5.3.4 MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions">
Section 8.5.3.4, “MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
gen_dictionary_load()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-plugin-functions.html" title="8.5.3.4 MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions">
Section 8.5.3.4, “MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-usage.html" title="8.5.3.2 Using the MySQL Enterprise Data Masking and De-Identification Plugin">
Section 8.5.3.2, “Using the MySQL Enterprise Data Masking and De-Identification Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
gen_range()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-functions.html" title="8.5.3.4 MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions">
Section 8.5.3.4, “MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-usage.html" title="8.5.3.2 Using the MySQL Enterprise Data Masking and De-Identification Plugin">
Section 8.5.3.2, “Using the MySQL Enterprise Data Masking and De-Identification Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
gen_rnd_canada_sin()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
gen_rnd_email()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-components-vs-plugin.html" title="8.5.1 Data-Masking Components Versus the Data-Masking Plugin">
Section 8.5.1, “Data-Masking Components Versus the Data-Masking Plugin”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-functions.html" title="8.5.3.4 MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions">
Section 8.5.3.4, “MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-usage.html" title="8.5.3.2 Using the MySQL Enterprise Data Masking and De-Identification Plugin">
Section 8.5.3.2, “Using the MySQL Enterprise Data Masking and De-Identification Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
gen_rnd_iban()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
gen_rnd_pan()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-functions.html" title="8.5.3.4 MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions">
Section 8.5.3.4, “MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-usage.html" title="8.5.3.2 Using the MySQL Enterprise Data Masking and De-Identification Plugin">
Section 8.5.3.2, “Using the MySQL Enterprise Data Masking and De-Identification Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
gen_rnd_ssn()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-functions.html" title="8.5.3.4 MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions">
Section 8.5.3.4, “MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-usage.html" title="8.5.3.2 Using the MySQL Enterprise Data Masking and De-Identification Plugin">
Section 8.5.3.2, “Using the MySQL Enterprise Data Masking and De-Identification Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
gen_rnd_uk_nin()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
gen_rnd_us_phone()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-functions.html" title="8.5.3.4 MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions">
Section 8.5.3.4, “MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-usage.html" title="8.5.3.2 Using the MySQL Enterprise Data Masking and De-Identification Plugin">
Section 8.5.3.2, “Using the MySQL Enterprise Data Masking and De-Identification Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
gen_rnd_uuid()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
GeomCollection()
</h3>
<dl>
<dt>
<a class="xref" href="gis-mysql-specific-functions.html" title="14.16.5 MySQL-Specific Functions That Create Geometry Values">
Section 14.16.5, “MySQL-Specific Functions That Create Geometry Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
GeometryCollection()
</h3>
<dl>
<dt>
<a class="xref" href="gis-format-conversion-functions.html" title="14.16.6 Geometry Format Conversion Functions">
Section 14.16.6, “Geometry Format Conversion Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="gis-mysql-specific-functions.html" title="14.16.5 MySQL-Specific Functions That Create Geometry Values">
Section 14.16.5, “MySQL-Specific Functions That Create Geometry Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
GET_DD_COLUMN_PRIVILEGES()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
GET_DD_CREATE_OPTIONS()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
GET_DD_INDEX_SUB_PART_LENGTH()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
GET_FORMAT()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="locale-support.html" title="12.16 MySQL Server Locale Support">
Section 12.16, “MySQL Server Locale Support”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
GET_LOCK()
</h3>
<dl>
<dt>
<a class="xref" href="replication-sbr-rbr.html" title="19.2.1.1 Advantages and Disadvantages of Statement-Based and Row-Based Replication">
Section 19.2.1.1, “Advantages and Disadvantages of Statement-Based and Row-Based
Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-event.html" title="15.1.13 CREATE EVENT Statement">
Section 15.1.13, “CREATE EVENT Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="events-overview.html" title="27.4.1 Event Scheduler Overview">
Section 27.4.1, “Event Scheduler Overview”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="general-thread-states.html" title="10.14.3 General Thread States">
Section 10.14.3, “General Thread States”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-limitations.html" title="20.3.2 Group Replication Limitations">
Section 20.3.2, “Group Replication Limitations”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="internal-locking.html" title="10.11.1 Internal Locking Methods">
Section 10.11.1, “Internal Locking Methods”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="kill.html" title="15.7.8.4 KILL Statement">
Section 15.7.8.4, “KILL Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mysql-cluster-limitations-multiple-nodes.html" title="25.2.7.10 Limitations Relating to Multiple NDB Cluster Nodes">
Section 25.2.7.10, “Limitations Relating to Multiple NDB Cluster Nodes”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="lock-tables.html" title="15.3.6 LOCK TABLES and UNLOCK TABLES Statements">
Section 15.3.6, “LOCK TABLES and UNLOCK TABLES Statements”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="locking-functions.html" title="14.14 Locking Functions">
Section 14.14, “Locking Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="metadata-locking.html" title="10.11.4 Metadata Locking">
Section 10.11.4, “Metadata Locking”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-functions.html" title="19.5.1.14 Replication and System Functions">
Section 19.5.1.14, “Replication and System Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="locking-service.html" title="7.6.9.1 The Locking Service">
Section 7.6.9.1, “The Locking Service”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="locking-service.html#locking-service-interface" title="7.6.9.1.2 The Locking Service Function Interface">
Section 7.6.9.1.2, “The Locking Service Function Interface”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-metadata-locks-table.html" title="29.12.13.3 The metadata_locks Table">
Section 29.12.13.3, “The metadata_locks Table”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="sys-ps-setup-save.html" title="30.4.4.14 The ps_setup_save() Procedure">
Section 30.4.4.14, “The ps_setup_save() Procedure”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
getrusage()
</h3>
<dl>
<dt>
<a class="xref" href="mysql-cluster-ndbinfo-threadstat.html" title="25.6.17.64 The ndbinfo threadstat Table">
Section 25.6.17.64, “The ndbinfo threadstat Table”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
gettimeofday()
</h3>
<dl>
<dt>
<a class="xref" href="mysql-cluster-ndbinfo-threadstat.html" title="25.6.17.64 The ndbinfo threadstat Table">
Section 25.6.17.64, “The ndbinfo threadstat Table”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
GREATEST()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="comparison-operators.html" title="14.4.2 Comparison Functions and Operators">
Section 14.4.2, “Comparison Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
GROUP_CONCAT()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="internal-temporary-tables.html" title="10.4.4 Internal Temporary Table Use in MySQL">
Section 10.4.4, “Internal Temporary Table Use in MySQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="known-issues.html" title="B.3.7 Known Issues in MySQL">
Section B.3.7, “Known Issues in MySQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="features.html" title="1.2.2 The Main Features of MySQL">
Section 1.2.2, “The Main Features of MySQL”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
group_replication_disable_member_action
</h3>
<dl>
<dt>
<a class="xref" href="replication-asynchronous-connection-failover-replica.html" title="19.4.9.2 Asynchronous Connection Failover for Replicas">
Section 19.4.9.2, “Asynchronous Connection Failover for Replicas”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-functions-async-failover.html" title="14.18.3 Asynchronous Replication Channel Failover Functions">
Section 14.18.3, “Asynchronous Replication Channel Failover Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-member-actions.html" title="20.5.1.5 Configuring Member Actions">
Section 20.5.1.5, “Configuring Member Actions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-functions-for-member-actions.html" title="14.18.1.5 Functions to Set and Reset Group Replication Member Actions">
Section 14.18.1.5, “Functions to Set and Reset Group Replication Member Actions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-asynchronous-connection-failover.html" title="19.4.9 Switching Sources and Replicas with Asynchronous Connection Failover">
Section 19.4.9, “Switching Sources and Replicas with Asynchronous Connection Failover”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
group_replication_disable_member_action()
</h3>
<dl>
<dt>
<a class="xref" href="change-replication-source-to.html" title="15.4.2.2 CHANGE REPLICATION SOURCE TO Statement">
Section 15.4.2.2, “CHANGE REPLICATION SOURCE TO Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-member-actions.html" title="20.5.1.5 Configuring Member Actions">
Section 20.5.1.5, “Configuring Member Actions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-functions-for-member-actions.html" title="14.18.1.5 Functions to Set and Reset Group Replication Member Actions">
Section 14.18.1.5, “Functions to Set and Reset Group Replication Member Actions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-replication-group-configuration-version-table.html" title="29.12.11.12 The replication_group_configuration_version Table">
Section 29.12.11.12, “The replication_group_configuration_version Table”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-replication-group-member-actions-table.html" title="29.12.11.14 The replication_group_member_actions Table">
Section 29.12.11.14, “The replication_group_member_actions Table”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
group_replication_enable_member_action
</h3>
<dl>
<dt>
<a class="xref" href="group-replication-member-actions.html" title="20.5.1.5 Configuring Member Actions">
Section 20.5.1.5, “Configuring Member Actions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-functions-for-member-actions.html" title="14.18.1.5 Functions to Set and Reset Group Replication Member Actions">
Section 14.18.1.5, “Functions to Set and Reset Group Replication Member Actions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
group_replication_enable_member_action()
</h3>
<dl>
<dt>
<a class="xref" href="group-replication-functions-for-member-actions.html" title="14.18.1.5 Functions to Set and Reset Group Replication Member Actions">
Section 14.18.1.5, “Functions to Set and Reset Group Replication Member Actions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-replication-group-configuration-version-table.html" title="29.12.11.12 The replication_group_configuration_version Table">
Section 29.12.11.12, “The replication_group_configuration_version Table”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-replication-group-member-actions-table.html" title="29.12.11.14 The replication_group_member_actions Table">
Section 29.12.11.14, “The replication_group_member_actions Table”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
group_replication_get_communication_protocol()
</h3>
<dl>
<dt>
<a class="xref" href="group-replication-functions-for-communication-protocol.html" title="14.18.1.4 Functions to Inspect and Set the Group Replication Communication Protocol Version">
Section 14.18.1.4, “Functions to Inspect and Set the Group Replication Communication
Protocol Version”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-system-variables.html" title="20.9.1 Group Replication System Variables">
Section 20.9.1, “Group Replication System Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-performance-message-fragmentation.html" title="20.7.5 Message Fragmentation">
Section 20.7.5, “Message Fragmentation”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-communication-protocol.html" title="20.5.1.4 Setting a Group's Communication Protocol Version">
Section 20.5.1.4, “Setting a Group's Communication Protocol Version”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-single-consensus-leader.html" title="20.7.3 Single Consensus Leader">
Section 20.7.3, “Single Consensus Leader”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
group_replication_get_write_concurrency()
</h3>
<dl>
<dt>
<a class="xref" href="group-replication-functions-for-maximum-consensus.html" title="14.18.1.3 Functions to Inspect and Configure the Maximum Consensus Instances of a Group">
Section 14.18.1.3, “Functions to Inspect and Configure the Maximum Consensus Instances of a
Group”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-group-write-consensus.html" title="20.5.1.3 Using Group Replication Group Write Consensus">
Section 20.5.1.3, “Using Group Replication Group Write Consensus”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
group_replication_reset_member_actions
</h3>
<dl>
<dt>
<a class="xref" href="group-replication-member-actions.html" title="20.5.1.5 Configuring Member Actions">
Section 20.5.1.5, “Configuring Member Actions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-functions-for-member-actions.html" title="14.18.1.5 Functions to Set and Reset Group Replication Member Actions">
Section 14.18.1.5, “Functions to Set and Reset Group Replication Member Actions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
group_replication_reset_member_actions()
</h3>
<dl>
<dt>
<a class="xref" href="group-replication-functions-for-member-actions.html" title="14.18.1.5 Functions to Set and Reset Group Replication Member Actions">
Section 14.18.1.5, “Functions to Set and Reset Group Replication Member Actions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-replication-group-configuration-version-table.html" title="29.12.11.12 The replication_group_configuration_version Table">
Section 29.12.11.12, “The replication_group_configuration_version Table”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-replication-group-member-actions-table.html" title="29.12.11.14 The replication_group_member_actions Table">
Section 29.12.11.14, “The replication_group_member_actions Table”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
group_replication_set_as_primary()
</h3>
<dl>
<dt>
<a class="xref" href="group-replication-change-primary.html" title="20.5.1.1 Changing the Primary">
Section 20.5.1.1, “Changing the Primary”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-functions-for-new-primary.html" title="14.18.1.1 Function which Configures Group Replication Primary">
Section 14.18.1.1, “Function which Configures Group Replication Primary”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-online-upgrade-methods.html" title="20.8.3.3 Group Replication Online Upgrade Methods">
Section 20.8.3.3, “Group Replication Online Upgrade Methods”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-compatibility-upgrade.html" title="20.8.1.1 Member Versions During Upgrades">
Section 20.8.1.1, “Member Versions During Upgrades”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-single-primary-mode.html" title="20.1.3.1 Single-Primary Mode">
Section 20.1.3.1, “Single-Primary Mode”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-understanding-consistency-guarantees.html" title="20.5.3.1 Understanding Transaction Consistency Guarantees">
Section 20.5.3.1, “Understanding Transaction Consistency Guarantees”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mysql-nutshell.html" title="1.4 What Is New in MySQL 8.4 since MySQL 8.0">
Section 1.4, “What Is New in MySQL 8.4 since MySQL 8.0”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
group_replication_set_communication_protocol()
</h3>
<dl>
<dt>
<a class="xref" href="group-replication-functions-for-communication-protocol.html" title="14.18.1.4 Functions to Inspect and Set the Group Replication Communication Protocol Version">
Section 14.18.1.4, “Functions to Inspect and Set the Group Replication Communication
Protocol Version”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-offline-upgrade.html" title="20.8.2 Group Replication Offline Upgrade">
Section 20.8.2, “Group Replication Offline Upgrade”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-system-variables.html" title="20.9.1 Group Replication System Variables">
Section 20.9.1, “Group Replication System Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-performance-message-fragmentation.html" title="20.7.5 Message Fragmentation">
Section 20.7.5, “Message Fragmentation”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="privileges-provided.html" title="8.2.2 Privileges Provided by MySQL">
Section 8.2.2, “Privileges Provided by MySQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-communication-protocol.html" title="20.5.1.4 Setting a Group's Communication Protocol Version">
Section 20.5.1.4, “Setting a Group's Communication Protocol Version”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-single-consensus-leader.html" title="20.7.3 Single Consensus Leader">
Section 20.7.3, “Single Consensus Leader”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
group_replication_set_write_concurrency()
</h3>
<dl>
<dt>
<a class="xref" href="group-replication-functions-for-maximum-consensus.html" title="14.18.1.3 Functions to Inspect and Configure the Maximum Consensus Instances of a Group">
Section 14.18.1.3, “Functions to Inspect and Configure the Maximum Consensus Instances of a
Group”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="privileges-provided.html" title="8.2.2 Privileges Provided by MySQL">
Section 8.2.2, “Privileges Provided by MySQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-group-write-consensus.html" title="20.5.1.3 Using Group Replication Group Write Consensus">
Section 20.5.1.3, “Using Group Replication Group Write Consensus”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
group_replication_switch_to_multi_primary_mode()
</h3>
<dl>
<dt>
<a class="xref" href="group-replication-changing-group-mode.html" title="20.5.1.2 Changing the Group Mode">
Section 20.5.1.2, “Changing the Group Mode”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-online-upgrade-combining-versions.html" title="20.8.1 Combining Different Member Versions in a Group">
Section 20.8.1, “Combining Different Member Versions in a Group”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-functions-for-mode.html" title="14.18.1.2 Functions which Configure the Group Replication Mode">
Section 14.18.1.2, “Functions which Configure the Group Replication Mode”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-system-variables.html" title="20.9.1 Group Replication System Variables">
Section 20.9.1, “Group Replication System Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-deploying-in-multi-primary-or-single-primary-mode.html" title="20.1.3 Multi-Primary and Single-Primary Modes">
Section 20.1.3, “Multi-Primary and Single-Primary Modes”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-multi-primary-mode.html#group-replication-multi-primary-compatibility" title="20.1.3.2.3 Version Compatibility">
Section 20.1.3.2.3, “Version Compatibility”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
group_replication_switch_to_single_primary_mode()
</h3>
<dl>
<dt>
<a class="xref" href="group-replication-changing-group-mode.html" title="20.5.1.2 Changing the Group Mode">
Section 20.5.1.2, “Changing the Group Mode”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-functions-for-mode.html" title="14.18.1.2 Functions which Configure the Group Replication Mode">
Section 14.18.1.2, “Functions which Configure the Group Replication Mode”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-system-variables.html" title="20.9.1 Group Replication System Variables">
Section 20.9.1, “Group Replication System Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-deploying-in-multi-primary-or-single-primary-mode.html" title="20.1.3 Multi-Primary and Single-Primary Modes">
Section 20.1.3, “Multi-Primary and Single-Primary Modes”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-replication-single-primary-mode.html" title="20.1.3.1 Single-Primary Mode">
Section 20.1.3.1, “Single-Primary Mode”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
GROUPING()
</h3>
<dl>
<dt>
<a class="xref" href="group-by-modifiers.html" title="14.19.2 GROUP BY Modifiers">
Section 14.19.2, “GROUP BY Modifiers”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="window-functions-usage.html" title="14.20.2 Window Function Concepts and Syntax">
Section 14.20.2, “Window Function Concepts and Syntax”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
GTID_SUBSET()
</h3>
<dl>
<dt>
<a class="xref" href="gtid-functions.html" title="14.18.2 Functions Used with Global Transaction Identifiers (GTIDs)">
Section 14.18.2, “Functions Used with Global Transaction Identifiers (GTIDs)”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-gtids-concepts.html" title="19.1.3.1 GTID Format and Storage">
Section 19.1.3.1, “GTID Format and Storage”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-gtids-functions.html" title="19.1.3.8 Stored Function Examples to Manipulate GTIDs">
Section 19.1.3.8, “Stored Function Examples to Manipulate GTIDs”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mysql-nutshell.html" title="1.4 What Is New in MySQL 8.4 since MySQL 8.0">
Section 1.4, “What Is New in MySQL 8.4 since MySQL 8.0”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
GTID_SUBTRACT()
</h3>
<dl>
<dt>
<a class="xref" href="gtid-functions.html" title="14.18.2 Functions Used with Global Transaction Identifiers (GTIDs)">
Section 14.18.2, “Functions Used with Global Transaction Identifiers (GTIDs)”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-options-gtids.html" title="19.1.6.5 Global Transaction ID System Variables">
Section 19.1.6.5, “Global Transaction ID System Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-gtids-concepts.html" title="19.1.3.1 GTID Format and Storage">
Section 19.1.3.1, “GTID Format and Storage”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-gtids-functions.html" title="19.1.3.8 Stored Function Examples to Manipulate GTIDs">
Section 19.1.3.8, “Stored Function Examples to Manipulate GTIDs”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mysql-nutshell.html" title="1.4 What Is New in MySQL 8.4 since MySQL 8.0">
Section 1.4, “What Is New in MySQL 8.4 since MySQL 8.0”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-H">
</a>
<h3 class="title">
H
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
HEX()
</h3>
<dl>
<dt>
<a class="xref" href="bit-value-literals.html" title="11.1.5 Bit-Value Literals">
Section 11.1.5, “Bit-Value Literals”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-literal.html" title="12.3.6 Character String Literal Character Set and Collation">
Section 12.3.6, “Character String Literal Character Set and Collation”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="keyring-functions-general-purpose.html" title="8.4.4.12 General-Purpose Keyring Key-Management Functions">
Section 8.4.4.12, “General-Purpose Keyring Key-Management Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="hexadecimal-literals.html" title="11.1.4 Hexadecimal Literals">
Section 11.1.4, “Hexadecimal Literals”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
HOUR()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-I">
</a>
<h3 class="title">
I
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ICU_VERSION()
</h3>
<dl>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
IF
</h3>
<dl>
<dt>
<a class="xref" href="prepare.html" title="15.5.1 PREPARE Statement">
Section 15.5.1, “PREPARE Statement”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
IF()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="flow-control-functions.html" title="14.5 Flow Control Functions">
Section 14.5, “Flow Control Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="if.html" title="15.6.5.2 IF Statement">
Section 15.6.5.2, “IF Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="innodb-information-schema-system-tables.html" title="17.15.3 InnoDB INFORMATION_SCHEMA Schema Object Tables">
Section 17.15.3, “InnoDB INFORMATION_SCHEMA Schema Object Tables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="known-issues.html" title="B.3.7 Known Issues in MySQL">
Section B.3.7, “Known Issues in MySQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
IFNULL
</h3>
<dl>
<dt>
<a class="xref" href="prepare.html" title="15.5.1 PREPARE Statement">
Section 15.5.1, “PREPARE Statement”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
IFNULL()
</h3>
<dl>
<dt>
<a class="xref" href="flow-control-functions.html" title="14.5 Flow Control Functions">
Section 14.5, “Flow Control Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="problems-with-null.html" title="B.3.4.3 Problems with NULL Values">
Section B.3.4.3, “Problems with NULL Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INET6_ATON()
</h3>
<dl>
<dt>
<a class="xref" href="ipv6-support.html" title="7.1.13 IPv6 Support">
Section 7.1.13, “IPv6 Support”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INET6_NTOA()
</h3>
<dl>
<dt>
<a class="xref" href="ipv6-support.html" title="7.1.13 IPv6 Support">
Section 7.1.13, “IPv6 Support”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INET_ATON()
</h3>
<dl>
<dt>
<a class="xref" href="ipv6-support.html" title="7.1.13 IPv6 Support">
Section 7.1.13, “IPv6 Support”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INET_NTOA()
</h3>
<dl>
<dt>
<a class="xref" href="ipv6-support.html" title="7.1.13 IPv6 Support">
Section 7.1.13, “IPv6 Support”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INSERT()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INSTR()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_AUTO_INCREMENT()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_AVG_ROW_LENGTH()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_CHECK_TIME()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_CHECKSUM()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_DATA_FREE()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_DATA_LENGTH()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_DD_CHAR_LENGTH()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_GET_COMMENT_OR_ERROR()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_GET_ENABLED_ROLE_JSON()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_GET_HOSTNAME()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_GET_USERNAME()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_GET_VIEW_WARNING_OR_ERROR()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_INDEX_COLUMN_CARDINALITY()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_INDEX_LENGTH()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_IS_ENABLED_ROLE()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_IS_MANDATORY_ROLE()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_KEYS_DISABLED()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_MAX_DATA_LENGTH()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_TABLE_ROWS()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERNAL_UPDATE_TIME()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
INTERVAL()
</h3>
<dl>
<dt>
<a class="xref" href="comparison-operators.html" title="14.4.2 Comparison Functions and Operators">
Section 14.4.2, “Comparison Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
IS_FREE_LOCK()
</h3>
<dl>
<dt>
<a class="xref" href="replication-sbr-rbr.html" title="19.2.1.1 Advantages and Disadvantages of Statement-Based and Row-Based Replication">
Section 19.2.1.1, “Advantages and Disadvantages of Statement-Based and Row-Based
Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="locking-functions.html" title="14.14 Locking Functions">
Section 14.14, “Locking Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-functions.html" title="19.5.1.14 Replication and System Functions">
Section 19.5.1.14, “Replication and System Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
IS_IPV4()
</h3>
<dl>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
IS_IPV4_COMPAT()
</h3>
<dl>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
IS_IPV4_MAPPED()
</h3>
<dl>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
IS_IPV6()
</h3>
<dl>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
IS_USED_LOCK()
</h3>
<dl>
<dt>
<a class="xref" href="replication-sbr-rbr.html" title="19.2.1.1 Advantages and Disadvantages of Statement-Based and Row-Based Replication">
Section 19.2.1.1, “Advantages and Disadvantages of Statement-Based and Row-Based
Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="locking-functions.html" title="14.14 Locking Functions">
Section 14.14, “Locking Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-functions.html" title="19.5.1.14 Replication and System Functions">
Section 19.5.1.14, “Replication and System Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
IS_UUID()
</h3>
<dl>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
IS_VISIBLE_DD_OBJECT()
</h3>
<dl>
<dt>
<a class="xref" href="internal-functions.html" title="14.22 Internal Functions">
Section 14.22, “Internal Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ISNULL()
</h3>
<dl>
<dt>
<a class="xref" href="comparison-operators.html" title="14.4.2 Comparison Functions and Operators">
Section 14.4.2, “Comparison Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-J">
</a>
<h3 class="title">
J
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_ARRAY()
</h3>
<dl>
<dt>
<a class="xref" href="json-creation-functions.html" title="14.17.2 Functions That Create JSON Values">
Section 14.17.2, “Functions That Create JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-search-functions.html" title="14.17.3 Functions That Search JSON Values">
Section 14.17.3, “Functions That Search JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_ARRAY_APPEND()
</h3>
<dl>
<dt>
<a class="xref" href="json-modification-functions.html" title="14.17.4 Functions That Modify JSON Values">
Section 14.17.4, “Functions That Modify JSON Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_ARRAY_INSERT()
</h3>
<dl>
<dt>
<a class="xref" href="json-modification-functions.html" title="14.17.4 Functions That Modify JSON Values">
Section 14.17.4, “Functions That Modify JSON Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_ARRAYAGG()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-creation-functions.html" title="14.17.2 Functions That Create JSON Values">
Section 14.17.2, “Functions That Create JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-function-reference.html" title="14.17.1 JSON Function Reference">
Section 14.17.1, “JSON Function Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_CONTAINS()
</h3>
<dl>
<dt>
<a class="xref" href="create-index.html" title="15.1.15 CREATE INDEX Statement">
Section 15.1.15, “CREATE INDEX Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-search-functions.html" title="14.17.3 Functions That Search JSON Values">
Section 14.17.3, “Functions That Search JSON Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_CONTAINS_PATH()
</h3>
<dl>
<dt>
<a class="xref" href="json-search-functions.html" title="14.17.3 Functions That Search JSON Values">
Section 14.17.3, “Functions That Search JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_DEPTH()
</h3>
<dl>
<dt>
<a class="xref" href="json-attribute-functions.html" title="14.17.5 Functions That Return JSON Value Attributes">
Section 14.17.5, “Functions That Return JSON Value Attributes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_EXTRACT()
</h3>
<dl>
<dt>
<a class="xref" href="explain.html" title="15.8.2 EXPLAIN Statement">
Section 15.8.2, “EXPLAIN Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-search-functions.html" title="14.17.3 Functions That Search JSON Values">
Section 14.17.3, “Functions That Search JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-validation-functions.html" title="14.17.7 JSON Schema Validation Functions">
Section 14.17.7, “JSON Schema Validation Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-table-secondary-indexes.html" title="15.1.20.9 Secondary Indexes and Generated Columns">
Section 15.1.20.9, “Secondary Indexes and Generated Columns”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_INSERT()
</h3>
<dl>
<dt>
<a class="xref" href="json-modification-functions.html" title="14.17.4 Functions That Modify JSON Values">
Section 14.17.4, “Functions That Modify JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_KEYS()
</h3>
<dl>
<dt>
<a class="xref" href="json-search-functions.html" title="14.17.3 Functions That Search JSON Values">
Section 14.17.3, “Functions That Search JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="grant-tables.html" title="8.2.3 Grant Tables">
Section 8.2.3, “Grant Tables”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_LENGTH()
</h3>
<dl>
<dt>
<a class="xref" href="json-attribute-functions.html" title="14.17.5 Functions That Return JSON Value Attributes">
Section 14.17.5, “Functions That Return JSON Value Attributes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_MERGE()
</h3>
<dl>
<dt>
<a class="xref" href="json-modification-functions.html" title="14.17.4 Functions That Modify JSON Values">
Section 14.17.4, “Functions That Modify JSON Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_MERGE_PATCH()
</h3>
<dl>
<dt>
<a class="xref" href="alter-user.html" title="15.7.1.1 ALTER USER Statement">
Section 15.7.1.1, “ALTER USER Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-modification-functions.html" title="14.17.4 Functions That Modify JSON Values">
Section 14.17.4, “Functions That Modify JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_MERGE_PRESERVE()
</h3>
<dl>
<dt>
<a class="xref" href="json-modification-functions.html" title="14.17.4 Functions That Modify JSON Values">
Section 14.17.4, “Functions That Modify JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_OBJECT()
</h3>
<dl>
<dt>
<a class="xref" href="json-creation-functions.html" title="14.17.2 Functions That Create JSON Values">
Section 14.17.2, “Functions That Create JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-search-functions.html" title="14.17.3 Functions That Search JSON Values">
Section 14.17.3, “Functions That Search JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_OBJECTAGG()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-creation-functions.html" title="14.17.2 Functions That Create JSON Values">
Section 14.17.2, “Functions That Create JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-function-reference.html" title="14.17.1 JSON Function Reference">
Section 14.17.1, “JSON Function Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_OVERLAPS()
</h3>
<dl>
<dt>
<a class="xref" href="create-index.html" title="15.1.15 CREATE INDEX Statement">
Section 15.1.15, “CREATE INDEX Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-search-functions.html" title="14.17.3 Functions That Search JSON Values">
Section 14.17.3, “Functions That Search JSON Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_PRETTY()
</h3>
<dl>
<dt>
<a class="xref" href="json-function-reference.html" title="14.17.1 JSON Function Reference">
Section 14.17.1, “JSON Function Reference”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-validation-functions.html" title="14.17.7 JSON Schema Validation Functions">
Section 14.17.7, “JSON Schema Validation Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-utility-functions.html" title="14.17.8 JSON Utility Functions">
Section 14.17.8, “JSON Utility Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_QUOTE()
</h3>
<dl>
<dt>
<a class="xref" href="json-creation-functions.html" title="14.17.2 Functions That Create JSON Values">
Section 14.17.2, “Functions That Create JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-utility-functions.html" title="14.17.8 JSON Utility Functions">
Section 14.17.8, “JSON Utility Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_REMOVE()
</h3>
<dl>
<dt>
<a class="xref" href="replication-options-binary-log.html" title="19.1.6.4 Binary Logging Options and Variables">
Section 19.1.6.4, “Binary Logging Options and Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-modification-functions.html" title="14.17.4 Functions That Modify JSON Values">
Section 14.17.4, “Functions That Modify JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-utility-functions.html" title="14.17.8 JSON Utility Functions">
Section 14.17.8, “JSON Utility Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_REPLACE()
</h3>
<dl>
<dt>
<a class="xref" href="replication-options-binary-log.html" title="19.1.6.4 Binary Logging Options and Variables">
Section 19.1.6.4, “Binary Logging Options and Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-modification-functions.html" title="14.17.4 Functions That Modify JSON Values">
Section 14.17.4, “Functions That Modify JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-utility-functions.html" title="14.17.8 JSON Utility Functions">
Section 14.17.8, “JSON Utility Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_SCHEMA_VALID()
</h3>
<dl>
<dt>
<a class="xref" href="json-validation-functions.html" title="14.17.7 JSON Schema Validation Functions">
Section 14.17.7, “JSON Schema Validation Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_SCHEMA_VALIDATION_REPORT()
</h3>
<dl>
<dt>
<a class="xref" href="json-validation-functions.html" title="14.17.7 JSON Schema Validation Functions">
Section 14.17.7, “JSON Schema Validation Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_SEARCH()
</h3>
<dl>
<dt>
<a class="xref" href="json-search-functions.html" title="14.17.3 Functions That Search JSON Values">
Section 14.17.3, “Functions That Search JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_SET()
</h3>
<dl>
<dt>
<a class="xref" href="replication-options-binary-log.html" title="19.1.6.4 Binary Logging Options and Variables">
Section 19.1.6.4, “Binary Logging Options and Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-modification-functions.html" title="14.17.4 Functions That Modify JSON Values">
Section 14.17.4, “Functions That Modify JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-utility-functions.html" title="14.17.8 JSON Utility Functions">
Section 14.17.8, “JSON Utility Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_STORAGE_FREE()
</h3>
<dl>
<dt>
<a class="xref" href="json-function-reference.html" title="14.17.1 JSON Function Reference">
Section 14.17.1, “JSON Function Reference”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-utility-functions.html" title="14.17.8 JSON Utility Functions">
Section 14.17.8, “JSON Utility Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_STORAGE_SIZE()
</h3>
<dl>
<dt>
<a class="xref" href="json-function-reference.html" title="14.17.1 JSON Function Reference">
Section 14.17.1, “JSON Function Reference”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-utility-functions.html" title="14.17.8 JSON Utility Functions">
Section 14.17.8, “JSON Utility Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_TABLE()
</h3>
<dl>
<dt>
<a class="xref" href="derived-tables.html" title="15.2.15.8 Derived Tables">
Section 15.2.15.8, “Derived Tables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-table-functions.html" title="14.17.6 JSON Table Functions">
Section 14.17.6, “JSON Table Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="lateral-derived-tables.html" title="15.2.15.9 Lateral Derived Tables">
Section 15.2.15.9, “Lateral Derived Tables”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_TYPE()
</h3>
<dl>
<dt>
<a class="xref" href="json-attribute-functions.html" title="14.17.5 Functions That Return JSON Value Attributes">
Section 14.17.5, “Functions That Return JSON Value Attributes”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-search-functions.html" title="14.17.3 Functions That Search JSON Values">
Section 14.17.3, “Functions That Search JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_UNQUOTE(
</h3>
<dl>
<dt>
<a class="xref" href="json-search-functions.html" title="14.17.3 Functions That Search JSON Values">
Section 14.17.3, “Functions That Search JSON Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_UNQUOTE()
</h3>
<dl>
<dt>
<a class="xref" href="create-index.html" title="15.1.15 CREATE INDEX Statement">
Section 15.1.15, “CREATE INDEX Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-modification-functions.html" title="14.17.4 Functions That Modify JSON Values">
Section 14.17.4, “Functions That Modify JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="generated-column-index-optimizations.html" title="10.3.11 Optimizer Use of Generated Column Indexes">
Section 10.3.11, “Optimizer Use of Generated Column Indexes”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-table-secondary-indexes.html" title="15.1.20.9 Secondary Indexes and Generated Columns">
Section 15.1.20.9, “Secondary Indexes and Generated Columns”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_VALID()
</h3>
<dl>
<dt>
<a class="xref" href="json-attribute-functions.html" title="14.17.5 Functions That Return JSON Value Attributes">
Section 14.17.5, “Functions That Return JSON Value Attributes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
JSON_VALUE()
</h3>
<dl>
<dt>
<a class="xref" href="cast-functions.html" title="14.10 Cast Functions and Operators">
Section 14.10, “Cast Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json-search-functions.html" title="14.17.3 Functions That Search JSON Values">
Section 14.17.3, “Functions That Search JSON Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-table-secondary-indexes.html" title="15.1.20.9 Secondary Indexes and Generated Columns">
Section 15.1.20.9, “Secondary Indexes and Generated Columns”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-K">
</a>
<h3 class="title">
K
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
keyring_aws_rotate_cmk()
</h3>
<dl>
<dt>
<a class="xref" href="keyring-functions-plugin-specific.html" title="8.4.4.13 Plugin-Specific Keyring Key-Management Functions">
Section 8.4.4.13, “Plugin-Specific Keyring Key-Management Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="keyring-aws-plugin.html" title="8.4.4.7 Using the keyring_aws Amazon Web Services Keyring Plugin">
Section 8.4.4.7, “Using the keyring_aws Amazon Web Services Keyring Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
keyring_aws_rotate_keys()
</h3>
<dl>
<dt>
<a class="xref" href="keyring-functions-plugin-specific.html" title="8.4.4.13 Plugin-Specific Keyring Key-Management Functions">
Section 8.4.4.13, “Plugin-Specific Keyring Key-Management Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="keyring-aws-plugin.html" title="8.4.4.7 Using the keyring_aws Amazon Web Services Keyring Plugin">
Section 8.4.4.7, “Using the keyring_aws Amazon Web Services Keyring Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
keyring_hashicorp_update_config()
</h3>
<dl>
<dt>
<a class="xref" href="keyring-functions-plugin-specific.html" title="8.4.4.13 Plugin-Specific Keyring Key-Management Functions">
Section 8.4.4.13, “Plugin-Specific Keyring Key-Management Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="keyring-hashicorp-plugin.html" title="8.4.4.8 Using the HashiCorp Vault Keyring Plugin">
Section 8.4.4.8, “Using the HashiCorp Vault Keyring Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
keyring_key_fetch()
</h3>
<dl>
<dt>
<a class="xref" href="keyring-functions-general-purpose.html" title="8.4.4.12 General-Purpose Keyring Key-Management Functions">
Section 8.4.4.12, “General-Purpose Keyring Key-Management Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
keyring_key_generate()
</h3>
<dl>
<dt>
<a class="xref" href="keyring-functions-general-purpose.html" title="8.4.4.12 General-Purpose Keyring Key-Management Functions">
Section 8.4.4.12, “General-Purpose Keyring Key-Management Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
keyring_key_length_fetch()
</h3>
<dl>
<dt>
<a class="xref" href="keyring-functions-general-purpose.html" title="8.4.4.12 General-Purpose Keyring Key-Management Functions">
Section 8.4.4.12, “General-Purpose Keyring Key-Management Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
keyring_key_remove()
</h3>
<dl>
<dt>
<a class="xref" href="keyring-functions-general-purpose.html" title="8.4.4.12 General-Purpose Keyring Key-Management Functions">
Section 8.4.4.12, “General-Purpose Keyring Key-Management Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
keyring_key_store()
</h3>
<dl>
<dt>
<a class="xref" href="keyring-functions-general-purpose.html" title="8.4.4.12 General-Purpose Keyring Key-Management Functions">
Section 8.4.4.12, “General-Purpose Keyring Key-Management Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
keyring_key_type_fetch()
</h3>
<dl>
<dt>
<a class="xref" href="keyring-functions-general-purpose.html" title="8.4.4.12 General-Purpose Keyring Key-Management Functions">
Section 8.4.4.12, “General-Purpose Keyring Key-Management Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-L">
</a>
<h3 class="title">
L
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LAG()
</h3>
<dl>
<dt>
<a class="xref" href="window-function-descriptions.html" title="14.20.1 Window Function Descriptions">
Section 14.20.1, “Window Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LAST_DAY()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LAST_INSERT_ID()
</h3>
<dl>
<dt>
<a class="xref" href="comparison-operators.html" title="14.4.2 Comparison Functions and Operators">
Section 14.4.2, “Comparison Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-table.html" title="15.1.20 CREATE TABLE Statement">
Section 15.1.20, “CREATE TABLE Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="insert-on-duplicate.html" title="15.2.7.2 INSERT ... ON DUPLICATE KEY UPDATE Statement">
Section 15.2.7.2, “INSERT ... ON DUPLICATE KEY UPDATE Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="insert.html" title="15.2.7 INSERT Statement">
Section 15.2.7, “INSERT Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="lock-tables.html" title="15.3.6 LOCK TABLES and UNLOCK TABLES Statements">
Section 15.3.6, “LOCK TABLES and UNLOCK TABLES Statements”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mysql-cluster-programs-ndb-restore.html" title="25.5.23 ndb_restore — Restore an NDB Cluster Backup">
Section 25.5.23, “ndb_restore — Restore an NDB Cluster Backup”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-auto-increment.html" title="19.5.1.1 Replication and AUTO_INCREMENT">
Section 19.5.1.1, “Replication and AUTO_INCREMENT”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-administration-skip.html#set-global-replica-sql-skip-counter" title="19.1.7.3.2.1 Skipping Transactions With SET GLOBAL sql_replica_skip_counter">
Section 19.1.7.3.2.1, “Skipping Transactions With
<code class="literal">
SET GLOBAL
sql_replica_skip_counter
</code>
”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="stored-routines-last-insert-id.html" title="27.2.4 Stored Procedures, Functions, Triggers, and LAST_INSERT_ID()">
Section 27.2.4, “Stored Procedures, Functions, Triggers, and LAST_INSERT_ID()”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-problems.html" title="19.5.4 Troubleshooting Replication">
Section 19.5.4, “Troubleshooting Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="view-updatability.html" title="27.5.3 Updatable and Insertable Views">
Section 27.5.3, “Updatable and Insertable Views”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="example-auto-increment.html" title="5.6.9 Using AUTO_INCREMENT">
Section 5.6.9, “Using AUTO_INCREMENT”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LAST_VALUE()
</h3>
<dl>
<dt>
<a class="xref" href="window-function-descriptions.html" title="14.20.1 Window Function Descriptions">
Section 14.20.1, “Window Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="window-functions-frames.html" title="14.20.3 Window Function Frame Specification">
Section 14.20.3, “Window Function Frame Specification”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LCASE()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LEAD()
</h3>
<dl>
<dt>
<a class="xref" href="window-function-descriptions.html" title="14.20.1 Window Function Descriptions">
Section 14.20.1, “Window Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LEAST()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="comparison-operators.html" title="14.4.2 Comparison Functions and Operators">
Section 14.4.2, “Comparison Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LEFT()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LENGTH()
</h3>
<dl>
<dt>
<a class="xref" href="storage-requirements.html" title="13.7 Data Type Storage Requirements">
Section 13.7, “Data Type Storage Requirements”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="gis-data-formats.html" title="13.4.3 Supported Spatial Data Formats">
Section 13.4.3, “Supported Spatial Data Formats”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LineString()
</h3>
<dl>
<dt>
<a class="xref" href="gis-mysql-specific-functions.html" title="14.16.5 MySQL-Specific Functions That Create Geometry Values">
Section 14.16.5, “MySQL-Specific Functions That Create Geometry Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LN()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LOAD_FILE()
</h3>
<dl>
<dt>
<a class="xref" href="replication-sbr-rbr.html" title="19.2.1.1 Advantages and Disadvantages of Statement-Based and Row-Based Replication">
Section 19.2.1.1, “Advantages and Disadvantages of Statement-Based and Row-Based
Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="load-xml.html" title="15.2.10 LOAD XML Statement">
Section 15.2.10, “LOAD XML Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="binary-log-mixed.html" title="7.4.4.3 Mixed Binary Logging Format">
Section 7.4.4.3, “Mixed Binary Logging Format”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="enterprise-encryption-usage.html" title="8.6.3 MySQL Enterprise Encryption Usage and Examples">
Section 8.6.3, “MySQL Enterprise Encryption Usage and Examples”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="privileges-provided.html" title="8.2.2 Privileges Provided by MySQL">
Section 8.2.2, “Privileges Provided by MySQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-functions.html" title="19.5.1.14 Replication and System Functions">
Section 19.5.1.14, “Replication and System Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
load_rewrite_rules()
</h3>
<dl>
<dt>
<a class="xref" href="rewriter-query-rewrite-plugin-reference.html#rewriter-query-rewrite-plugin-routines" title="7.6.4.3.2 Rewriter Query Rewrite Plugin Procedures and Functions">
Section 7.6.4.3.2, “Rewriter Query Rewrite Plugin Procedures and Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="rewriter-query-rewrite-plugin.html" title="7.6.4 The Rewriter Query Rewrite Plugin">
Section 7.6.4, “The Rewriter Query Rewrite Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LOCALTIME
</h3>
<dl>
<dt>
<a class="xref" href="timestamp-initialization.html" title="13.2.5 Automatic Initialization and Updating for TIMESTAMP and DATETIME">
Section 13.2.5, “Automatic Initialization and Updating for TIMESTAMP and DATETIME”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LOCALTIME()
</h3>
<dl>
<dt>
<a class="xref" href="timestamp-initialization.html" title="13.2.5 Automatic Initialization and Updating for TIMESTAMP and DATETIME">
Section 13.2.5, “Automatic Initialization and Updating for TIMESTAMP and DATETIME”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LOCALTIMESTAMP
</h3>
<dl>
<dt>
<a class="xref" href="timestamp-initialization.html" title="13.2.5 Automatic Initialization and Updating for TIMESTAMP and DATETIME">
Section 13.2.5, “Automatic Initialization and Updating for TIMESTAMP and DATETIME”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LOCALTIMESTAMP()
</h3>
<dl>
<dt>
<a class="xref" href="timestamp-initialization.html" title="13.2.5 Automatic Initialization and Updating for TIMESTAMP and DATETIME">
Section 13.2.5, “Automatic Initialization and Updating for TIMESTAMP and DATETIME”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LOCATE()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LOG()
</h3>
<dl>
<dt>
<a class="xref" href="partitioning-linear-hash.html" title="26.2.4.1 LINEAR HASH Partitioning">
Section 26.2.4.1, “LINEAR HASH Partitioning”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LOG10()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LOG2()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LOWER()
</h3>
<dl>
<dt>
<a class="xref" href="cast-functions.html" title="14.10 Cast Functions and Operators">
Section 14.10, “Cast Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-unicode-sets.html" title="12.10.1 Unicode Character Sets">
Section 12.10.1, “Unicode Character Sets”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-collation-information-schema.html" title="12.8.7 Using Collation in INFORMATION_SCHEMA Searches">
Section 12.8.7, “Using Collation in INFORMATION_SCHEMA Searches”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LPAD()
</h3>
<dl>
<dt>
<a class="xref" href="bit-functions.html" title="14.12 Bit Functions and Operators">
Section 14.12, “Bit Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="numeric-type-syntax.html" title="13.1.1 Numeric Data Type Syntax">
Section 13.1.1, “Numeric Data Type Syntax”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="numeric-type-attributes.html" title="13.1.6 Numeric Type Attributes">
Section 13.1.6, “Numeric Type Attributes”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
LTRIM()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-M">
</a>
<h3 class="title">
M
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MAKE_SET()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MAKEDATE()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MAKETIME()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
mask_canada_sin()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
mask_iban()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
mask_inner
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
mask_inner()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-components-vs-plugin.html" title="8.5.1 Data-Masking Components Versus the Data-Masking Plugin">
Section 8.5.1, “Data-Masking Components Versus the Data-Masking Plugin”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-functions.html" title="8.5.3.4 MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions">
Section 8.5.3.4, “MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-usage.html" title="8.5.3.2 Using the MySQL Enterprise Data Masking and De-Identification Plugin">
Section 8.5.3.2, “Using the MySQL Enterprise Data Masking and De-Identification Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
mask_outer
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
mask_outer()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-components-vs-plugin.html" title="8.5.1 Data-Masking Components Versus the Data-Masking Plugin">
Section 8.5.1, “Data-Masking Components Versus the Data-Masking Plugin”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-functions.html" title="8.5.3.4 MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions">
Section 8.5.3.4, “MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-usage.html" title="8.5.3.2 Using the MySQL Enterprise Data Masking and De-Identification Plugin">
Section 8.5.3.2, “Using the MySQL Enterprise Data Masking and De-Identification Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
mask_pan()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-functions.html" title="8.5.3.4 MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions">
Section 8.5.3.4, “MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-usage.html" title="8.5.3.2 Using the MySQL Enterprise Data Masking and De-Identification Plugin">
Section 8.5.3.2, “Using the MySQL Enterprise Data Masking and De-Identification Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
mask_pan_relaxed()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-functions.html" title="8.5.3.4 MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions">
Section 8.5.3.4, “MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-usage.html" title="8.5.3.2 Using the MySQL Enterprise Data Masking and De-Identification Plugin">
Section 8.5.3.2, “Using the MySQL Enterprise Data Masking and De-Identification Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
mask_ssn()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-functions.html" title="8.5.3.4 MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions">
Section 8.5.3.4, “MySQL Enterprise Data Masking and De-Identification Plugin Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-plugin-usage.html" title="8.5.3.2 Using the MySQL Enterprise Data Masking and De-Identification Plugin">
Section 8.5.3.2, “Using the MySQL Enterprise Data Masking and De-Identification Plugin”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
mask_uk_nin()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
mask_uuid()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-usage.html" title="8.5.2.2 Using MySQL Enterprise Data Masking and De-Identification Components">
Section 8.5.2.2, “Using MySQL Enterprise Data Masking and De-Identification Components”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
masking_dictionaries_flush()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mysql-nutshell.html" title="1.4 What Is New in MySQL 8.4 since MySQL 8.0">
Section 1.4, “What Is New in MySQL 8.4 since MySQL 8.0”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
masking_dictionary_remove()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="privileges-provided.html" title="8.2.2 Privileges Provided by MySQL">
Section 8.2.2, “Privileges Provided by MySQL”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
masking_dictionary_term_add()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="privileges-provided.html" title="8.2.2 Privileges Provided by MySQL">
Section 8.2.2, “Privileges Provided by MySQL”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
masking_dictionary_term_remove()
</h3>
<dl>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="privileges-provided.html" title="8.2.2 Privileges Provided by MySQL">
Section 8.2.2, “Privileges Provided by MySQL”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MASTER_POS_WAIT()
</h3>
<dl>
<dt>
<a class="xref" href="faqs-replication.html" title="A.14 MySQL 8.4 FAQ: Replication">
Section A.14, “MySQL 8.4 FAQ: Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-functions-synchronization.html" title="14.18.4 Position-Based Synchronization Functions">
Section 14.18.4, “Position-Based Synchronization Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MATCH
</h3>
<dl>
<dt>
<a class="xref" href="expressions.html" title="11.5 Expressions">
Section 11.5, “Expressions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MATCH ()
</h3>
<dl>
<dt>
<a class="xref" href="fulltext-search.html" title="14.9 Full-Text Search Functions">
Section 14.9, “Full-Text Search Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MATCH()
</h3>
<dl>
<dt>
<a class="xref" href="fulltext-boolean.html" title="14.9.2 Boolean Full-Text Searches">
Section 14.9.2, “Boolean Full-Text Searches”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="fulltext-fine-tuning.html" title="14.9.6 Fine-Tuning MySQL Full-Text Search">
Section 14.9.6, “Fine-Tuning MySQL Full-Text Search”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="fulltext-restrictions.html" title="14.9.5 Full-Text Restrictions">
Section 14.9.5, “Full-Text Restrictions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="fulltext-search.html" title="14.9 Full-Text Search Functions">
Section 14.9, “Full-Text Search Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-by-modifiers.html" title="14.19.2 GROUP BY Modifiers">
Section 14.19.2, “GROUP BY Modifiers”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="innodb-fulltext-index.html" title="17.6.2.4 InnoDB Full-Text Indexes">
Section 17.6.2.4, “InnoDB Full-Text Indexes”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="glossary.html" title="MySQL Glossary">
MySQL Glossary
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="fulltext-natural-language.html" title="14.9.1 Natural Language Full-Text Searches">
Section 14.9.1, “Natural Language Full-Text Searches”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MAX(
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MAX()
</h3>
<dl>
<dt>
<a class="xref" href="two-digit-years.html" title="13.2.9 2-Digit Years in Dates">
Section 13.2.9, “2-Digit Years in Dates”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="descending-indexes.html" title="10.3.13 Descending Indexes">
Section 10.3.13, “Descending Indexes”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-by-optimization.html" title="10.2.1.17 GROUP BY Optimization">
Section 10.2.1.17, “GROUP BY Optimization”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mysql-indexes.html" title="10.3.1 How MySQL Uses Indexes">
Section 10.3.1, “How MySQL Uses Indexes”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="known-issues.html" title="B.3.7 Known Issues in MySQL">
Section B.3.7, “Known Issues in MySQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mysql-cluster-programs-ndb-restore.html" title="25.5.23 ndb_restore — Restore an NDB Cluster Backup">
Section 25.5.23, “ndb_restore — Restore an NDB Cluster Backup”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="numeric-type-syntax.html" title="13.1.1 Numeric Data Type Syntax">
Section 13.1.1, “Numeric Data Type Syntax”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="derived-table-optimization.html" title="10.2.2.4 Optimizing Derived Tables, View References, and Common Table Expressions with Merging or Materialization">
Section 10.2.2.4, “Optimizing Derived Tables, View References, and Common Table Expressions
with Merging or Materialization”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="sql-mode.html" title="7.1.11 Server SQL Modes">
Section 7.1.11, “Server SQL Modes”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="switchable-optimizations.html" title="10.9.2 Switchable Optimizations">
Section 10.9.2, “Switchable Optimizations”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="features.html" title="1.2.2 The Main Features of MySQL">
Section 1.2.2, “The Main Features of MySQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-tp-thread-group-state-table.html" title="29.12.16.2 The tp_thread_group_state Table">
Section 29.12.16.2, “The tp_thread_group_state Table”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="view-updatability.html" title="27.5.3 Updatable and Insertable Views">
Section 27.5.3, “Updatable and Insertable Views”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="index-extensions.html" title="10.3.10 Use of Index Extensions">
Section 10.3.10, “Use of Index Extensions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="example-auto-increment.html" title="5.6.9 Using AUTO_INCREMENT">
Section 5.6.9, “Using AUTO_INCREMENT”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="window-function-optimization.html" title="10.2.1.21 Window Function Optimization">
Section 10.2.1.21, “Window Function Optimization”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="with.html" title="15.2.20 WITH (Common Table Expressions)">
Section 15.2.20, “WITH (Common Table Expressions)”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MBRContains()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-mbr.html" title="14.16.9.2 Spatial Relation Functions That Use Minimum Bounding Rectangles">
Section 14.16.9.2, “Spatial Relation Functions That Use Minimum Bounding Rectangles”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="using-spatial-indexes.html" title="13.4.11 Using Spatial Indexes">
Section 13.4.11, “Using Spatial Indexes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MBRCoveredBy()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-mbr.html" title="14.16.9.2 Spatial Relation Functions That Use Minimum Bounding Rectangles">
Section 14.16.9.2, “Spatial Relation Functions That Use Minimum Bounding Rectangles”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MBRCovers()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-mbr.html" title="14.16.9.2 Spatial Relation Functions That Use Minimum Bounding Rectangles">
Section 14.16.9.2, “Spatial Relation Functions That Use Minimum Bounding Rectangles”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MBRDisjoint()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-mbr.html" title="14.16.9.2 Spatial Relation Functions That Use Minimum Bounding Rectangles">
Section 14.16.9.2, “Spatial Relation Functions That Use Minimum Bounding Rectangles”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MBREquals()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-mbr.html" title="14.16.9.2 Spatial Relation Functions That Use Minimum Bounding Rectangles">
Section 14.16.9.2, “Spatial Relation Functions That Use Minimum Bounding Rectangles”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MBRIntersects()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-mbr.html" title="14.16.9.2 Spatial Relation Functions That Use Minimum Bounding Rectangles">
Section 14.16.9.2, “Spatial Relation Functions That Use Minimum Bounding Rectangles”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MBROverlaps()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-mbr.html" title="14.16.9.2 Spatial Relation Functions That Use Minimum Bounding Rectangles">
Section 14.16.9.2, “Spatial Relation Functions That Use Minimum Bounding Rectangles”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MBRTouches()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-mbr.html" title="14.16.9.2 Spatial Relation Functions That Use Minimum Bounding Rectangles">
Section 14.16.9.2, “Spatial Relation Functions That Use Minimum Bounding Rectangles”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MBRWithin()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-mbr.html" title="14.16.9.2 Spatial Relation Functions That Use Minimum Bounding Rectangles">
Section 14.16.9.2, “Spatial Relation Functions That Use Minimum Bounding Rectangles”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="using-spatial-indexes.html" title="13.4.11 Using Spatial Indexes">
Section 13.4.11, “Using Spatial Indexes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MD5()
</h3>
<dl>
<dt>
<a class="xref" href="encryption-functions.html" title="14.13 Encryption and Compression Functions">
Section 14.13, “Encryption and Compression Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-key.html" title="26.2.5 KEY Partitioning">
Section 26.2.5, “KEY Partitioning”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="identifiers.html" title="11.2 Schema Object Names">
Section 11.2, “Schema Object Names”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MICROSECOND()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MID()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MIN(
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MIN()
</h3>
<dl>
<dt>
<a class="xref" href="two-digit-years.html" title="13.2.9 2-Digit Years in Dates">
Section 13.2.9, “2-Digit Years in Dates”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="descending-indexes.html" title="10.3.13 Descending Indexes">
Section 10.3.13, “Descending Indexes”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-by-optimization.html" title="10.2.1.17 GROUP BY Optimization">
Section 10.2.1.17, “GROUP BY Optimization”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mysql-indexes.html" title="10.3.1 How MySQL Uses Indexes">
Section 10.3.1, “How MySQL Uses Indexes”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="known-issues.html" title="B.3.7 Known Issues in MySQL">
Section B.3.7, “Known Issues in MySQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mysql-cluster-programs-ndb-restore.html" title="25.5.23 ndb_restore — Restore an NDB Cluster Backup">
Section 25.5.23, “ndb_restore — Restore an NDB Cluster Backup”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="numeric-type-syntax.html" title="13.1.1 Numeric Data Type Syntax">
Section 13.1.1, “Numeric Data Type Syntax”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="derived-table-optimization.html" title="10.2.2.4 Optimizing Derived Tables, View References, and Common Table Expressions with Merging or Materialization">
Section 10.2.2.4, “Optimizing Derived Tables, View References, and Common Table Expressions
with Merging or Materialization”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="problems-with-null.html" title="B.3.4.3 Problems with NULL Values">
Section B.3.4.3, “Problems with NULL Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="switchable-optimizations.html" title="10.9.2 Switchable Optimizations">
Section 10.9.2, “Switchable Optimizations”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="features.html" title="1.2.2 The Main Features of MySQL">
Section 1.2.2, “The Main Features of MySQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="view-updatability.html" title="27.5.3 Updatable and Insertable Views">
Section 27.5.3, “Updatable and Insertable Views”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="index-extensions.html" title="10.3.10 Use of Index Extensions">
Section 10.3.10, “Use of Index Extensions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="where-optimization.html" title="10.2.1.1 WHERE Clause Optimization">
Section 10.2.1.1, “WHERE Clause Optimization”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="window-function-optimization.html" title="10.2.1.21 Window Function Optimization">
Section 10.2.1.21, “Window Function Optimization”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MINUTE()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MOD()
</h3>
<dl>
<dt>
<a class="xref" href="arithmetic-functions.html" title="14.6.1 Arithmetic Operators">
Section 14.6.1, “Arithmetic Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-calculations.html" title="5.3.4.5 Date Calculations">
Section 5.3.4.5, “Date Calculations”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="sql-mode.html" title="7.1.11 Server SQL Modes">
Section 7.1.11, “Server SQL Modes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MONTH()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-calculations.html" title="5.3.4.5 Date Calculations">
Section 5.3.4.5, “Date Calculations”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-types.html" title="26.2 Partitioning Types">
Section 26.2, “Partitioning Types”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MONTHNAME()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="locale-support.html" title="12.16 MySQL Server Locale Support">
Section 12.16, “MySQL Server Locale Support”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MultiLineString()
</h3>
<dl>
<dt>
<a class="xref" href="gis-mysql-specific-functions.html" title="14.16.5 MySQL-Specific Functions That Create Geometry Values">
Section 14.16.5, “MySQL-Specific Functions That Create Geometry Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MultiPoint()
</h3>
<dl>
<dt>
<a class="xref" href="gis-mysql-specific-functions.html" title="14.16.5 MySQL-Specific Functions That Create Geometry Values">
Section 14.16.5, “MySQL-Specific Functions That Create Geometry Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
MultiPolygon()
</h3>
<dl>
<dt>
<a class="xref" href="gis-mysql-specific-functions.html" title="14.16.5 MySQL-Specific Functions That Create Geometry Values">
Section 14.16.5, “MySQL-Specific Functions That Create Geometry Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
my_open()
</h3>
<dl>
<dt>
<a class="xref" href="server-status-variables.html" title="7.1.10 Server Status Variables">
Section 7.1.10, “Server Status Variables”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
mysql_firewall_flush_status()
</h3>
<dl>
<dt>
<a class="xref" href="firewall-reference.html" title="8.4.7.4 MySQL Enterprise Firewall Reference">
Section 8.4.7.4, “MySQL Enterprise Firewall Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
mysql_query_attribute_string()
</h3>
<dl>
<dt>
<a class="xref" href="query-attribute-components.html" title="7.5.4 Query Attribute Components">
Section 7.5.4, “Query Attribute Components”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="query-attributes.html" title="11.6 Query Attributes">
Section 11.6, “Query Attributes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-N">
</a>
<h3 class="title">
N
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
NAME_CONST()
</h3>
<dl>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="stored-programs-logging.html" title="27.7 Stored Program Binary Logging">
Section 27.7, “Stored Program Binary Logging”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
normalize_statement()
</h3>
<dl>
<dt>
<a class="xref" href="firewall-reference.html" title="8.4.7.4 MySQL Enterprise Firewall Reference">
Section 8.4.7.4, “MySQL Enterprise Firewall Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
NOW()
</h3>
<dl>
<dt>
<a class="xref" href="replication-sbr-rbr.html" title="19.2.1.1 Advantages and Disadvantages of Statement-Based and Row-Based Replication">
Section 19.2.1.1, “Advantages and Disadvantages of Statement-Based and Row-Based
Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="timestamp-initialization.html" title="13.2.5 Automatic Initialization and Updating for TIMESTAMP and DATETIME">
Section 13.2.5, “Automatic Initialization and Updating for TIMESTAMP and DATETIME”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-table-check-constraints.html" title="15.1.20.6 CHECK Constraints">
Section 15.1.20.6, “CHECK Constraints”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-procedure.html" title="15.1.17 CREATE PROCEDURE and CREATE FUNCTION Statements">
Section 15.1.17, “CREATE PROCEDURE and CREATE FUNCTION Statements”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-table-generated-columns.html" title="15.1.20.8 CREATE TABLE and Generated Columns">
Section 15.1.20.8, “CREATE TABLE and Generated Columns”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="fractional-seconds.html" title="13.2.6 Fractional Seconds in Time Values">
Section 13.2.6, “Fractional Seconds in Time Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="faqs-general.html" title="A.1 MySQL 8.4 FAQ: General">
Section A.1, “MySQL 8.4 FAQ: General”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="time-zone-support.html" title="7.1.15 MySQL Server Time Zone Support">
Section 7.1.15, “MySQL Server Time Zone Support”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-functions.html" title="19.5.1.14 Replication and System Functions">
Section 19.5.1.14, “Replication and System Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-timezone.html" title="19.5.1.33 Replication and Time Zones">
Section 19.5.1.33, “Replication and Time Zones”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-options.html" title="7.1.7 Server Command Options">
Section 7.1.7, “Server Command Options”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="sys-metrics.html" title="30.4.3.21 The metrics View">
Section 30.4.3.21, “The metrics View”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="sys-statement-performance-analyzer.html" title="30.4.4.25 The statement_performance_analyzer() Procedure">
Section 30.4.4.25, “The statement_performance_analyzer() Procedure”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="year.html" title="13.2.4 The YEAR Type">
Section 13.2.4, “The YEAR Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
NTH_VALUE()
</h3>
<dl>
<dt>
<a class="xref" href="window-function-descriptions.html" title="14.20.1 Window Function Descriptions">
Section 14.20.1, “Window Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="window-functions-frames.html" title="14.20.3 Window Function Frame Specification">
Section 14.20.3, “Window Function Frame Specification”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
NTILE()
</h3>
<dl>
<dt>
<a class="xref" href="window-function-descriptions.html" title="14.20.1 Window Function Descriptions">
Section 14.20.1, “Window Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
NULLIF
</h3>
<dl>
<dt>
<a class="xref" href="prepare.html" title="15.5.1 PREPARE Statement">
Section 15.5.1, “PREPARE Statement”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
NULLIF()
</h3>
<dl>
<dt>
<a class="xref" href="flow-control-functions.html" title="14.5 Flow Control Functions">
Section 14.5, “Flow Control Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-O">
</a>
<h3 class="title">
O
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
OCT()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
OCTET_LENGTH()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ORD()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-P">
</a>
<h3 class="title">
P
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
PERCENT_RANK()
</h3>
<dl>
<dt>
<a class="xref" href="window-function-descriptions.html" title="14.20.1 Window Function Descriptions">
Section 14.20.1, “Window Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
PERIOD_ADD()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
PERIOD_DIFF()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
PI()
</h3>
<dl>
<dt>
<a class="xref" href="function-resolution.html" title="11.2.5 Function Name Parsing and Resolution">
Section 11.2.5, “Function Name Parsing and Resolution”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
Point()
</h3>
<dl>
<dt>
<a class="xref" href="gis-mysql-specific-functions.html" title="14.16.5 MySQL-Specific Functions That Create Geometry Values">
Section 14.16.5, “MySQL-Specific Functions That Create Geometry Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="gis-data-formats.html" title="13.4.3 Supported Spatial Data Formats">
Section 13.4.3, “Supported Spatial Data Formats”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
Polygon()
</h3>
<dl>
<dt>
<a class="xref" href="gis-mysql-specific-functions.html" title="14.16.5 MySQL-Specific Functions That Create Geometry Values">
Section 14.16.5, “MySQL-Specific Functions That Create Geometry Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
POSITION()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
POW()
</h3>
<dl>
<dt>
<a class="xref" href="function-optimization.html" title="10.2.1.20 Function Call Optimization">
Section 10.2.1.20, “Function Call Optimization”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-hash.html" title="26.2.4 HASH Partitioning">
Section 26.2.4, “HASH Partitioning”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
POWER()
</h3>
<dl>
<dt>
<a class="xref" href="partitioning-linear-hash.html" title="26.2.4.1 LINEAR HASH Partitioning">
Section 26.2.4.1, “LINEAR HASH Partitioning”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
PS_CURRENT_THREAD_ID()
</h3>
<dl>
<dt>
<a class="xref" href="performance-schema-functions.html" title="14.21 Performance Schema Functions">
Section 14.21, “Performance Schema Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="sys-ps-thread-id.html" title="30.4.5.15 The ps_thread_id() Function">
Section 30.4.5.15, “The ps_thread_id() Function”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
PS_THREAD_ID()
</h3>
<dl>
<dt>
<a class="xref" href="performance-schema-functions.html" title="14.21 Performance Schema Functions">
Section 14.21, “Performance Schema Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="sys-ps-thread-id.html" title="30.4.5.15 The ps_thread_id() Function">
Section 30.4.5.15, “The ps_thread_id() Function”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-Q">
</a>
<h3 class="title">
Q
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
QUARTER()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
QUOTE()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-literals.html" title="11.1.1 String Literals">
Section 11.1.1, “String Literals”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-R">
</a>
<h3 class="title">
R
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
RADIANS()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
RAND()
</h3>
<dl>
<dt>
<a class="xref" href="replication-sbr-rbr.html" title="19.2.1.1 Advantages and Disadvantages of Statement-Based and Row-Based Replication">
Section 19.2.1.1, “Advantages and Disadvantages of Statement-Based and Row-Based
Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-procedure.html" title="15.1.17 CREATE PROCEDURE and CREATE FUNCTION Statements">
Section 15.1.17, “CREATE PROCEDURE and CREATE FUNCTION Statements”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="function-optimization.html" title="10.2.1.20 Function Call Optimization">
Section 10.2.1.20, “Function Call Optimization”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="data-masking-component-functions.html" title="8.5.2.4 MySQL Enterprise Data Masking and De-Identification Component Function Descriptions">
Section 8.5.2.4, “MySQL Enterprise Data Masking and De-Identification Component Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-functions.html" title="19.5.1.14 Replication and System Functions">
Section 19.5.1.14, “Replication and System Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="switchable-optimizations.html" title="10.9.2 Switchable Optimizations">
Section 10.9.2, “Switchable Optimizations”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
RANDOM_BYTES()
</h3>
<dl>
<dt>
<a class="xref" href="encryption-functions.html" title="14.13 Encryption and Compression Functions">
Section 14.13, “Encryption and Compression Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
RANK()
</h3>
<dl>
<dt>
<a class="xref" href="window-function-descriptions.html" title="14.20.1 Window Function Descriptions">
Section 14.20.1, “Window Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
read_firewall_group_allowlist()
</h3>
<dl>
<dt>
<a class="xref" href="firewall-reference.html" title="8.4.7.4 MySQL Enterprise Firewall Reference">
Section 8.4.7.4, “MySQL Enterprise Firewall Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
read_firewall_groups()
</h3>
<dl>
<dt>
<a class="xref" href="firewall-reference.html" title="8.4.7.4 MySQL Enterprise Firewall Reference">
Section 8.4.7.4, “MySQL Enterprise Firewall Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
read_firewall_users()
</h3>
<dl>
<dt>
<a class="xref" href="firewall-reference.html" title="8.4.7.4 MySQL Enterprise Firewall Reference">
Section 8.4.7.4, “MySQL Enterprise Firewall Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
read_firewall_whitelist()
</h3>
<dl>
<dt>
<a class="xref" href="firewall-reference.html" title="8.4.7.4 MySQL Enterprise Firewall Reference">
Section 8.4.7.4, “MySQL Enterprise Firewall Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
REGEXP_INSTR()
</h3>
<dl>
<dt>
<a class="xref" href="regexp.html" title="14.8.2 Regular Expressions">
Section 14.8.2, “Regular Expressions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
REGEXP_LIKE()
</h3>
<dl>
<dt>
<a class="xref" href="pattern-matching.html" title="5.3.4.7 Pattern Matching">
Section 5.3.4.7, “Pattern Matching”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="regexp.html" title="14.8.2 Regular Expressions">
Section 14.8.2, “Regular Expressions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
REGEXP_REPLACE()
</h3>
<dl>
<dt>
<a class="xref" href="regexp.html" title="14.8.2 Regular Expressions">
Section 14.8.2, “Regular Expressions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
REGEXP_SUBSTR()
</h3>
<dl>
<dt>
<a class="xref" href="regexp.html" title="14.8.2 Regular Expressions">
Section 14.8.2, “Regular Expressions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
RELEASE_ALL_LOCKS()
</h3>
<dl>
<dt>
<a class="xref" href="locking-functions.html" title="14.14 Locking Functions">
Section 14.14, “Locking Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
RELEASE_LOCK()
</h3>
<dl>
<dt>
<a class="xref" href="replication-sbr-rbr.html" title="19.2.1.1 Advantages and Disadvantages of Statement-Based and Row-Based Replication">
Section 19.2.1.1, “Advantages and Disadvantages of Statement-Based and Row-Based
Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="do.html" title="15.2.3 DO Statement">
Section 15.2.3, “DO Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="internal-locking.html" title="10.11.1 Internal Locking Methods">
Section 10.11.1, “Internal Locking Methods”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="lock-tables.html" title="15.3.6 LOCK TABLES and UNLOCK TABLES Statements">
Section 15.3.6, “LOCK TABLES and UNLOCK TABLES Statements”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="locking-functions.html" title="14.14 Locking Functions">
Section 14.14, “Locking Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-functions.html" title="19.5.1.14 Replication and System Functions">
Section 19.5.1.14, “Replication and System Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
REPEAT()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
REPLACE()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
REVERSE()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
RIGHT()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ROLES_GRAPHML()
</h3>
<dl>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="privileges-provided.html" title="8.2.2 Privileges Provided by MySQL">
Section 8.2.2, “Privileges Provided by MySQL”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ROUND()
</h3>
<dl>
<dt>
<a class="xref" href="innodb-information-schema-system-tables.html" title="17.15.3 InnoDB INFORMATION_SCHEMA Schema Object Tables">
Section 17.15.3, “InnoDB INFORMATION_SCHEMA Schema Object Tables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="precision-math.html" title="14.24 Precision Math">
Section 14.24, “Precision Math”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="precision-math-examples.html" title="14.24.5 Precision Math Examples">
Section 14.24.5, “Precision Math Examples”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="precision-math-rounding.html" title="14.24.4 Rounding Behavior">
Section 14.24.4, “Rounding Behavior”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ROW_COUNT()
</h3>
<dl>
<dt>
<a class="xref" href="call.html" title="15.2.1 CALL Statement">
Section 15.2.1, “CALL Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="delete.html" title="15.2.2 DELETE Statement">
Section 15.2.2, “DELETE Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="insert.html" title="15.2.7 INSERT Statement">
Section 15.2.7, “INSERT Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="binary-log-mixed.html" title="7.4.4.3 Mixed Binary Logging Format">
Section 7.4.4.3, “Mixed Binary Logging Format”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-functions.html" title="19.5.1.14 Replication and System Functions">
Section 19.5.1.14, “Replication and System Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-status-variables.html" title="7.1.10 Server Status Variables">
Section 7.1.10, “Server Status Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="diagnostics-area.html" title="15.6.7.7 The MySQL Diagnostics Area">
Section 15.6.7.7, “The MySQL Diagnostics Area”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ROW_NUMBER()
</h3>
<dl>
<dt>
<a class="xref" href="window-functions-usage.html" title="14.20.2 Window Function Concepts and Syntax">
Section 14.20.2, “Window Function Concepts and Syntax”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="window-function-descriptions.html" title="14.20.1 Window Function Descriptions">
Section 14.20.1, “Window Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
RPAD()
</h3>
<dl>
<dt>
<a class="xref" href="bit-functions.html" title="14.12 Bit Functions and Operators">
Section 14.12, “Bit Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
RTRIM()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-S">
</a>
<h3 class="title">
S
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SCHEMA()
</h3>
<dl>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SEC_TO_TIME()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SECOND()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
service_get_read_locks()
</h3>
<dl>
<dt>
<a class="xref" href="locking-service.html#locking-service-interface" title="7.6.9.1.2 The Locking Service Function Interface">
Section 7.6.9.1.2, “The Locking Service Function Interface”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
service_get_write_locks()
</h3>
<dl>
<dt>
<a class="xref" href="locking-service.html#locking-service-interface" title="7.6.9.1.2 The Locking Service Function Interface">
Section 7.6.9.1.2, “The Locking Service Function Interface”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
service_release_locks()
</h3>
<dl>
<dt>
<a class="xref" href="locking-service.html#locking-service-interface" title="7.6.9.1.2 The Locking Service Function Interface">
Section 7.6.9.1.2, “The Locking Service Function Interface”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SESSION_USER()
</h3>
<dl>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-metadata.html" title="12.2.2 UTF-8 for Metadata">
Section 12.2.2, “UTF-8 for Metadata”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
set_firewall_group_mode()
</h3>
<dl>
<dt>
<a class="xref" href="firewall-reference.html" title="8.4.7.4 MySQL Enterprise Firewall Reference">
Section 8.4.7.4, “MySQL Enterprise Firewall Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
set_firewall_mode()
</h3>
<dl>
<dt>
<a class="xref" href="firewall-reference.html" title="8.4.7.4 MySQL Enterprise Firewall Reference">
Section 8.4.7.4, “MySQL Enterprise Firewall Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
setrlimit()
</h3>
<dl>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SHA()
</h3>
<dl>
<dt>
<a class="xref" href="encryption-functions.html" title="14.13 Encryption and Compression Functions">
Section 14.13, “Encryption and Compression Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SHA1()
</h3>
<dl>
<dt>
<a class="xref" href="encryption-functions.html" title="14.13 Encryption and Compression Functions">
Section 14.13, “Encryption and Compression Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SHA2()
</h3>
<dl>
<dt>
<a class="xref" href="encryption-functions.html" title="14.13 Encryption and Compression Functions">
Section 14.13, “Encryption and Compression Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="security-guidelines.html" title="8.1.1 Security Guidelines">
Section 8.1.1, “Security Guidelines”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SIGN()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SIN()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SLEEP()
</h3>
<dl>
<dt>
<a class="xref" href="replication-sbr-rbr.html" title="19.2.1.1 Advantages and Disadvantages of Statement-Based and Row-Based Replication">
Section 19.2.1.1, “Advantages and Disadvantages of Statement-Based and Row-Based
Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="general-thread-states.html" title="10.14.3 General Thread States">
Section 10.14.3, “General Thread States”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-tp-thread-group-stats-table.html" title="29.12.16.3 The tp_thread_group_stats Table">
Section 29.12.16.3, “The tp_thread_group_stats Table”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SOUNDEX()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SOURCE_POS_WAIT()
</h3>
<dl>
<dt>
<a class="xref" href="replication-sbr-rbr.html" title="19.2.1.1 Advantages and Disadvantages of Statement-Based and Row-Based Replication">
Section 19.2.1.1, “Advantages and Disadvantages of Statement-Based and Row-Based
Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="binary-log-transaction-compression.html#binary-log-transaction-compression-enabled" title="7.4.4.5.1 Behaviors When Binary Log Transaction Compression is Enabled">
Section 7.4.4.5.1, “Behaviors When Binary Log Transaction Compression is Enabled”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="channels-commands-single-channel.html" title="19.2.2.1 Commands for Operations on a Single Channel">
Section 19.2.2.1, “Commands for Operations on a Single Channel”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="channels-with-prev-replication.html" title="19.2.2.2 Compatibility with Previous Replication Statements">
Section 19.2.2.2, “Compatibility with Previous Replication Statements”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="faqs-replication.html" title="A.14 MySQL 8.4 FAQ: Replication">
Section A.14, “MySQL 8.4 FAQ: Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-functions-synchronization.html" title="14.18.4 Position-Based Synchronization Functions">
Section 14.18.4, “Position-Based Synchronization Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-gtids-assign-anon.html" title="19.1.3.6 Replication From a Source Without GTIDs to a Replica With GTIDs">
Section 19.1.3.6, “Replication From a Source Without GTIDs to a Replica With GTIDs”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SPACE()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SQRT()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Area()
</h3>
<dl>
<dt>
<a class="xref" href="gis-property-functions.html" title="14.16.7 Geometry Property Functions">
Section 14.16.7, “Geometry Property Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="gis-polygon-property-functions.html" title="14.16.7.4 Polygon and MultiPolygon Property Functions">
Section 14.16.7.4, “Polygon and MultiPolygon Property Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_AsBinary()
</h3>
<dl>
<dt>
<a class="xref" href="fetching-spatial-data.html" title="13.4.8 Fetching Spatial Data">
Section 13.4.8, “Fetching Spatial Data”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="gis-format-conversion-functions.html" title="14.16.6 Geometry Format Conversion Functions">
Section 14.16.6, “Geometry Format Conversion Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_AsGeoJSON()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-geojson-functions.html" title="14.16.11 Spatial GeoJSON Functions">
Section 14.16.11, “Spatial GeoJSON Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_AsText()
</h3>
<dl>
<dt>
<a class="xref" href="fetching-spatial-data.html" title="13.4.8 Fetching Spatial Data">
Section 13.4.8, “Fetching Spatial Data”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="gis-format-conversion-functions.html" title="14.16.6 Geometry Format Conversion Functions">
Section 14.16.6, “Geometry Format Conversion Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_AsWKB()
</h3>
<dl>
<dt>
<a class="xref" href="gis-format-conversion-functions.html" title="14.16.6 Geometry Format Conversion Functions">
Section 14.16.6, “Geometry Format Conversion Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_AsWKT()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="gis-format-conversion-functions.html" title="14.16.6 Geometry Format Conversion Functions">
Section 14.16.6, “Geometry Format Conversion Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Buffer()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Buffer_Strategy()
</h3>
<dl>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Centroid()
</h3>
<dl>
<dt>
<a class="xref" href="gis-polygon-property-functions.html" title="14.16.7.4 Polygon and MultiPolygon Property Functions">
Section 14.16.7.4, “Polygon and MultiPolygon Property Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Collect(
</h3>
<dl>
<dt>
<a class="xref" href="spatial-aggregate-functions.html" title="14.16.12 Spatial Aggregate Functions">
Section 14.16.12, “Spatial Aggregate Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Collect()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-aggregate-functions.html" title="14.16.12 Spatial Aggregate Functions">
Section 14.16.12, “Spatial Aggregate Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Contains()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-object-shapes.html" title="14.16.9.1 Spatial Relation Functions That Use Object Shapes">
Section 14.16.9.1, “Spatial Relation Functions That Use Object Shapes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_ConvexHull()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Crosses()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-object-shapes.html" title="14.16.9.1 Spatial Relation Functions That Use Object Shapes">
Section 14.16.9.1, “Spatial Relation Functions That Use Object Shapes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Difference()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Dimension()
</h3>
<dl>
<dt>
<a class="xref" href="gis-general-property-functions.html" title="14.16.7.1 General Geometry Property Functions">
Section 14.16.7.1, “General Geometry Property Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Disjoint()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-object-shapes.html" title="14.16.9.1 Spatial Relation Functions That Use Object Shapes">
Section 14.16.9.1, “Spatial Relation Functions That Use Object Shapes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Distance()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-convenience-functions.html" title="14.16.13 Spatial Convenience Functions">
Section 14.16.13, “Spatial Convenience Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="spatial-relation-functions-object-shapes.html" title="14.16.9.1 Spatial Relation Functions That Use Object Shapes">
Section 14.16.9.1, “Spatial Relation Functions That Use Object Shapes”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-schema-st-units-of-measure-table.html" title="28.3.37 The INFORMATION_SCHEMA ST_UNITS_OF_MEASURE Table">
Section 28.3.37, “The INFORMATION_SCHEMA ST_UNITS_OF_MEASURE Table”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Distance_Sphere()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-convenience-functions.html" title="14.16.13 Spatial Convenience Functions">
Section 14.16.13, “Spatial Convenience Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="spatial-relation-functions-object-shapes.html" title="14.16.9.1 Spatial Relation Functions That Use Object Shapes">
Section 14.16.9.1, “Spatial Relation Functions That Use Object Shapes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_EndPoint()
</h3>
<dl>
<dt>
<a class="xref" href="gis-linestring-property-functions.html" title="14.16.7.3 LineString and MultiLineString Property Functions">
Section 14.16.7.3, “LineString and MultiLineString Property Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Envelope()
</h3>
<dl>
<dt>
<a class="xref" href="gis-general-property-functions.html" title="14.16.7.1 General Geometry Property Functions">
Section 14.16.7.1, “General Geometry Property Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Equals()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-object-shapes.html" title="14.16.9.1 Spatial Relation Functions That Use Object Shapes">
Section 14.16.9.1, “Spatial Relation Functions That Use Object Shapes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_ExteriorRing()
</h3>
<dl>
<dt>
<a class="xref" href="gis-polygon-property-functions.html" title="14.16.7.4 Polygon and MultiPolygon Property Functions">
Section 14.16.7.4, “Polygon and MultiPolygon Property Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_FrechetDistance()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-object-shapes.html" title="14.16.9.1 Spatial Relation Functions That Use Object Shapes">
Section 14.16.9.1, “Spatial Relation Functions That Use Object Shapes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_GeoHash()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-geohash-functions.html" title="14.16.10 Spatial Geohash Functions">
Section 14.16.10, “Spatial Geohash Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_GeomCollFromText()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_GeomCollFromTxt()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_GeomCollFromWKB()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkb-functions.html" title="14.16.4 Functions That Create Geometry Values from WKB Values">
Section 14.16.4, “Functions That Create Geometry Values from WKB Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_GeometryCollectionFromText()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_GeometryCollectionFromWKB()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkb-functions.html" title="14.16.4 Functions That Create Geometry Values from WKB Values">
Section 14.16.4, “Functions That Create Geometry Values from WKB Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_GeometryFromText()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_GeometryFromWKB()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkb-functions.html" title="14.16.4 Functions That Create Geometry Values from WKB Values">
Section 14.16.4, “Functions That Create Geometry Values from WKB Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_GeometryN()
</h3>
<dl>
<dt>
<a class="xref" href="gis-geometrycollection-property-functions.html" title="14.16.7.5 GeometryCollection Property Functions">
Section 14.16.7.5, “GeometryCollection Property Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_GeometryType()
</h3>
<dl>
<dt>
<a class="xref" href="gis-general-property-functions.html" title="14.16.7.1 General Geometry Property Functions">
Section 14.16.7.1, “General Geometry Property Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_GeomFromGeoJSON()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-geojson-functions.html" title="14.16.11 Spatial GeoJSON Functions">
Section 14.16.11, “Spatial GeoJSON Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="json.html" title="13.5 The JSON Data Type">
Section 13.5, “The JSON Data Type”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_GeomFromText()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="gis-format-conversion-functions.html" title="14.16.6 Geometry Format Conversion Functions">
Section 14.16.6, “Geometry Format Conversion Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="gis-mysql-specific-functions.html" title="14.16.5 MySQL-Specific Functions That Create Geometry Values">
Section 14.16.5, “MySQL-Specific Functions That Create Geometry Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="populating-spatial-columns.html" title="13.4.7 Populating Spatial Columns">
Section 13.4.7, “Populating Spatial Columns”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="gis-data-formats.html" title="13.4.3 Supported Spatial Data Formats">
Section 13.4.3, “Supported Spatial Data Formats”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_GeomFromWKB()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkb-functions.html" title="14.16.4 Functions That Create Geometry Values from WKB Values">
Section 14.16.4, “Functions That Create Geometry Values from WKB Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_HausdorffDistance()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-object-shapes.html" title="14.16.9.1 Spatial Relation Functions That Use Object Shapes">
Section 14.16.9.1, “Spatial Relation Functions That Use Object Shapes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_InteriorRingN()
</h3>
<dl>
<dt>
<a class="xref" href="gis-polygon-property-functions.html" title="14.16.7.4 Polygon and MultiPolygon Property Functions">
Section 14.16.7.4, “Polygon and MultiPolygon Property Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Intersection()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Intersects()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-object-shapes.html" title="14.16.9.1 Spatial Relation Functions That Use Object Shapes">
Section 14.16.9.1, “Spatial Relation Functions That Use Object Shapes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_IsClosed()
</h3>
<dl>
<dt>
<a class="xref" href="gis-linestring-property-functions.html" title="14.16.7.3 LineString and MultiLineString Property Functions">
Section 14.16.7.3, “LineString and MultiLineString Property Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_IsEmpty()
</h3>
<dl>
<dt>
<a class="xref" href="gis-general-property-functions.html" title="14.16.7.1 General Geometry Property Functions">
Section 14.16.7.1, “General Geometry Property Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_IsSimple()
</h3>
<dl>
<dt>
<a class="xref" href="gis-general-property-functions.html" title="14.16.7.1 General Geometry Property Functions">
Section 14.16.7.1, “General Geometry Property Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_IsValid()
</h3>
<dl>
<dt>
<a class="xref" href="geometry-well-formedness-validity.html" title="13.4.4 Geometry Well-Formedness and Validity">
Section 13.4.4, “Geometry Well-Formedness and Validity”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="spatial-convenience-functions.html" title="14.16.13 Spatial Convenience Functions">
Section 14.16.13, “Spatial Convenience Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_LatFromGeoHash()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-geohash-functions.html" title="14.16.10 Spatial Geohash Functions">
Section 14.16.10, “Spatial Geohash Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Latitude()
</h3>
<dl>
<dt>
<a class="xref" href="gis-point-property-functions.html" title="14.16.7.2 Point Property Functions">
Section 14.16.7.2, “Point Property Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Length()
</h3>
<dl>
<dt>
<a class="xref" href="gis-linestring-property-functions.html" title="14.16.7.3 LineString and MultiLineString Property Functions">
Section 14.16.7.3, “LineString and MultiLineString Property Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_LineFromText()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_LineFromWKB()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkb-functions.html" title="14.16.4 Functions That Create Geometry Values from WKB Values">
Section 14.16.4, “Functions That Create Geometry Values from WKB Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_LineInterpolatePoint()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_LineInterpolatePoints()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_LineStringFromText()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_LineStringFromWKB()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkb-functions.html" title="14.16.4 Functions That Create Geometry Values from WKB Values">
Section 14.16.4, “Functions That Create Geometry Values from WKB Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_LongFromGeoHash()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-geohash-functions.html" title="14.16.10 Spatial Geohash Functions">
Section 14.16.10, “Spatial Geohash Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Longitude()
</h3>
<dl>
<dt>
<a class="xref" href="gis-point-property-functions.html" title="14.16.7.2 Point Property Functions">
Section 14.16.7.2, “Point Property Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_MakeEnvelope()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-convenience-functions.html" title="14.16.13 Spatial Convenience Functions">
Section 14.16.13, “Spatial Convenience Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_MLineFromText()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_MLineFromWKB()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkb-functions.html" title="14.16.4 Functions That Create Geometry Values from WKB Values">
Section 14.16.4, “Functions That Create Geometry Values from WKB Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_MPointFromText()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="gis-data-formats.html" title="13.4.3 Supported Spatial Data Formats">
Section 13.4.3, “Supported Spatial Data Formats”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_MPointFromWKB()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkb-functions.html" title="14.16.4 Functions That Create Geometry Values from WKB Values">
Section 14.16.4, “Functions That Create Geometry Values from WKB Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_MPolyFromText()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_MPolyFromWKB()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkb-functions.html" title="14.16.4 Functions That Create Geometry Values from WKB Values">
Section 14.16.4, “Functions That Create Geometry Values from WKB Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_MultiLineStringFromText()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_MultiLineStringFromWKB()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkb-functions.html" title="14.16.4 Functions That Create Geometry Values from WKB Values">
Section 14.16.4, “Functions That Create Geometry Values from WKB Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_MultiPointFromText()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_MultiPointFromWKB()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkb-functions.html" title="14.16.4 Functions That Create Geometry Values from WKB Values">
Section 14.16.4, “Functions That Create Geometry Values from WKB Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_MultiPolygonFromText()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_MultiPolygonFromWKB()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkb-functions.html" title="14.16.4 Functions That Create Geometry Values from WKB Values">
Section 14.16.4, “Functions That Create Geometry Values from WKB Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_NumGeometries()
</h3>
<dl>
<dt>
<a class="xref" href="gis-geometrycollection-property-functions.html" title="14.16.7.5 GeometryCollection Property Functions">
Section 14.16.7.5, “GeometryCollection Property Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_NumInteriorRing()
</h3>
<dl>
<dt>
<a class="xref" href="gis-polygon-property-functions.html" title="14.16.7.4 Polygon and MultiPolygon Property Functions">
Section 14.16.7.4, “Polygon and MultiPolygon Property Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_NumInteriorRings()
</h3>
<dl>
<dt>
<a class="xref" href="gis-polygon-property-functions.html" title="14.16.7.4 Polygon and MultiPolygon Property Functions">
Section 14.16.7.4, “Polygon and MultiPolygon Property Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_NuminteriorRings()
</h3>
<dl>
<dt>
<a class="xref" href="gis-polygon-property-functions.html" title="14.16.7.4 Polygon and MultiPolygon Property Functions">
Section 14.16.7.4, “Polygon and MultiPolygon Property Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_NumPoints()
</h3>
<dl>
<dt>
<a class="xref" href="gis-linestring-property-functions.html" title="14.16.7.3 LineString and MultiLineString Property Functions">
Section 14.16.7.3, “LineString and MultiLineString Property Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Overlaps()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-object-shapes.html" title="14.16.9.1 Spatial Relation Functions That Use Object Shapes">
Section 14.16.9.1, “Spatial Relation Functions That Use Object Shapes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_PointAtDistance()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_PointFromGeoHash()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-geohash-functions.html" title="14.16.10 Spatial Geohash Functions">
Section 14.16.10, “Spatial Geohash Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_PointFromText()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_PointFromWKB()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkb-functions.html" title="14.16.4 Functions That Create Geometry Values from WKB Values">
Section 14.16.4, “Functions That Create Geometry Values from WKB Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_PointN()
</h3>
<dl>
<dt>
<a class="xref" href="gis-linestring-property-functions.html" title="14.16.7.3 LineString and MultiLineString Property Functions">
Section 14.16.7.3, “LineString and MultiLineString Property Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_PolyFromText()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_PolyFromWKB()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkb-functions.html" title="14.16.4 Functions That Create Geometry Values from WKB Values">
Section 14.16.4, “Functions That Create Geometry Values from WKB Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_PolygonFromText()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkt-functions.html" title="14.16.3 Functions That Create Geometry Values from WKT Values">
Section 14.16.3, “Functions That Create Geometry Values from WKT Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_PolygonFromWKB()
</h3>
<dl>
<dt>
<a class="xref" href="gis-wkb-functions.html" title="14.16.4 Functions That Create Geometry Values from WKB Values">
Section 14.16.4, “Functions That Create Geometry Values from WKB Values”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Simplify()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-convenience-functions.html" title="14.16.13 Spatial Convenience Functions">
Section 14.16.13, “Spatial Convenience Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_SRID()
</h3>
<dl>
<dt>
<a class="xref" href="gis-general-property-functions.html" title="14.16.7.1 General Geometry Property Functions">
Section 14.16.7.1, “General Geometry Property Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_StartPoint()
</h3>
<dl>
<dt>
<a class="xref" href="gis-linestring-property-functions.html" title="14.16.7.3 LineString and MultiLineString Property Functions">
Section 14.16.7.3, “LineString and MultiLineString Property Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_SwapXY()
</h3>
<dl>
<dt>
<a class="xref" href="gis-format-conversion-functions.html" title="14.16.6 Geometry Format Conversion Functions">
Section 14.16.6, “Geometry Format Conversion Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_SymDifference()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Touches()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-object-shapes.html" title="14.16.9.1 Spatial Relation Functions That Use Object Shapes">
Section 14.16.9.1, “Spatial Relation Functions That Use Object Shapes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Transform()
</h3>
<dl>
<dt>
<a class="xref" href="gis-general-property-functions.html" title="14.16.7.1 General Geometry Property Functions">
Section 14.16.7.1, “General Geometry Property Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Union()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-operator-functions.html" title="14.16.8 Spatial Operator Functions">
Section 14.16.8, “Spatial Operator Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Validate()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-convenience-functions.html" title="14.16.13 Spatial Convenience Functions">
Section 14.16.13, “Spatial Convenience Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Within()
</h3>
<dl>
<dt>
<a class="xref" href="spatial-relation-functions-object-shapes.html" title="14.16.9.1 Spatial Relation Functions That Use Object Shapes">
Section 14.16.9.1, “Spatial Relation Functions That Use Object Shapes”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_X()
</h3>
<dl>
<dt>
<a class="xref" href="gis-point-property-functions.html" title="14.16.7.2 Point Property Functions">
Section 14.16.7.2, “Point Property Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="gis-data-formats.html" title="13.4.3 Supported Spatial Data Formats">
Section 13.4.3, “Supported Spatial Data Formats”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
ST_Y()
</h3>
<dl>
<dt>
<a class="xref" href="gis-point-property-functions.html" title="14.16.7.2 Point Property Functions">
Section 14.16.7.2, “Point Property Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
STATEMENT_DIGEST()
</h3>
<dl>
<dt>
<a class="xref" href="encryption-functions.html" title="14.13 Encryption and Compression Functions">
Section 14.13, “Encryption and Compression Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-statement-digests.html" title="29.10 Performance Schema Statement Digests and Sampling">
Section 29.10, “Performance Schema Statement Digests and Sampling”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
STATEMENT_DIGEST_TEXT()
</h3>
<dl>
<dt>
<a class="xref" href="encryption-functions.html" title="14.13 Encryption and Compression Functions">
Section 14.13, “Encryption and Compression Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="firewall-reference.html" title="8.4.7.4 MySQL Enterprise Firewall Reference">
Section 8.4.7.4, “MySQL Enterprise Firewall Reference”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="performance-schema-statement-digests.html" title="29.10 Performance Schema Statement Digests and Sampling">
Section 29.10, “Performance Schema Statement Digests and Sampling”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
STD()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="features.html" title="1.2.2 The Main Features of MySQL">
Section 1.2.2, “The Main Features of MySQL”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
STDDEV()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
STDDEV_POP()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="window-function-optimization.html" title="10.2.1.21 Window Function Optimization">
Section 10.2.1.21, “Window Function Optimization”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
STDDEV_SAMP()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="window-function-optimization.html" title="10.2.1.21 Window Function Optimization">
Section 10.2.1.21, “Window Function Optimization”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
STR_TO_DATE()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-types.html" title="13.2 Date and Time Data Types">
Section 13.2, “Date and Time Data Types”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="locale-support.html" title="12.16 MySQL Server Locale Support">
Section 12.16, “MySQL Server Locale Support”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
STRCMP()
</h3>
<dl>
<dt>
<a class="xref" href="using-date.html" title="B.3.4.2 Problems Using DATE Columns">
Section B.3.4.2, “Problems Using DATE Columns”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-comparison-functions.html" title="14.8.1 String Comparison Functions and Operators">
Section 14.8.1, “String Comparison Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SUBDATE()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SUBSTR()
</h3>
<dl>
<dt>
<a class="xref" href="bit-functions.html" title="14.12 Bit Functions and Operators">
Section 14.12, “Bit Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SUBSTRING()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-index.html" title="15.1.15 CREATE INDEX Statement">
Section 15.1.15, “CREATE INDEX Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SUBSTRING_INDEX()
</h3>
<dl>
<dt>
<a class="xref" href="account-activity-auditing.html" title="8.2.23 SQL-Based Account Activity Auditing">
Section 8.2.23, “SQL-Based Account Activity Auditing”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SUBTIME()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SUM(
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SUM()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="create-function-loadable.html" title="15.7.4.1 CREATE FUNCTION Statement for Loadable Functions">
Section 15.7.4.1, “CREATE FUNCTION Statement for Loadable Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-type-syntax.html" title="13.2.1 Date and Time Data Type Syntax">
Section 13.2.1, “Date and Time Data Type Syntax”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="group-by-optimization.html" title="10.2.1.17 GROUP BY Optimization">
Section 10.2.1.17, “GROUP BY Optimization”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="derived-table-optimization.html" title="10.2.2.4 Optimizing Derived Tables, View References, and Common Table Expressions with Merging or Materialization">
Section 10.2.2.4, “Optimizing Derived Tables, View References, and Common Table Expressions
with Merging or Materialization”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="problems-with-null.html" title="B.3.4.3 Problems with NULL Values">
Section B.3.4.3, “Problems with NULL Values”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="enum.html" title="13.3.5 The ENUM Type">
Section 13.3.5, “The ENUM Type”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="features.html" title="1.2.2 The Main Features of MySQL">
Section 1.2.2, “The Main Features of MySQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="set.html" title="13.3.6 The SET Type">
Section 13.3.6, “The SET Type”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="view-updatability.html" title="27.5.3 Updatable and Insertable Views">
Section 27.5.3, “Updatable and Insertable Views”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="window-functions-usage.html" title="14.20.2 Window Function Concepts and Syntax">
Section 14.20.2, “Window Function Concepts and Syntax”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="window-functions-frames.html" title="14.20.3 Window Function Frame Specification">
Section 14.20.3, “Window Function Frame Specification”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SYSDATE()
</h3>
<dl>
<dt>
<a class="xref" href="replication-sbr-rbr.html" title="19.2.1.1 Advantages and Disadvantages of Statement-Based and Row-Based Replication">
Section 19.2.1.1, “Advantages and Disadvantages of Statement-Based and Row-Based
Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-functions.html" title="19.5.1.14 Replication and System Functions">
Section 19.5.1.14, “Replication and System Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-options.html" title="7.1.7 Server Command Options">
Section 7.1.7, “Server Command Options”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
SYSTEM_USER()
</h3>
<dl>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-metadata.html" title="12.2.2 UTF-8 for Metadata">
Section 12.2.2, “UTF-8 for Metadata”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-T">
</a>
<h3 class="title">
T
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
TAN()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
TIME()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
TIME_FORMAT()
</h3>
<dl>
<dt>
<a class="xref" href="cast-functions.html" title="14.10 Cast Functions and Operators">
Section 14.10, “Cast Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
TIME_TO_SEC()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
TIMEDIFF()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
TIMESTAMP()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
TIMESTAMPADD()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
TIMESTAMPDIFF()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-calculations.html" title="5.3.4.5 Date Calculations">
Section 5.3.4.5, “Date Calculations”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
TO_BASE64()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
TO_DAYS()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-hash.html" title="26.2.4 HASH Partitioning">
Section 26.2.4, “HASH Partitioning”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-pruning.html" title="26.4 Partition Pruning">
Section 26.4, “Partition Pruning”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-types.html" title="26.2 Partitioning Types">
Section 26.2, “Partitioning Types”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
TO_SECONDS()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-pruning.html" title="26.4 Partition Pruning">
Section 26.4, “Partition Pruning”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-types.html" title="26.2 Partitioning Types">
Section 26.2, “Partitioning Types”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
TRIM()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-conversion.html" title="12.7 Column Character Set Conversion">
Section 12.7, “Column Character Set Conversion”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
TRUNCATE()
</h3>
<dl>
<dt>
<a class="xref" href="mathematical-functions.html" title="14.6.2 Mathematical Functions">
Section 14.6.2, “Mathematical Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-U">
</a>
<h3 class="title">
U
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
UCASE()
</h3>
<dl>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
UNCOMPRESS()
</h3>
<dl>
<dt>
<a class="xref" href="encryption-functions.html" title="14.13 Encryption and Compression Functions">
Section 14.13, “Encryption and Compression Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="source-configuration-options.html" title="2.8.7 MySQL Source-Configuration Options">
Section 2.8.7, “MySQL Source-Configuration Options”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
UNCOMPRESSED_LENGTH()
</h3>
<dl>
<dt>
<a class="xref" href="encryption-functions.html" title="14.13 Encryption and Compression Functions">
Section 14.13, “Encryption and Compression Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
UNHEX()
</h3>
<dl>
<dt>
<a class="xref" href="encryption-functions.html" title="14.13 Encryption and Compression Functions">
Section 14.13, “Encryption and Compression Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mysql-command-options.html" title="6.5.1.1 mysql Client Options">
Section 6.5.1.1, “mysql Client Options”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
UNIX_TIMESTAMP()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="timestamp-lookups.html" title="10.3.14 Indexed Lookups from TIMESTAMP Columns">
Section 10.3.14, “Indexed Lookups from TIMESTAMP Columns”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-range.html" title="26.2.1 RANGE Partitioning">
Section 26.2.1, “RANGE Partitioning”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="sys-metrics.html" title="30.4.3.21 The metrics View">
Section 30.4.3.21, “The metrics View”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="timezone-problems.html" title="B.3.3.7 Time Zone Problems">
Section B.3.3.7, “Time Zone Problems”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
UpdateXML()
</h3>
<dl>
<dt>
<a class="xref" href="xml-functions.html" title="14.11 XML Functions">
Section 14.11, “XML Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
UPPER()
</h3>
<dl>
<dt>
<a class="xref" href="cast-functions.html" title="14.10 Cast Functions and Operators">
Section 14.10, “Cast Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions-charset.html" title="14.8.3 Character Set and Collation of Function Results">
Section 14.8.3, “Character Set and Collation of Function Results”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-repertoire.html" title="12.2.1 Character Set Repertoire">
Section 12.2.1, “Character Set Repertoire”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-unicode-sets.html" title="12.10.1 Unicode Character Sets">
Section 12.10.1, “Unicode Character Sets”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-collation-information-schema.html" title="12.8.7 Using Collation in INFORMATION_SCHEMA Searches">
Section 12.8.7, “Using Collation in INFORMATION_SCHEMA Searches”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
USER()
</h3>
<dl>
<dt>
<a class="xref" href="replication-sbr-rbr.html" title="19.2.1.1 Advantages and Disadvantages of Statement-Based and Row-Based Replication">
Section 19.2.1.1, “Advantages and Disadvantages of Statement-Based and Row-Based
Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="alter-user.html" title="15.7.1.1 ALTER USER Statement">
Section 15.7.1.1, “ALTER USER Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-collation-coercibility.html" title="12.8.4 Collation Coercibility in Expressions">
Section 12.8.4, “Collation Coercibility in Expressions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="ldap-pluggable-authentication.html" title="8.4.1.7 LDAP Pluggable Authentication">
Section 8.4.1.7, “LDAP Pluggable Authentication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="binary-log-mixed.html" title="7.4.4.3 Mixed Binary Logging Format">
Section 7.4.4.3, “Mixed Binary Logging Format”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="network-namespace-support.html" title="7.1.14 Network Namespace Support">
Section 7.1.14, “Network Namespace Support”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="password-management.html" title="8.2.15 Password Management">
Section 8.2.15, “Password Management”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="validate-password-options-variables.html" title="8.4.3.2 Password Validation Options and Variables">
Section 8.4.3.2, “Password Validation Options and Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="proxy-users.html" title="8.2.19 Proxy Users">
Section 8.2.19, “Proxy Users”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-functions.html" title="19.5.1.14 Replication and System Functions">
Section 19.5.1.14, “Replication and System Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="account-activity-auditing.html" title="8.2.23 SQL-Based Account Activity Auditing">
Section 8.2.23, “SQL-Based Account Activity Auditing”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-metadata.html" title="12.2.2 UTF-8 for Metadata">
Section 12.2.2, “UTF-8 for Metadata”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
UTC_DATE
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
UTC_DATE()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
UTC_TIME
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
UTC_TIME()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
UTC_TIMESTAMP
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
UTC_TIMESTAMP()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="time-zone-support.html" title="7.1.15 MySQL Server Time Zone Support">
Section 7.1.15, “MySQL Server Time Zone Support”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
UUID()
</h3>
<dl>
<dt>
<a class="xref" href="replication-sbr-rbr.html" title="19.2.1.1 Advantages and Disadvantages of Statement-Based and Row-Based Replication">
Section 19.2.1.1, “Advantages and Disadvantages of Statement-Based and Row-Based
Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-options-binary-log.html" title="19.1.6.4 Binary Logging Options and Variables">
Section 19.1.6.4, “Binary Logging Options and Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="function-optimization.html" title="10.2.1.20 Function Call Optimization">
Section 10.2.1.20, “Function Call Optimization”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="binary-log-mixed.html" title="7.4.4.3 Mixed Binary Logging Format">
Section 7.4.4.3, “Mixed Binary Logging Format”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-functions.html" title="19.5.1.14 Replication and System Functions">
Section 19.5.1.14, “Replication and System Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="stored-programs-logging.html" title="27.7 Stored Program Binary Logging">
Section 27.7, “Stored Program Binary Logging”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
UUID_SHORT()
</h3>
<dl>
<dt>
<a class="xref" href="replication-sbr-rbr.html" title="19.2.1.1 Advantages and Disadvantages of Statement-Based and Row-Based Replication">
Section 19.2.1.1, “Advantages and Disadvantages of Statement-Based and Row-Based
Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-rbr-safe-unsafe.html" title="19.2.1.3 Determination of Safe and Unsafe Statements in Binary Logging">
Section 19.2.1.3, “Determination of Safe and Unsafe Statements in Binary Logging”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
UUID_TO_BIN()
</h3>
<dl>
<dt>
<a class="xref" href="bit-functions.html" title="14.12 Bit Functions and Operators">
Section 14.12, “Bit Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-V">
</a>
<h3 class="title">
V
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
VALIDATE_PASSWORD_STRENGTH()
</h3>
<dl>
<dt>
<a class="xref" href="encryption-functions.html" title="14.13 Encryption and Compression Functions">
Section 14.13, “Encryption and Compression Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="validate-password-options-variables.html" title="8.4.3.2 Password Validation Options and Variables">
Section 8.4.3.2, “Password Validation Options and Variables”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="validate-password.html" title="8.4.3 The Password Validation Component">
Section 8.4.3, “The Password Validation Component”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
VALUES()
</h3>
<dl>
<dt>
<a class="xref" href="insert-on-duplicate.html" title="15.2.7.2 INSERT ... ON DUPLICATE KEY UPDATE Statement">
Section 15.2.7.2, “INSERT ... ON DUPLICATE KEY UPDATE Statement”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="miscellaneous-functions.html" title="14.23 Miscellaneous Functions">
Section 14.23, “Miscellaneous Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="values.html" title="15.2.19 VALUES Statement">
Section 15.2.19, “VALUES Statement”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
VAR_POP()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="window-function-optimization.html" title="10.2.1.21 Window Function Optimization">
Section 10.2.1.21, “Window Function Optimization”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
VAR_SAMP()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="window-function-optimization.html" title="10.2.1.21 Window Function Optimization">
Section 10.2.1.21, “Window Function Optimization”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
VARIANCE()
</h3>
<dl>
<dt>
<a class="xref" href="aggregate-functions.html" title="14.19.1 Aggregate Function Descriptions">
Section 14.19.1, “Aggregate Function Descriptions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
VERSION()
</h3>
<dl>
<dt>
<a class="xref" href="replication-sbr-rbr.html" title="19.2.1.1 Advantages and Disadvantages of Statement-Based and Row-Based Replication">
Section 19.2.1.1, “Advantages and Disadvantages of Statement-Based and Row-Based
Replication”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="audit-log-file-formats.html" title="8.4.5.4 Audit Log File Formats">
Section 8.4.5.4, “Audit Log File Formats”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="case-sensitivity.html" title="B.3.4.1 Case Sensitivity in String Searches">
Section B.3.4.1, “Case Sensitivity in String Searches”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-collation-coercibility.html" title="12.8.4 Collation Coercibility in Expressions">
Section 12.8.4, “Collation Coercibility in Expressions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-features-functions.html" title="19.5.1.14 Replication and System Functions">
Section 19.5.1.14, “Replication and System Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="sys-version.html" title="30.4.3.47 The version View">
Section 30.4.3.47, “The version View”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-metadata.html" title="12.2.2 UTF-8 for Metadata">
Section 12.2.2, “UTF-8 for Metadata”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
version_tokens_delete()
</h3>
<dl>
<dt>
<a class="xref" href="version-tokens-usage.html" title="7.6.6.3 Using Version Tokens">
Section 7.6.6.3, “Using Version Tokens”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="version-tokens-reference.html" title="7.6.6.4 Version Tokens Reference">
Section 7.6.6.4, “Version Tokens Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
version_tokens_edit()
</h3>
<dl>
<dt>
<a class="xref" href="version-tokens-usage.html" title="7.6.6.3 Using Version Tokens">
Section 7.6.6.3, “Using Version Tokens”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="version-tokens-reference.html" title="7.6.6.4 Version Tokens Reference">
Section 7.6.6.4, “Version Tokens Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
version_tokens_lock_exclusive()
</h3>
<dl>
<dt>
<a class="xref" href="version-tokens-usage.html" title="7.6.6.3 Using Version Tokens">
Section 7.6.6.3, “Using Version Tokens”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="version-tokens-reference.html" title="7.6.6.4 Version Tokens Reference">
Section 7.6.6.4, “Version Tokens Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
version_tokens_lock_shared()
</h3>
<dl>
<dt>
<a class="xref" href="version-tokens-usage.html" title="7.6.6.3 Using Version Tokens">
Section 7.6.6.3, “Using Version Tokens”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="version-tokens-reference.html" title="7.6.6.4 Version Tokens Reference">
Section 7.6.6.4, “Version Tokens Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
version_tokens_set()
</h3>
<dl>
<dt>
<a class="xref" href="version-tokens-usage.html" title="7.6.6.3 Using Version Tokens">
Section 7.6.6.3, “Using Version Tokens”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="version-tokens-reference.html" title="7.6.6.4 Version Tokens Reference">
Section 7.6.6.4, “Version Tokens Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
version_tokens_show()
</h3>
<dl>
<dt>
<a class="xref" href="version-tokens-usage.html" title="7.6.6.3 Using Version Tokens">
Section 7.6.6.3, “Using Version Tokens”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="version-tokens-reference.html" title="7.6.6.4 Version Tokens Reference">
Section 7.6.6.4, “Version Tokens Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
version_tokens_unlock()
</h3>
<dl>
<dt>
<a class="xref" href="version-tokens-usage.html" title="7.6.6.3 Using Version Tokens">
Section 7.6.6.3, “Using Version Tokens”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="version-tokens-reference.html" title="7.6.6.4 Version Tokens Reference">
Section 7.6.6.4, “Version Tokens Reference”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-W">
</a>
<h3 class="title">
W
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
WAIT_FOR_EXECUTED_GTID_SET()
</h3>
<dl>
<dt>
<a class="xref" href="gtid-functions.html" title="14.18.2 Functions Used with Global Transaction Identifiers (GTIDs)">
Section 14.18.2, “Functions Used with Global Transaction Identifiers (GTIDs)”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-gtids-assign-anon.html" title="19.1.3.6 Replication From a Source Without GTIDs to a Replica With GTIDs">
Section 19.1.3.6, “Replication From a Source Without GTIDs to a Replica With GTIDs”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="replication-mode-change-online-concepts.html" title="19.1.4.1 Replication Mode Concepts">
Section 19.1.4.1, “Replication Mode Concepts”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="mysql-nutshell.html" title="1.4 What Is New in MySQL 8.4 since MySQL 8.0">
Section 1.4, “What Is New in MySQL 8.4 since MySQL 8.0”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
WEEK()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="server-system-variables.html" title="7.1.8 Server System Variables">
Section 7.1.8, “Server System Variables”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
WEEKDAY()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="extensions-to-ansi.html" title="1.7.1 MySQL Extensions to Standard SQL">
Section 1.7.1, “MySQL Extensions to Standard SQL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-types.html" title="26.2 Partitioning Types">
Section 26.2, “Partitioning Types”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
WEEKOFYEAR()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
WEIGHT_STRING()
</h3>
<dl>
<dt>
<a class="xref" href="adding-collation.html" title="12.14 Adding a Collation to a Character Set">
Section 12.14, “Adding a Collation to a Character Set”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="case-sensitivity.html" title="B.3.4.1 Case Sensitivity in String Searches">
Section B.3.4.1, “Case Sensitivity in String Searches”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="string-functions.html" title="14.8 String Functions and Operators">
Section 14.8, “String Functions and Operators”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="charset-unicode-sets.html" title="12.10.1 Unicode Character Sets">
Section 12.10.1, “Unicode Character Sets”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<a name="func-index-Y">
</a>
<h3 class="title">
Y
</h3>
<p>
[
<a class="link" href="dynindex-function.html#func-index-top">
index top
</a>
]
</p>
<dl>
<dt>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
YEAR()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="date-calculations.html" title="5.3.4.5 Date Calculations">
Section 5.3.4.5, “Date Calculations”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-hash.html" title="26.2.4 HASH Partitioning">
Section 26.2.4, “HASH Partitioning”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-handling-nulls.html" title="26.2.7 How MySQL Partitioning Handles NULL">
Section 26.2.7, “How MySQL Partitioning Handles NULL”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-management-range-list.html" title="26.3.1 Management of RANGE and LIST Partitions">
Section 26.3.1, “Management of RANGE and LIST Partitions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-pruning.html" title="26.4 Partition Pruning">
Section 26.4, “Partition Pruning”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-types.html" title="26.2 Partitioning Types">
Section 26.2, “Partitioning Types”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-range.html" title="26.2.1 RANGE Partitioning">
Section 26.2.1, “RANGE Partitioning”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
<div class="indexdiv">
<h3 class="title">
YEARWEEK()
</h3>
<dl>
<dt>
<a class="xref" href="date-and-time-functions.html" title="14.7 Date and Time Functions">
Section 14.7, “Date and Time Functions”
</a>
</dt>
<dd>
</dd>
<dt>
<a class="xref" href="partitioning-limitations-functions.html" title="26.6.3 Partitioning Limitations Relating to Functions">
Section 26.6.3, “Partitioning Limitations Relating to Functions”
</a>
</dt>
<dd>
</dd>
</dl>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-ndbinfo-pgman-time-track-stats.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="mysql-cluster-ndbinfo-pgman-time-track-stats">
</a>
25.6.17.50 The ndbinfo pgman_time_track_stats Table
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045088278832">
</a>
<p>
This table provides information regarding the latency of disk
operations for NDB Cluster Disk Data tablespaces.
</p>
<p>
The
<code class="literal">
pgman_time_track_stats
</code>
table contains the
following columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
node_id
</code>
</p>
<p>
Unique node ID of this node in the cluster
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
block_number
</code>
</p>
<p>
Block number (from
<a class="link" href="mysql-cluster-ndbinfo-blocks.html" title="25.6.17.5 The ndbinfo blocks Table">
<code class="literal">
blocks
</code>
</a>
table)
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
block_instance
</code>
</p>
<p>
Block instance number
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
upper_bound
</code>
</p>
<p>
Upper bound
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
page_reads
</code>
</p>
<p>
Page read latency (ms)
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
page_writes
</code>
</p>
<p>
Page write latency (ms)
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
log_waits
</code>
</p>
<p>
Log wait latency (ms)
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
get_page
</code>
</p>
<p>
Latency of
<code class="literal">
get_page()
</code>
calls (ms)
</p>
</li>
</ul>
</div>
<h5>
<a name="idm46045088258064">
</a>
Notes
</h5>
<p>
The read latency (
<code class="literal">
page_reads
</code>
column) measures
the time from when the read request is sent to the file system
thread until the read is complete and has been reported back to
the execution thread. The write latency
(
<code class="literal">
page_writes
</code>
) is calculated in a similar
fashion. The size of the page read to or written from a Disk
Data tablespace is always 32 KB.
</p>
<p>
Log wait latency (
<code class="literal">
log_waits
</code>
column) is the
length of time a page write must wait for the undo log to be
flushed, which must be done prior to each page write.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/pluggable-storage-overview.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h2 class="title">
<a name="pluggable-storage-overview">
</a>
18.11 Overview of MySQL Storage Engine Architecture
</h2>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="pluggable-storage.html">
18.11.1 Pluggable Storage Engine Architecture
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="pluggable-storage-common-layer.html">
18.11.2 The Common Database Server Layer
</a>
</span>
</dt>
</dl>
</div>
<p>
The MySQL pluggable storage engine architecture enables a database
professional to select a specialized storage engine for a
particular application need while being completely shielded from
the need to manage any specific application coding requirements.
The MySQL server architecture isolates the application programmer
and DBA from all of the low-level implementation details at the
storage level, providing a consistent and easy application model
and API. Thus, although there are different capabilities across
different storage engines, the application is shielded from these
differences.
</p>
<p>
The MySQL pluggable storage engine architecture is shown in
<a class="xref" href="pluggable-storage-overview.html#mysql-architecture-diagram" title="Figure 18.3 MySQL Architecture with Pluggable Storage Engines">
Figure 18.3, “MySQL Architecture with Pluggable Storage Engines”
</a>
.
</p>
<div class="figure">
<a name="mysql-architecture-diagram">
</a>
<p class="title">
<b>
Figure 18.3 MySQL Architecture with Pluggable Storage Engines
</b>
</p>
<div class="figure-contents">
<div class="mediaobject">
<img alt="MySQL architecture diagram showing connectors, interfaces, pluggable storage engines, the file system with files and logs." src="images/mysql-architecture.png" style="width: 100%; max-width: 500px;"/>
</div>
</div>
</div>
<br class="figure-break"/>
<p>
The pluggable storage engine architecture provides a standard set
of management and support services that are common among all
underlying storage engines. The storage engines themselves are the
components of the database server that actually perform actions on
the underlying data that is maintained at the physical server
level.
</p>
<p>
This efficient and modular architecture provides huge benefits for
those wishing to specifically target a particular application
need—such as data warehousing, transaction processing, or
high availability situations—while enjoying the advantage of
utilizing a set of interfaces and services that are independent of
any one storage engine.
</p>
<p>
The application programmer and DBA interact with the MySQL
database through Connector APIs and service layers that are above
the storage engines. If application changes bring about
requirements that demand the underlying storage engine change, or
that one or more storage engines be added to support new needs, no
significant coding or process changes are required to make things
work. The MySQL server architecture shields the application from
the underlying complexity of the storage engine by presenting a
consistent and easy-to-use API that applies across storage
engines.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/x-plugin.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h2 class="title">
<a name="x-plugin">
</a>
22.5 X Plugin
</h2>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="x-plugin-checking-installation.html">
22.5.1 Checking X Plugin Installation
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="x-plugin-disabling.html">
22.5.2 Disabling X Plugin
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="x-plugin-encrypted-connections.html">
22.5.3 Using Encrypted Connections with X Plugin
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="x-plugin-sha2-cache-plugin.html">
22.5.4 Using X Plugin with the Caching SHA-2 Authentication Plugin
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="x-plugin-connection-compression.html">
22.5.5 Connection Compression with X Plugin
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="x-plugin-options-variables.html">
22.5.6 X Plugin Options and Variables
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="x-plugin-system-monitoring.html">
22.5.7 Monitoring X Plugin
</a>
</span>
</dt>
</dl>
</div>
<a class="indexterm" name="idm46045126714656">
</a>
<p>
This section explains how to use, configure and monitor X Plugin.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/partitioning-linear-hash.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="partitioning-linear-hash">
</a>
26.2.4.1 LINEAR HASH Partitioning
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045084270000">
</a>
<a class="indexterm" name="idm46045084268512">
</a>
<p>
MySQL also supports linear hashing, which differs from regular
hashing in that linear hashing utilizes a linear powers-of-two
algorithm whereas regular hashing employs the modulus of the
hashing function's value.
</p>
<p>
Syntactically, the only difference between linear-hash
partitioning and regular hashing is the addition of the
<code class="literal">
LINEAR
</code>
keyword in the
<code class="literal">
PARTITION
BY
</code>
clause, as shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa5402999"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> employees <span class="token punctuation">(</span>
id <span class="token datatype">INT</span> <span class="token operator">NOT</span> <span class="token boolean">NULL</span><span class="token punctuation">,</span>
fname <span class="token datatype">VARCHAR</span><span class="token punctuation">(</span><span class="token number">30</span><span class="token punctuation">)</span><span class="token punctuation">,</span>
lname <span class="token datatype">VARCHAR</span><span class="token punctuation">(</span><span class="token number">30</span><span class="token punctuation">)</span><span class="token punctuation">,</span>
hired <span class="token datatype">DATE</span> <span class="token operator">NOT</span> <span class="token boolean">NULL</span> <span class="token keyword">DEFAULT</span> <span class="token string">'1970-01-01'</span><span class="token punctuation">,</span>
separated <span class="token datatype">DATE</span> <span class="token operator">NOT</span> <span class="token boolean">NULL</span> <span class="token keyword">DEFAULT</span> <span class="token string">'9999-12-31'</span><span class="token punctuation">,</span>
job_code <span class="token datatype">INT</span><span class="token punctuation">,</span>
store_id <span class="token datatype">INT</span>
<span class="token punctuation">)</span>
<span class="token keyword">PARTITION</span> <span class="token keyword">BY</span> <span class="token keyword">LINEAR</span> <span class="token keyword">HASH</span><span class="token punctuation">(</span> <span class="token function">YEAR</span><span class="token punctuation">(</span>hired<span class="token punctuation">)</span> <span class="token punctuation">)</span>
<span class="token keyword">PARTITIONS</span> <span class="token number">4</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
Given an expression
<em class="replaceable">
<code>
expr
</code>
</em>
, the
partition in which the record is stored when linear hashing is
used is partition number
<em class="replaceable">
<code>
N
</code>
</em>
from
among
<em class="replaceable">
<code>
num
</code>
</em>
partitions, where
<em class="replaceable">
<code>
N
</code>
</em>
is derived according to the
following algorithm:
</p>
<div class="orderedlist">
<ol class="orderedlist" type="1">
<li class="listitem">
<p>
Find the next power of 2 greater than
<em class="replaceable">
<code>
num
</code>
</em>
. We call this value
<em class="replaceable">
<code>
V
</code>
</em>
; it can be calculated as:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-simple"><div class="docs-select-all right" id="sa36401969"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-simple"><em class="replaceable">V</em> <span class="token operator">=</span> POWER<span class="token punctuation">(</span>2<span class="token punctuation">,</span> CEILING<span class="token punctuation">(</span>LOG<span class="token punctuation">(</span>2<span class="token punctuation">,</span> <em class="replaceable">num</em><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">)</span></code></pre>
</div>
<p>
(Suppose that
<em class="replaceable">
<code>
num
</code>
</em>
is 13. Then
<a class="link" href="mathematical-functions.html#function_log">
<code class="literal">
LOG(2,13)
</code>
</a>
is
3.7004397181411.
<a class="link" href="mathematical-functions.html#function_ceiling">
<code class="literal">
CEILING(3.7004397181411)
</code>
</a>
is
4, and
<em class="replaceable">
<code>
V
</code>
</em>
=
<a class="link" href="mathematical-functions.html#function_power">
<code class="literal">
POWER(2,4)
</code>
</a>
, which is 16.)
</p>
</li>
<li class="listitem">
<p>
Set
<em class="replaceable">
<code>
N
</code>
</em>
=
<em class="replaceable">
<code>
F
</code>
</em>
(
<em class="replaceable">
<code>
column_list
</code>
</em>
)
& (
<em class="replaceable">
<code>
V
</code>
</em>
- 1).
</p>
</li>
<li class="listitem">
<p>
While
<em class="replaceable">
<code>
N
</code>
</em>
>=
<em class="replaceable">
<code>
num
</code>
</em>
:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Set
<em class="replaceable">
<code>
V
</code>
</em>
=
<em class="replaceable">
<code>
V
</code>
</em>
/ 2
</p>
</li>
<li class="listitem">
<p>
Set
<em class="replaceable">
<code>
N
</code>
</em>
=
<em class="replaceable">
<code>
N
</code>
</em>
&
(
<em class="replaceable">
<code>
V
</code>
</em>
- 1)
</p>
</li>
</ul>
</div>
</li>
</ol>
</div>
<p>
Suppose that the table
<code class="literal">
t1
</code>
, using linear
hash partitioning and having 6 partitions, is created using
this statement:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-simple"><div class="docs-select-all right" id="sa88938317"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-simple">CREATE TABLE t1 <span class="token punctuation">(</span>col1 INT<span class="token punctuation">,</span> col2 CHAR<span class="token punctuation">(</span>5<span class="token punctuation">)</span><span class="token punctuation">,</span> col3 DATE<span class="token punctuation">)</span>
PARTITION BY LINEAR HASH<span class="token punctuation">(</span> YEAR<span class="token punctuation">(</span>col3<span class="token punctuation">)</span> <span class="token punctuation">)</span>
PARTITIONS 6<span class="token punctuation">;</span></code></pre>
</div>
<p>
Now assume that you want to insert two records into
<code class="literal">
t1
</code>
having the
<code class="literal">
col3
</code>
column values
<code class="literal">
'2003-04-14'
</code>
and
<code class="literal">
'1998-10-19'
</code>
. The partition number for the
first of these is determined as follows:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-simple"><div class="docs-select-all right" id="sa15960152"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-simple"><em class="replaceable">V</em> <span class="token operator">=</span> POWER<span class="token punctuation">(</span>2<span class="token punctuation">,</span> CEILING<span class="token punctuation">(</span> LOG<span class="token punctuation">(</span>2<span class="token punctuation">,</span>6<span class="token punctuation">)</span> <span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token operator">=</span> 8
<em class="replaceable">N</em> <span class="token operator">=</span> YEAR<span class="token punctuation">(</span>'2003<span class="token operator">-</span>04<span class="token operator">-</span>14'<span class="token punctuation">)</span> <span class="token operator">&</span> <span class="token punctuation">(</span>8 <span class="token operator">-</span> 1<span class="token punctuation">)</span>
<span class="token operator">=</span> 2003 <span class="token operator">&</span> 7
<span class="token operator">=</span> 3
<span class="token punctuation">(</span><em>3 <span class="token operator">>=</span> 6 is FALSE<span class="token operator">:</span> record stored in partition <span class="token comment" spellcheck="true">#3</span></em><span class="token comment" spellcheck="true">)</span></code></pre>
</div>
<p>
The number of the partition where the second record is stored
is calculated as shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-simple"><div class="docs-select-all right" id="sa44788251"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-simple"><em class="replaceable">V</em> <span class="token operator">=</span> 8
<em class="replaceable">N</em> <span class="token operator">=</span> YEAR<span class="token punctuation">(</span>'1998<span class="token operator">-</span>10<span class="token operator">-</span>19'<span class="token punctuation">)</span> <span class="token operator">&</span> <span class="token punctuation">(</span>8 <span class="token operator">-</span> 1<span class="token punctuation">)</span>
<span class="token operator">=</span> 1998 <span class="token operator">&</span> 7
<span class="token operator">=</span> 6
<span class="token punctuation">(</span><em>6 <span class="token operator">>=</span> 6 is TRUE<span class="token operator">:</span> additional step required</em><span class="token punctuation">)</span>
<em class="replaceable">N</em> <span class="token operator">=</span> 6 <span class="token operator">&</span> <span class="token punctuation">(</span><span class="token punctuation">(</span>8 <span class="token operator">/</span> 2<span class="token punctuation">)</span> <span class="token operator">-</span> 1<span class="token punctuation">)</span>
<span class="token operator">=</span> 6 <span class="token operator">&</span> 3
<span class="token operator">=</span> 2
<span class="token punctuation">(</span><em>2 <span class="token operator">>=</span> 6 is FALSE<span class="token operator">:</span> record stored in partition <span class="token comment" spellcheck="true">#2</span></em><span class="token comment" spellcheck="true">)</span></code></pre>
</div>
<p>
The advantage in partitioning by linear hash is that the
adding, dropping, merging, and splitting of partitions is made
much faster, which can be beneficial when dealing with tables
containing extremely large amounts (terabytes) of data. The
disadvantage is that data is less likely to be evenly
distributed between partitions as compared with the
distribution obtained using regular hash partitioning.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/insert.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="insert">
</a>
15.2.7 INSERT Statement
</h3>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="insert-select.html">
15.2.7.1 INSERT ... SELECT Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="insert-on-duplicate.html">
15.2.7.2 INSERT ... ON DUPLICATE KEY UPDATE Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="insert-delayed.html">
15.2.7.3 INSERT DELAYED Statement
</a>
</span>
</dt>
</dl>
</div>
<a class="indexterm" name="idm46045182522016">
</a>
<a class="indexterm" name="idm46045182520944">
</a>
<a class="indexterm" name="idm46045182519872">
</a>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa43738595"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">INSERT</span> <span class="token punctuation">[</span><span class="token keyword">LOW_PRIORITY</span> <span class="token operator">|</span> <span class="token keyword">DELAYED</span> <span class="token operator">|</span> <span class="token keyword">HIGH_PRIORITY</span><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">IGNORE</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">INTO</span><span class="token punctuation">]</span> <em class="replaceable">tbl_name</em>
<span class="token punctuation">[</span><span class="token keyword">PARTITION</span> <span class="token punctuation">(</span><em class="replaceable">partition_name</em> <span class="token punctuation">[</span><span class="token punctuation">,</span> <em class="replaceable">partition_name</em><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">)</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token punctuation">(</span><em class="replaceable">col_name</em> <span class="token punctuation">[</span><span class="token punctuation">,</span> <em class="replaceable">col_name</em><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">)</span><span class="token punctuation">]</span>
{ {<span class="token keyword">VALUES</span> <span class="token operator">|</span> <span class="token keyword">VALUE</span>} <span class="token punctuation">(</span><em class="replaceable">value_list</em><span class="token punctuation">)</span> <span class="token punctuation">[</span><span class="token punctuation">,</span> <span class="token punctuation">(</span><em class="replaceable">value_list</em><span class="token punctuation">)</span><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> }
<span class="token punctuation">[</span><span class="token keyword">AS</span> <em class="replaceable">row_alias</em><span class="token punctuation">[</span><span class="token punctuation">(</span><em class="replaceable">col_alias</em> <span class="token punctuation">[</span><span class="token punctuation">,</span> <em class="replaceable">col_alias</em><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">)</span><span class="token punctuation">]</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">ON</span> <span class="token keyword">DUPLICATE</span> <span class="token keyword">KEY</span> <span class="token keyword">UPDATE</span> <em class="replaceable">assignment_list</em><span class="token punctuation">]</span>
<span class="token keyword">INSERT</span> <span class="token punctuation">[</span><span class="token keyword">LOW_PRIORITY</span> <span class="token operator">|</span> <span class="token keyword">DELAYED</span> <span class="token operator">|</span> <span class="token keyword">HIGH_PRIORITY</span><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">IGNORE</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">INTO</span><span class="token punctuation">]</span> <em class="replaceable">tbl_name</em>
<span class="token punctuation">[</span><span class="token keyword">PARTITION</span> <span class="token punctuation">(</span><em class="replaceable">partition_name</em> <span class="token punctuation">[</span><span class="token punctuation">,</span> <em class="replaceable">partition_name</em><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">)</span><span class="token punctuation">]</span>
<span class="token keyword">SET</span> <em class="replaceable">assignment_list</em>
<span class="token punctuation">[</span><span class="token keyword">AS</span> <em class="replaceable">row_alias</em><span class="token punctuation">[</span><span class="token punctuation">(</span><em class="replaceable">col_alias</em> <span class="token punctuation">[</span><span class="token punctuation">,</span> <em class="replaceable">col_alias</em><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">)</span><span class="token punctuation">]</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">ON</span> <span class="token keyword">DUPLICATE</span> <span class="token keyword">KEY</span> <span class="token keyword">UPDATE</span> <em class="replaceable">assignment_list</em><span class="token punctuation">]</span>
<span class="token keyword">INSERT</span> <span class="token punctuation">[</span><span class="token keyword">LOW_PRIORITY</span> <span class="token operator">|</span> <span class="token keyword">HIGH_PRIORITY</span><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">IGNORE</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token keyword">INTO</span><span class="token punctuation">]</span> <em class="replaceable">tbl_name</em>
<span class="token punctuation">[</span><span class="token keyword">PARTITION</span> <span class="token punctuation">(</span><em class="replaceable">partition_name</em> <span class="token punctuation">[</span><span class="token punctuation">,</span> <em class="replaceable">partition_name</em><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">)</span><span class="token punctuation">]</span>
<span class="token punctuation">[</span><span class="token punctuation">(</span><em class="replaceable">col_name</em> <span class="token punctuation">[</span><span class="token punctuation">,</span> <em class="replaceable">col_name</em><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">)</span><span class="token punctuation">]</span>
{ <span class="token keyword">SELECT</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span>
<span class="token operator">|</span> <span class="token keyword">TABLE</span> <span class="token keyword"><em class="replaceable">table_name</em></span>
<span class="token operator">|</span> <span class="token keyword">VALUES</span> <em class="replaceable">row_constructor_list</em>
}
<span class="token punctuation">[</span><span class="token keyword">ON</span> <span class="token keyword">DUPLICATE</span> <span class="token keyword">KEY</span> <span class="token keyword">UPDATE</span> <em class="replaceable">assignment_list</em><span class="token punctuation">]</span>
<span class="token keyword"><em class="replaceable">value</em></span>:
{<em class="replaceable">expr</em> <span class="token operator">|</span> <span class="token keyword">DEFAULT</span>}
<em class="replaceable">value_list</em>:
<span class="token keyword"><em class="replaceable">value</em></span> <span class="token punctuation">[</span><span class="token punctuation">,</span> <span class="token keyword"><em class="replaceable">value</em></span><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span>
<em class="replaceable">row_constructor_list</em>:
<span class="token keyword">ROW</span><span class="token punctuation">(</span><em class="replaceable">value_list</em><span class="token punctuation">)</span><span class="token punctuation">[</span><span class="token punctuation">,</span> <span class="token keyword">ROW</span><span class="token punctuation">(</span><em class="replaceable">value_list</em><span class="token punctuation">)</span><span class="token punctuation">]</span><span class="token punctuation">[</span><span class="token punctuation">,</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">]</span>
<em class="replaceable">assignment</em>:
<em class="replaceable">col_name</em> <span class="token operator">=</span>
<span class="token keyword"><em class="replaceable">value</em></span>
<span class="token operator">|</span> <span class="token punctuation">[</span><em class="replaceable">row_alias</em><span class="token punctuation">.</span><span class="token punctuation">]</span><em class="replaceable">col_name</em>
<span class="token operator">|</span> <span class="token punctuation">[</span><em class="replaceable">tbl_name</em><span class="token punctuation">.</span><span class="token punctuation">]</span><em class="replaceable">col_name</em>
<span class="token operator">|</span> <span class="token punctuation">[</span><em class="replaceable">row_alias</em><span class="token punctuation">.</span><span class="token punctuation">]</span><em class="replaceable">col_alias</em>
<em class="replaceable">assignment_list</em>:
<em class="replaceable">assignment</em> <span class="token punctuation">[</span><span class="token punctuation">,</span> <em class="replaceable">assignment</em><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span></code></pre>
</div>
<p>
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
inserts new rows into an
existing table. The
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
... VALUES
</code>
</a>
,
<a class="link" href="values.html" title="15.2.19 VALUES Statement">
<code class="literal">
INSERT ... VALUES
ROW()
</code>
</a>
, and
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT ... SET
</code>
</a>
forms of the statement insert rows based on explicitly specified
values. The
<a class="link" href="insert-select.html" title="15.2.7.1 INSERT ... SELECT Statement">
<code class="literal">
INSERT
... SELECT
</code>
</a>
form inserts rows selected from another table
or tables. You can also use
<a class="link" href="table.html" title="15.2.16 TABLE Statement">
<code class="literal">
INSERT ... TABLE
</code>
</a>
to insert rows from a single table.
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
with an
<code class="literal">
ON
DUPLICATE KEY UPDATE
</code>
clause enables existing rows to be
updated if a row to be inserted would cause a duplicate value in a
<code class="literal">
UNIQUE
</code>
index or
<code class="literal">
PRIMARY KEY
</code>
.
A row alias with one or more optional column aliases can be used
with
<code class="literal">
ON DUPLICATE KEY UPDATE
</code>
to refer to the
row to be inserted.
</p>
<p>
For additional information about
<a class="link" href="insert-select.html" title="15.2.7.1 INSERT ... SELECT Statement">
<code class="literal">
INSERT ...
SELECT
</code>
</a>
and
<a class="link" href="insert-on-duplicate.html" title="15.2.7.2 INSERT ... ON DUPLICATE KEY UPDATE Statement">
<code class="literal">
INSERT ... ON
DUPLICATE KEY UPDATE
</code>
</a>
, see
<a class="xref" href="insert-select.html" title="15.2.7.1 INSERT ... SELECT Statement">
Section 15.2.7.1, “INSERT ... SELECT Statement”
</a>
, and
<a class="xref" href="insert-on-duplicate.html" title="15.2.7.2 INSERT ... ON DUPLICATE KEY UPDATE Statement">
Section 15.2.7.2, “INSERT ... ON DUPLICATE KEY UPDATE Statement”
</a>
.
</p>
<p>
In MySQL 8.4, the
<code class="literal">
DELAYED
</code>
keyword
is accepted but ignored by the server. For the reasons for this,
see
<a class="xref" href="insert-delayed.html" title="15.2.7.3 INSERT DELAYED Statement">
Section 15.2.7.3, “INSERT DELAYED Statement”
</a>
,
</p>
<p>
Inserting into a table requires the
<a class="link" href="privileges-provided.html#priv_insert">
<code class="literal">
INSERT
</code>
</a>
privilege for the table. If
the
<code class="literal">
ON DUPLICATE KEY UPDATE
</code>
clause is used and
a duplicate key causes an
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
to
be performed instead, the statement requires the
<a class="link" href="privileges-provided.html#priv_update">
<code class="literal">
UPDATE
</code>
</a>
privilege for the columns to
be updated. For columns that are read but not modified you need
only the
<a class="link" href="privileges-provided.html#priv_select">
<code class="literal">
SELECT
</code>
</a>
privilege (such as
for a column referenced only on the right hand side of an
<em class="replaceable">
<code>
col_name
</code>
</em>
=
<em class="replaceable">
<code>
expr
</code>
</em>
assignment in an
<code class="literal">
ON DUPLICATE KEY UPDATE
</code>
clause).
</p>
<p>
When inserting into a partitioned table, you can control which
partitions and subpartitions accept new rows. The
<code class="literal">
PARTITION
</code>
clause takes a list of the
comma-separated names of one or more partitions or subpartitions
(or both) of the table. If any of the rows to be inserted by a
given
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
statement do not match
one of the partitions listed, the
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
statement fails with the
error
<span class="errortext">
Found a row not matching the given partition
set
</span>
. For more information and examples, see
<a class="xref" href="partitioning-selection.html" title="26.5 Partition Selection">
Section 26.5, “Partition Selection”
</a>
.
</p>
<p>
<em class="replaceable">
<code>
tbl_name
</code>
</em>
is the table into which rows
should be inserted. Specify the columns for which the statement
provides values as follows:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Provide a parenthesized list of comma-separated column names
following the table name. In this case, a value for each named
column must be provided by the
<code class="literal">
VALUES
</code>
list,
<a class="link" href="values.html" title="15.2.19 VALUES Statement">
<code class="literal">
VALUES ROW()
</code>
</a>
list, or
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
statement. For
the
<code class="literal">
INSERT TABLE
</code>
form, the number of
columns in the source table must match the number of columns
to be inserted.
</p>
</li>
<li class="listitem">
<p>
If you do not specify a list of column names for
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT ...
VALUES
</code>
</a>
or
<a class="link" href="insert-select.html" title="15.2.7.1 INSERT ... SELECT Statement">
<code class="literal">
INSERT ...
SELECT
</code>
</a>
, values for every column in the table must be
provided by the
<code class="literal">
VALUES
</code>
list,
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
statement, or
<a class="link" href="table.html" title="15.2.16 TABLE Statement">
<code class="literal">
TABLE
</code>
</a>
statement. If you do not
know the order of the columns in the table, use
<code class="literal">
DESCRIBE
<em class="replaceable">
<code>
tbl_name
</code>
</em>
</code>
to find out.
</p>
</li>
<li class="listitem">
<p>
A
<code class="literal">
SET
</code>
clause indicates columns explicitly
by name, together with the value to assign each one.
</p>
</li>
</ul>
</div>
<p>
Column values can be given in several ways:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
If strict SQL mode is not enabled, any column not explicitly
given a value is set to its default (explicit or implicit)
value. For example, if you specify a column list that does not
name all the columns in the table, unnamed columns are set to
their default values. Default value assignment is described in
<a class="xref" href="data-type-defaults.html" title="13.6 Data Type Default Values">
Section 13.6, “Data Type Default Values”
</a>
.
</p>
<a class="indexterm" name="idm46045182442928">
</a>
<p>
If strict SQL mode is enabled, an
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
statement generates an
error if it does not specify an explicit value for every
column that has no default value. See
<a class="xref" href="sql-mode.html" title="7.1.11 Server SQL Modes">
Section 7.1.11, “Server SQL Modes”
</a>
.
</p>
</li>
<li class="listitem">
<p>
If both the column list and the
<code class="literal">
VALUES
</code>
list
are empty,
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
creates a row
with each column set to its default value:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa87278878"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> <em class="replaceable">tbl_name</em> <span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token keyword">VALUES</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
If strict mode is not enabled, MySQL uses the implicit default
value for any column that has no explicitly defined default.
If strict mode is enabled, an error occurs if any column has
no default value.
</p>
</li>
<li class="listitem">
<p>
Use the keyword
<code class="literal">
DEFAULT
</code>
to set a column
explicitly to its default value. This makes it easier to write
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
statements that assign
values to all but a few columns, because it enables you to
avoid writing an incomplete
<code class="literal">
VALUES
</code>
list
that does not include a value for each column in the table.
Otherwise, you must provide the list of column names
corresponding to each value in the
<code class="literal">
VALUES
</code>
list.
</p>
</li>
<li class="listitem">
<p>
If a generated column is inserted into explicitly, the only
permitted value is
<code class="literal">
DEFAULT
</code>
. For information
about generated columns, see
<a class="xref" href="create-table-generated-columns.html" title="15.1.20.8 CREATE TABLE and Generated Columns">
Section 15.1.20.8, “CREATE TABLE and Generated Columns”
</a>
.
</p>
<a class="indexterm" name="idm46045182427488">
</a>
</li>
<li class="listitem">
<p>
In expressions, you can use
<a class="link" href="miscellaneous-functions.html#function_default">
<code class="literal">
DEFAULT(
<em class="replaceable">
<code>
col_name
</code>
</em>
)
</code>
</a>
to produce the default value for column
<em class="replaceable">
<code>
col_name
</code>
</em>
.
</p>
</li>
<li class="listitem">
<p>
Type conversion of an expression
<em class="replaceable">
<code>
expr
</code>
</em>
that provides a column value
might occur if the expression data type does not match the
column data type. Conversion of a given value can result in
different inserted values depending on the column type. For
example, inserting the string
<code class="literal">
'1999.0e-2'
</code>
into an
<a class="link" href="integer-types.html" title="13.1.2 Integer Types (Exact Value) - INTEGER, INT, SMALLINT, TINYINT, MEDIUMINT, BIGINT">
<code class="literal">
INT
</code>
</a>
,
<a class="link" href="floating-point-types.html" title="13.1.4 Floating-Point Types (Approximate Value) - FLOAT, DOUBLE">
<code class="literal">
FLOAT
</code>
</a>
,
<a class="link" href="fixed-point-types.html" title="13.1.3 Fixed-Point Types (Exact Value) - DECIMAL, NUMERIC">
<code class="literal">
DECIMAL(10,6)
</code>
</a>
, or
<a class="link" href="year.html" title="13.2.4 The YEAR Type">
<code class="literal">
YEAR
</code>
</a>
column inserts the value
<code class="literal">
1999
</code>
,
<code class="literal">
19.9921
</code>
,
<code class="literal">
19.992100
</code>
, or
<code class="literal">
1999
</code>
,
respectively. The value stored in the
<a class="link" href="integer-types.html" title="13.1.2 Integer Types (Exact Value) - INTEGER, INT, SMALLINT, TINYINT, MEDIUMINT, BIGINT">
<code class="literal">
INT
</code>
</a>
and
<a class="link" href="year.html" title="13.2.4 The YEAR Type">
<code class="literal">
YEAR
</code>
</a>
columns is
<code class="literal">
1999
</code>
because the string-to-number
conversion looks only at as much of the initial part of the
string as may be considered a valid integer or year. For the
<a class="link" href="floating-point-types.html" title="13.1.4 Floating-Point Types (Approximate Value) - FLOAT, DOUBLE">
<code class="literal">
FLOAT
</code>
</a>
and
<a class="link" href="fixed-point-types.html" title="13.1.3 Fixed-Point Types (Exact Value) - DECIMAL, NUMERIC">
<code class="literal">
DECIMAL
</code>
</a>
columns, the
string-to-number conversion considers the entire string a
valid numeric value.
</p>
</li>
<li class="listitem">
<p>
An expression
<em class="replaceable">
<code>
expr
</code>
</em>
can refer to any
column that was set earlier in a value list. For example, you
can do this because the value for
<code class="literal">
col2
</code>
refers to
<code class="literal">
col1
</code>
, which has previously been
assigned:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa48049138"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> <em class="replaceable">tbl_name</em> <span class="token punctuation">(</span>col1<span class="token punctuation">,</span>col2<span class="token punctuation">)</span> <span class="token keyword">VALUES</span><span class="token punctuation">(</span><span class="token number">15</span><span class="token punctuation">,</span>col1<span class="token operator">*</span><span class="token number">2</span><span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
But the following is not legal, because the value for
<code class="literal">
col1
</code>
refers to
<code class="literal">
col2
</code>
,
which is assigned after
<code class="literal">
col1
</code>
:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa75007432"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> <em class="replaceable">tbl_name</em> <span class="token punctuation">(</span>col1<span class="token punctuation">,</span>col2<span class="token punctuation">)</span> <span class="token keyword">VALUES</span><span class="token punctuation">(</span>col2<span class="token operator">*</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token number">15</span><span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
An exception occurs for columns that contain
<code class="literal">
AUTO_INCREMENT
</code>
values. Because
<code class="literal">
AUTO_INCREMENT
</code>
values are generated after
other value assignments, any reference to an
<code class="literal">
AUTO_INCREMENT
</code>
column in the assignment
returns a
<code class="literal">
0
</code>
.
</p>
</li>
</ul>
</div>
<p>
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
statements that use
<code class="literal">
VALUES
</code>
syntax can insert multiple rows. To do
this, include multiple lists of comma-separated column values,
with lists enclosed within parentheses and separated by commas.
Example:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa99025408"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> <em class="replaceable">tbl_name</em> <span class="token punctuation">(</span>a<span class="token punctuation">,</span>b<span class="token punctuation">,</span>c<span class="token punctuation">)</span>
<span class="token keyword">VALUES</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token number">3</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token punctuation">(</span><span class="token number">4</span><span class="token punctuation">,</span><span class="token number">5</span><span class="token punctuation">,</span><span class="token number">6</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token punctuation">(</span><span class="token number">7</span><span class="token punctuation">,</span><span class="token number">8</span><span class="token punctuation">,</span><span class="token number">9</span><span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
Each values list must contain exactly as many values as are to be
inserted per row. The following statement is invalid because it
contains one list of nine values, rather than three lists of three
values each:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa63790687"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> <em class="replaceable">tbl_name</em> <span class="token punctuation">(</span>a<span class="token punctuation">,</span>b<span class="token punctuation">,</span>c<span class="token punctuation">)</span> <span class="token keyword">VALUES</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token number">3</span><span class="token punctuation">,</span><span class="token number">4</span><span class="token punctuation">,</span><span class="token number">5</span><span class="token punctuation">,</span><span class="token number">6</span><span class="token punctuation">,</span><span class="token number">7</span><span class="token punctuation">,</span><span class="token number">8</span><span class="token punctuation">,</span><span class="token number">9</span><span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
<code class="literal">
VALUE
</code>
is a synonym for
<code class="literal">
VALUES
</code>
in this context. Neither implies
anything about the number of values lists, nor about the number of
values per list. Either may be used whether there is a single
values list or multiple lists, and regardless of the number of
values per list.
</p>
<p>
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
statements using
<a class="link" href="values.html" title="15.2.19 VALUES Statement">
<code class="literal">
VALUES ROW()
</code>
</a>
syntax can also insert multiple rows. In this case, each value
list must be contained within a
<code class="literal">
ROW()
</code>
(row
constructor), like this:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa75861128"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> <em class="replaceable">tbl_name</em> <span class="token punctuation">(</span>a<span class="token punctuation">,</span>b<span class="token punctuation">,</span>c<span class="token punctuation">)</span>
<span class="token keyword">VALUES</span> <span class="token keyword">ROW</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token number">3</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token keyword">ROW</span><span class="token punctuation">(</span><span class="token number">4</span><span class="token punctuation">,</span><span class="token number">5</span><span class="token punctuation">,</span><span class="token number">6</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token keyword">ROW</span><span class="token punctuation">(</span><span class="token number">7</span><span class="token punctuation">,</span><span class="token number">8</span><span class="token punctuation">,</span><span class="token number">9</span><span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
The affected-rows value for an
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
can be obtained using the
<a class="link" href="information-functions.html#function_row-count">
<code class="literal">
ROW_COUNT()
</code>
</a>
SQL function or the
<a class="ulink" href="/doc/c-api/8.4/en/mysql-affected-rows.html" target="_top">
<code class="literal">
mysql_affected_rows()
</code>
</a>
C API
function. See
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
, and
<a class="ulink" href="/doc/c-api/8.4/en/mysql-affected-rows.html" target="_top">
mysql_affected_rows()
</a>
.
</p>
<p>
If you use
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT ...
VALUES
</code>
</a>
or
<code class="literal">
INSERT ... VALUES ROW()
</code>
with multiple value lists, or
<a class="link" href="insert-select.html" title="15.2.7.1 INSERT ... SELECT Statement">
<code class="literal">
INSERT ...
SELECT
</code>
</a>
or
<code class="literal">
INSERT ... TABLE
</code>
, the
statement returns an information string in this format:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-none"><div class="docs-select-all right" id="sa56734347"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-none">Records: <em class="replaceable">N1</em> Duplicates: <em class="replaceable">N2</em> Warnings: <em class="replaceable">N3</em></code></pre>
</div>
<a class="indexterm" name="idm46045182369760">
</a>
<p>
If you are using the C API, the information string can be obtained
by invoking the
<a class="ulink" href="/doc/c-api/8.4/en/mysql-info.html" target="_top">
<code class="literal">
mysql_info()
</code>
</a>
function. See
<a class="ulink" href="/doc/c-api/8.4/en/mysql-info.html" target="_top">
mysql_info()
</a>
.
</p>
<p>
<code class="literal">
Records
</code>
indicates the number of rows processed
by the statement. (This is not necessarily the number of rows
actually inserted because
<code class="literal">
Duplicates
</code>
can be
nonzero.)
<code class="literal">
Duplicates
</code>
indicates the number of
rows that could not be inserted because they would duplicate some
existing unique index value.
<code class="literal">
Warnings
</code>
indicates
the number of attempts to insert column values that were
problematic in some way. Warnings can occur under any of the
following conditions:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Inserting
<code class="literal">
NULL
</code>
into a column that has been
declared
<code class="literal">
NOT NULL
</code>
. For multiple-row
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
statements or
<a class="link" href="insert-select.html" title="15.2.7.1 INSERT ... SELECT Statement">
<code class="literal">
INSERT INTO ...
SELECT
</code>
</a>
statements, the column is set to the implicit
default value for the column data type. This is
<code class="literal">
0
</code>
for numeric types, the empty string
(
<code class="literal">
''
</code>
) for string types, and the
<span class="quote">
“
<span class="quote">
zero
</span>
”
</span>
value for date and time types.
<a class="link" href="insert-select.html" title="15.2.7.1 INSERT ... SELECT Statement">
<code class="literal">
INSERT INTO ...
SELECT
</code>
</a>
statements are handled the same way as
multiple-row inserts because the server does not examine the
result set from the
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
to
see whether it returns a single row. (For a single-row
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
, no warning occurs when
<code class="literal">
NULL
</code>
is inserted into a
<code class="literal">
NOT
NULL
</code>
column. Instead, the statement fails with an
error.)
</p>
</li>
<li class="listitem">
<p>
Setting a numeric column to a value that lies outside the
column range. The value is clipped to the closest endpoint of
the range.
</p>
</li>
<li class="listitem">
<p>
Assigning a value such as
<code class="literal">
'10.34 a'
</code>
to a
numeric column. The trailing nonnumeric text is stripped off
and the remaining numeric part is inserted. If the string
value has no leading numeric part, the column is set to
<code class="literal">
0
</code>
.
</p>
</li>
<li class="listitem">
<p>
Inserting a string into a string column
(
<a class="link" href="char.html" title="13.3.2 The CHAR and VARCHAR Types">
<code class="literal">
CHAR
</code>
</a>
,
<a class="link" href="char.html" title="13.3.2 The CHAR and VARCHAR Types">
<code class="literal">
VARCHAR
</code>
</a>
,
<a class="link" href="blob.html" title="13.3.4 The BLOB and TEXT Types">
<code class="literal">
TEXT
</code>
</a>
, or
<a class="link" href="blob.html" title="13.3.4 The BLOB and TEXT Types">
<code class="literal">
BLOB
</code>
</a>
) that exceeds the column
maximum length. The value is truncated to the column maximum
length.
</p>
</li>
<li class="listitem">
<p>
Inserting a value into a date or time column that is illegal
for the data type. The column is set to the appropriate zero
value for the type.
</p>
</li>
<li class="listitem">
<p>
For
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
examples involving
<code class="literal">
AUTO_INCREMENT
</code>
column values, see
<a class="xref" href="example-auto-increment.html" title="5.6.9 Using AUTO_INCREMENT">
Section 5.6.9, “Using AUTO_INCREMENT”
</a>
.
</p>
<a class="indexterm" name="idm46045182336576">
</a>
<a class="indexterm" name="idm46045182335504">
</a>
<p>
If
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
inserts a row into a
table that has an
<code class="literal">
AUTO_INCREMENT
</code>
column,
you can find the value used for that column by using the
<a class="link" href="information-functions.html#function_last-insert-id">
<code class="literal">
LAST_INSERT_ID()
</code>
</a>
SQL function
or the
<a class="ulink" href="/doc/c-api/8.4/en/mysql-insert-id.html" target="_top">
<code class="literal">
mysql_insert_id()
</code>
</a>
C API
function.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
These two functions do not always behave identically. The
behavior of
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
statements
with respect to
<code class="literal">
AUTO_INCREMENT
</code>
columns is
discussed further in
<a class="xref" href="information-functions.html" title="14.15 Information Functions">
Section 14.15, “Information Functions”
</a>
, and
<a class="ulink" href="/doc/c-api/8.4/en/mysql-insert-id.html" target="_top">
mysql_insert_id()
</a>
.
</p>
</div>
</li>
</ul>
</div>
<p>
The
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
statement supports the
following modifiers:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
If you use the
<code class="literal">
LOW_PRIORITY
</code>
modifier,
execution of the
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
is
delayed until no other clients are reading from the table.
This includes other clients that began reading while existing
clients are reading, and while the
<code class="literal">
INSERT
LOW_PRIORITY
</code>
statement is waiting. It is possible,
therefore, for a client that issues an
<code class="literal">
INSERT
LOW_PRIORITY
</code>
statement to wait for a very long time.
</p>
<a class="indexterm" name="idm46045182318576">
</a>
<p>
<code class="literal">
LOW_PRIORITY
</code>
affects only storage engines
that use only table-level locking (such as
<code class="literal">
MyISAM
</code>
,
<code class="literal">
MEMORY
</code>
, and
<code class="literal">
MERGE
</code>
).
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
<code class="literal">
LOW_PRIORITY
</code>
should normally not be used
with
<code class="literal">
MyISAM
</code>
tables because doing so
disables concurrent inserts. See
<a class="xref" href="concurrent-inserts.html" title="10.11.3 Concurrent Inserts">
Section 10.11.3, “Concurrent Inserts”
</a>
.
</p>
</div>
</li>
<li class="listitem">
<p>
If you specify
<code class="literal">
HIGH_PRIORITY
</code>
, it overrides
the effect of the
<a class="link" href="server-system-variables.html#sysvar_low_priority_updates">
<code class="option">
--low-priority-updates
</code>
</a>
option
if the server was started with that option. It also causes
concurrent inserts not to be used. See
<a class="xref" href="concurrent-inserts.html" title="10.11.3 Concurrent Inserts">
Section 10.11.3, “Concurrent Inserts”
</a>
.
</p>
<a class="indexterm" name="idm46045182307440">
</a>
<p>
<code class="literal">
HIGH_PRIORITY
</code>
affects only storage engines
that use only table-level locking (such as
<code class="literal">
MyISAM
</code>
,
<code class="literal">
MEMORY
</code>
, and
<code class="literal">
MERGE
</code>
).
</p>
</li>
<li class="listitem">
<p>
If you use the
<code class="literal">
IGNORE
</code>
modifier, ignorable
errors that occur while executing the
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
statement are ignored.
For example, without
<code class="literal">
IGNORE
</code>
, a row that
duplicates an existing
<code class="literal">
UNIQUE
</code>
index or
<code class="literal">
PRIMARY KEY
</code>
value in the table causes a
duplicate-key error and the statement is aborted. With
<code class="literal">
IGNORE
</code>
, the row is discarded and no error
occurs. Ignored errors generate warnings instead.
</p>
<a class="indexterm" name="idm46045182296672">
</a>
<p>
<a class="indexterm" name="idm46045182294928">
</a>
<code class="literal">
IGNORE
</code>
has a similar effect on inserts into
partitioned tables where no partition matching a given value
is found. Without
<code class="literal">
IGNORE
</code>
, such
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
statements are aborted
with an error. When
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
IGNORE
</code>
</a>
is used, the insert operation fails silently
for rows containing the unmatched value, but inserts rows that
are matched. For an example, see
<a class="xref" href="partitioning-list.html" title="26.2.2 LIST Partitioning">
Section 26.2.2, “LIST Partitioning”
</a>
.
</p>
<p>
Data conversions that would trigger errors abort the statement
if
<code class="literal">
IGNORE
</code>
is not specified. With
<code class="literal">
IGNORE
</code>
, invalid values are adjusted to the
closest values and inserted; warnings are produced but the
statement does not abort. You can determine with the
<a class="ulink" href="/doc/c-api/8.4/en/mysql-info.html" target="_top">
<code class="literal">
mysql_info()
</code>
</a>
C API function
how many rows were actually inserted into the table.
</p>
<p>
For more information, see
<a class="xref" href="sql-mode.html#ignore-effect-on-execution" title="The Effect of IGNORE on Statement Execution">
The Effect of IGNORE on Statement Execution
</a>
.
</p>
<p>
You can use
<a class="link" href="replace.html" title="15.2.12 REPLACE Statement">
<code class="literal">
REPLACE
</code>
</a>
instead of
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
</code>
</a>
to overwrite old rows.
<a class="link" href="replace.html" title="15.2.12 REPLACE Statement">
<code class="literal">
REPLACE
</code>
</a>
is the counterpart to
<a class="link" href="insert.html" title="15.2.7 INSERT Statement">
<code class="literal">
INSERT
IGNORE
</code>
</a>
in the treatment of new rows that contain
unique key values that duplicate old rows: The new rows
replace the old rows rather than being discarded. See
<a class="xref" href="replace.html" title="15.2.12 REPLACE Statement">
Section 15.2.12, “REPLACE Statement”
</a>
.
</p>
</li>
<li class="listitem">
<p>
If you specify
<code class="literal">
ON DUPLICATE KEY UPDATE
</code>
, and
a row is inserted that would cause a duplicate value in a
<code class="literal">
UNIQUE
</code>
index or
<code class="literal">
PRIMARY
KEY
</code>
, an
<a class="link" href="update.html" title="15.2.17 UPDATE Statement">
<code class="literal">
UPDATE
</code>
</a>
of the
old row occurs. The affected-rows value per row is 1 if the
row is inserted as a new row, 2 if an existing row is updated,
and 0 if an existing row is set to its current values. If you
specify the
<code class="literal">
CLIENT_FOUND_ROWS
</code>
flag to the
<a class="ulink" href="/doc/c-api/8.4/en/mysql-real-connect.html" target="_top">
<code class="literal">
mysql_real_connect()
</code>
</a>
C API
function when connecting to
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
, the
affected-rows value is 1 (not 0) if an existing row is set to
its current values. See
<a class="xref" href="insert-on-duplicate.html" title="15.2.7.2 INSERT ... ON DUPLICATE KEY UPDATE Statement">
Section 15.2.7.2, “INSERT ... ON DUPLICATE KEY UPDATE Statement”
</a>
.
</p>
<a class="indexterm" name="idm46045182269184">
</a>
</li>
<li class="listitem">
<p>
<a class="link" href="insert-delayed.html" title="15.2.7.3 INSERT DELAYED Statement">
<code class="literal">
INSERT DELAYED
</code>
</a>
was deprecated
in MySQL 5.6, and is scheduled for eventual removal. In MySQL
8.4, the
<code class="literal">
DELAYED
</code>
modifier is
accepted but ignored. Use
<code class="literal">
INSERT
</code>
(without
<code class="literal">
DELAYED
</code>
) instead. See
<a class="xref" href="insert-delayed.html" title="15.2.7.3 INSERT DELAYED Statement">
Section 15.2.7.3, “INSERT DELAYED Statement”
</a>
.
</p>
<a class="indexterm" name="idm46045182262720">
</a>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-replication-applier-status-by-worker-table.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="performance-schema-replication-applier-status-by-worker-table">
</a>
29.12.11.7 The replication_applier_status_by_worker Table
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045071337872">
</a>
<a class="indexterm" name="idm46045071336368">
</a>
<p>
This table provides details of the transactions handled by
applier threads on a replica or Group Replication group
member. For a single-threaded replica, data is shown for the
replica's single applier thread. For a multithreaded
replica, data is shown individually for each applier thread.
The applier threads on a multithreaded replica are sometimes
called workers. The number of applier threads on a replica or
Group Replication group member is set by the
<a class="link" href="replication-options-replica.html#sysvar_replica_parallel_workers">
<code class="literal">
replica_parallel_workers
</code>
</a>
system variable, which is set to zero for a single-threaded
replica. A multithreaded replica also has a coordinator thread
to manage the applier threads, and the status of this thread
is shown in the
<a class="link" href="performance-schema-replication-applier-status-by-coordinator-table.html" title="29.12.11.6 The replication_applier_status_by_coordinator Table">
<code class="literal">
replication_applier_status_by_coordinator
</code>
</a>
table.
</p>
<p>
All error codes and messages displayed in the columns relating
to errors correspond to error values listed in
<a class="ulink" href="/doc/mysql-errors/8.4/en/server-error-reference.html" target="_top">
Server Error Message Reference
</a>
.
</p>
<p>
When the Performance Schema is disabled, local timing
information is not collected, so the fields showing the start
and end timestamps for applied transactions are zero. The
start timestamps in this table refer to when the worker
started applying the first event, and the end timestamps refer
to when the last event of the transaction was applied.
</p>
<p>
When a replica is restarted by a
<a class="link" href="start-replica.html" title="15.4.2.4 START REPLICA Statement">
<code class="literal">
START
REPLICA
</code>
</a>
statement, the columns beginning
<code class="literal">
APPLYING_TRANSACTION
</code>
are reset.
</p>
<p>
The
<a class="link" href="performance-schema-replication-applier-status-by-worker-table.html" title="29.12.11.7 The replication_applier_status_by_worker Table">
<code class="literal">
replication_applier_status_by_worker
</code>
</a>
table has these columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
CHANNEL_NAME
</code>
</p>
<p>
The replication channel which this row is displaying.
There is always a default replication channel, and more
replication channels can be added. See
<a class="xref" href="replication-channels.html" title="19.2.2 Replication Channels">
Section 19.2.2, “Replication Channels”
</a>
for more
information.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
WORKER_ID
</code>
</p>
<p>
The worker identifier (same value as the
<code class="literal">
id
</code>
column in the
<code class="literal">
mysql.slave_worker_info
</code>
table). After
<a class="link" href="stop-replica.html" title="15.4.2.5 STOP REPLICA Statement">
<code class="literal">
STOP
REPLICA
</code>
</a>
, the
<code class="literal">
THREAD_ID
</code>
column
becomes
<code class="literal">
NULL
</code>
, but the
<code class="literal">
WORKER_ID
</code>
value is preserved.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
THREAD_ID
</code>
</p>
<p>
The worker thread ID.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SERVICE_STATE
</code>
</p>
<p>
<code class="literal">
ON
</code>
(thread exists and is active or
idle) or
<code class="literal">
OFF
</code>
(thread no longer exists).
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LAST_ERROR_NUMBER
</code>
,
<code class="literal">
LAST_ERROR_MESSAGE
</code>
</p>
<p>
The error number and error message of the most recent
error that caused the worker thread to stop. An error
number of 0 and message of the empty string mean
<span class="quote">
“
<span class="quote">
no
error
</span>
”
</span>
. If the
<code class="literal">
LAST_ERROR_MESSAGE
</code>
value is not empty,
the error values also appear in the replica's error
log.
</p>
<p>
Issuing
<a class="link" href="reset-binary-logs-and-gtids.html" title="15.4.1.2 RESET BINARY LOGS AND GTIDS Statement">
<code class="literal">
RESET BINARY LOGS AND
GTIDS
</code>
</a>
or
<a class="link" href="reset-replica.html" title="15.4.2.3 RESET REPLICA Statement">
<code class="literal">
RESET
REPLICA
</code>
</a>
resets the values shown in these
columns.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LAST_ERROR_TIMESTAMP
</code>
</p>
<p>
A timestamp in
<code class="literal">
'
<em class="replaceable">
<code>
YYYY-MM-DD
hh:mm:ss
</code>
</em>
[.
<em class="replaceable">
<code>
fraction
</code>
</em>
]'
</code>
format that shows when the most recent worker error
occurred.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LAST_APPLIED_TRANSACTION
</code>
</p>
<p>
The global transaction ID (GTID) of the last transaction
applied by this worker.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LAST_APPLIED_TRANSACTION_ORIGINAL_COMMIT_TIMESTAMP
</code>
</p>
<p>
A timestamp in
<code class="literal">
'
<em class="replaceable">
<code>
YYYY-MM-DD
hh:mm:ss
</code>
</em>
[.
<em class="replaceable">
<code>
fraction
</code>
</em>
]'
</code>
format that shows when the last transaction applied by
this worker was committed on the original source.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LAST_APPLIED_TRANSACTION_IMMEDIATE_COMMIT_TIMESTAMP
</code>
</p>
<p>
A timestamp in
<code class="literal">
'
<em class="replaceable">
<code>
YYYY-MM-DD
hh:mm:ss
</code>
</em>
[.
<em class="replaceable">
<code>
fraction
</code>
</em>
]'
</code>
format that shows when the last transaction applied by
this worker was committed on the immediate source.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LAST_APPLIED_TRANSACTION_START_APPLY_TIMESTAMP
</code>
</p>
<p>
A timestamp in
<code class="literal">
'
<em class="replaceable">
<code>
YYYY-MM-DD
hh:mm:ss
</code>
</em>
[.
<em class="replaceable">
<code>
fraction
</code>
</em>
]'
</code>
format that shows when this worker started applying the
last applied transaction.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LAST_APPLIED_TRANSACTION_END_APPLY_TIMESTAMP
</code>
</p>
<p>
A timestamp in
<code class="literal">
'
<em class="replaceable">
<code>
YYYY-MM-DD
hh:mm:ss
</code>
</em>
[.
<em class="replaceable">
<code>
fraction
</code>
</em>
]'
</code>
format that shows when this worker finished applying the
last applied transaction.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
APPLYING_TRANSACTION
</code>
</p>
<p>
The global transaction ID (GTID) of the transaction this
worker is currently applying.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
APPLYING_TRANSACTION_ORIGINAL_COMMIT_TIMESTAMP
</code>
</p>
<p>
A timestamp in
<code class="literal">
'
<em class="replaceable">
<code>
YYYY-MM-DD
hh:mm:ss
</code>
</em>
[.
<em class="replaceable">
<code>
fraction
</code>
</em>
]'
</code>
format that shows when the transaction this worker is
currently applying was committed on the original source.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
APPLYING_TRANSACTION_IMMEDIATE_COMMIT_TIMESTAMP
</code>
</p>
<p>
A timestamp in
<code class="literal">
'
<em class="replaceable">
<code>
YYYY-MM-DD
hh:mm:ss
</code>
</em>
[.
<em class="replaceable">
<code>
fraction
</code>
</em>
]'
</code>
format that shows when the transaction this worker is
currently applying was committed on the immediate source.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
APPLYING_TRANSACTION_START_APPLY_TIMESTAMP
</code>
</p>
<p>
A timestamp in
<code class="literal">
'
<em class="replaceable">
<code>
YYYY-MM-DD
hh:mm:ss
</code>
</em>
[.
<em class="replaceable">
<code>
fraction
</code>
</em>
]'
</code>
format that shows when this worker started its first
attempt to apply the transaction that is currently being
applied.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LAST_APPLIED_TRANSACTION_RETRIES_COUNT
</code>
</p>
<p>
The number of times the last applied transaction was
retried by the worker after the first attempt. If the
transaction was applied at the first attempt, this number
is zero.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LAST_APPLIED_TRANSACTION_LAST_TRANSIENT_ERROR_NUMBER
</code>
</p>
<p>
The error number of the last transient error that caused
the transaction to be retried.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LAST_APPLIED_TRANSACTION_LAST_TRANSIENT_ERROR_MESSAGE
</code>
</p>
<p>
The message text for the last transient error that caused
the transaction to be retried.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LAST_APPLIED_TRANSACTION_LAST_TRANSIENT_ERROR_TIMESTAMP
</code>
</p>
<p>
A timestamp in
<code class="literal">
'
<em class="replaceable">
<code>
YYYY-MM-DD
hh:mm:ss
</code>
</em>
[.
<em class="replaceable">
<code>
fraction
</code>
</em>
]'
</code>
format for the last transient error that caused the
transaction to be retried.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
APPLYING_TRANSACTION_RETRIES_COUNT
</code>
</p>
<p>
The number of times the transaction that is currently
being applied was retried until this moment. If the
transaction was applied at the first attempt, this number
is zero.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
APPLYING_TRANSACTION_LAST_TRANSIENT_ERROR_NUMBER
</code>
</p>
<p>
The error number of the last transient error that caused
the current transaction to be retried.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
APPLYING_TRANSACTION_LAST_TRANSIENT_ERROR_MESSAGE
</code>
</p>
<p>
The message text for the last transient error that caused
the current transaction to be retried.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
APPLYING_TRANSACTION_LAST_TRANSIENT_ERROR_TIMESTAMP
</code>
</p>
<p>
A timestamp in
<code class="literal">
'
<em class="replaceable">
<code>
YYYY-MM-DD
hh:mm:ss
</code>
</em>
[.
<em class="replaceable">
<code>
fraction
</code>
</em>
]'
</code>
format for the last transient error that caused the
current transaction to be retried.
</p>
</li>
</ul>
</div>
<p>
The
<a class="link" href="performance-schema-replication-applier-status-by-worker-table.html" title="29.12.11.7 The replication_applier_status_by_worker Table">
<code class="literal">
replication_applier_status_by_worker
</code>
</a>
table has these indexes:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Primary key on (
<code class="literal">
CHANNEL_NAME
</code>
,
<code class="literal">
WORKER_ID
</code>
)
</p>
</li>
<li class="listitem">
<p>
Index on (
<code class="literal">
THREAD_ID
</code>
)
</p>
</li>
</ul>
</div>
<p>
The following table shows the correspondence between
<a class="link" href="performance-schema-replication-applier-status-by-worker-table.html" title="29.12.11.7 The replication_applier_status_by_worker Table">
<code class="literal">
replication_applier_status_by_worker
</code>
</a>
columns and
<a class="link" href="show-replica-status.html" title="15.7.7.35 SHOW REPLICA STATUS Statement">
<code class="literal">
SHOW
REPLICA STATUS
</code>
</a>
columns.
</p>
<div class="informaltable">
<table summary="Correspondence between replication_applier_status_by_worker columns and SHOW REPLICA STATUS columns">
<colgroup>
<col style="width: 60%"/>
<col style="width: 40%"/>
</colgroup>
<thead>
<tr>
<th>
<code class="literal">
replication_applier_status_by_worker
</code>
Column
</th>
<th>
<code class="literal">
SHOW REPLICA STATUS
</code>
Column
</th>
</tr>
</thead>
<tbody>
<tr>
<td>
<code class="literal">
WORKER_ID
</code>
</td>
<td>
None
</td>
</tr>
<tr>
<td>
<code class="literal">
THREAD_ID
</code>
</td>
<td>
None
</td>
</tr>
<tr>
<td>
<code class="literal">
SERVICE_STATE
</code>
</td>
<td>
None
</td>
</tr>
<tr>
<td>
<code class="literal">
LAST_ERROR_NUMBER
</code>
</td>
<td>
<code class="literal">
Last_SQL_Errno
</code>
</td>
</tr>
<tr>
<td>
<code class="literal">
LAST_ERROR_MESSAGE
</code>
</td>
<td>
<code class="literal">
Last_SQL_Error
</code>
</td>
</tr>
<tr>
<td>
<code class="literal">
LAST_ERROR_TIMESTAMP
</code>
</td>
<td>
<code class="literal">
Last_SQL_Error_Timestamp
</code>
</td>
</tr>
</tbody>
</table>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/system-variable-privileges.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="system-variable-privileges">
</a>
7.1.9.1 System Variable Privileges
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045266647968">
</a>
<a class="indexterm" name="idm46045266646480">
</a>
<a class="indexterm" name="idm46045266645408">
</a>
<a class="indexterm" name="idm46045266644336">
</a>
<a class="indexterm" name="idm46045266643248">
</a>
<a class="indexterm" name="idm46045266642176">
</a>
<a class="indexterm" name="idm46045266641104">
</a>
<a class="indexterm" name="idm46045266640016">
</a>
<p>
A system variable can have a global value that affects server
operation as a whole, a session value that affects only the
current session, or both:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
For dynamic system variables, the
<a class="link" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
<code class="literal">
SET
</code>
</a>
statement can be used to change their global or session
runtime value (or both), to affect operation of the current
server instance. (For information about dynamic variables,
see
<a class="xref" href="dynamic-system-variables.html" title="7.1.9.2 Dynamic System Variables">
Section 7.1.9.2, “Dynamic System Variables”
</a>
.)
</p>
</li>
<li class="listitem">
<p>
For certain global system variables,
<a class="link" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
<code class="literal">
SET
</code>
</a>
can be used to persist their value to the
<code class="filename">
mysqld-auto.cnf
</code>
file in the data
directory, to affect server operation for subsequent
startups. (For information about persisting system variables
and the
<code class="filename">
mysqld-auto.cnf
</code>
file, see
<a class="xref" href="persisted-system-variables.html" title="7.1.9.3 Persisted System Variables">
Section 7.1.9.3, “Persisted System Variables”
</a>
.)
</p>
</li>
<li class="listitem">
<p>
For persisted global system variables,
<a class="link" href="reset-persist.html" title="15.7.8.7 RESET PERSIST Statement">
<code class="literal">
RESET PERSIST
</code>
</a>
can be used to
remove their value from
<code class="filename">
mysqld-auto.cnf
</code>
, to affect server
operation for subsequent startups.
</p>
</li>
</ul>
</div>
<p>
This section describes the privileges required for operations
that assign values to system variables at runtime. This includes
operations that affect runtime values, and operations that
persist values.
</p>
<p>
To set a global system variable, use a
<a class="link" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
<code class="literal">
SET
</code>
</a>
statement with the appropriate keyword. These privileges apply:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
To set a global system variable runtime value, use the
<a class="link" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
<code class="literal">
SET
GLOBAL
</code>
</a>
statement, which requires the
<a class="link" href="privileges-provided.html#priv_system-variables-admin">
<code class="literal">
SYSTEM_VARIABLES_ADMIN
</code>
</a>
privilege (or the deprecated
<a class="link" href="privileges-provided.html#priv_super">
<code class="literal">
SUPER
</code>
</a>
privilege).
</p>
</li>
<li class="listitem">
<p>
To persist a global system variable to the
<code class="filename">
mysqld-auto.cnf
</code>
file (and set the
runtime value), use the
<a class="link" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
<code class="literal">
SET
PERSIST
</code>
</a>
statement, which requires the
<a class="link" href="privileges-provided.html#priv_system-variables-admin">
<code class="literal">
SYSTEM_VARIABLES_ADMIN
</code>
</a>
or
<a class="link" href="privileges-provided.html#priv_super">
<code class="literal">
SUPER
</code>
</a>
privilege.
</p>
</li>
<li class="listitem">
<p>
To persist a global system variable to the
<code class="filename">
mysqld-auto.cnf
</code>
file (without setting
the runtime value), use the
<a class="link" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
<code class="literal">
SET
PERSIST_ONLY
</code>
</a>
statement, which requires the
<a class="link" href="privileges-provided.html#priv_system-variables-admin">
<code class="literal">
SYSTEM_VARIABLES_ADMIN
</code>
</a>
and
<a class="link" href="privileges-provided.html#priv_persist-ro-variables-admin">
<code class="literal">
PERSIST_RO_VARIABLES_ADMIN
</code>
</a>
privileges.
<a class="link" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
<code class="literal">
SET
PERSIST_ONLY
</code>
</a>
can be used for both dynamic and
read-only system variables, but is particularly useful for
persisting read-only variables, for which
<a class="link" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
<code class="literal">
SET
PERSIST
</code>
</a>
cannot be used.
</p>
</li>
<li class="listitem">
<p>
Some global system variables are persist-restricted (see
<a class="xref" href="nonpersistible-system-variables.html" title="7.1.9.4 Nonpersistible and Persist-Restricted System Variables">
Section 7.1.9.4, “Nonpersistible and Persist-Restricted System Variables”
</a>
). To
persist these variables, use the
<a class="link" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
<code class="literal">
SET
PERSIST_ONLY
</code>
</a>
statement, which requires the
privileges described previously. In addition, you must
connect to the server using an encrypted connection and
supply an SSL certificate with the Subject value specified
by the
<a class="link" href="server-system-variables.html#sysvar_persist_only_admin_x509_subject">
<code class="literal">
persist_only_admin_x509_subject
</code>
</a>
system variable.
</p>
</li>
</ul>
</div>
<p>
To remove a persisted global system variable from the
<code class="filename">
mysqld-auto.cnf
</code>
file, use the
<a class="link" href="reset-persist.html" title="15.7.8.7 RESET PERSIST Statement">
<code class="literal">
RESET PERSIST
</code>
</a>
statement. These
privileges apply:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
For dynamic system variables,
<a class="link" href="reset-persist.html" title="15.7.8.7 RESET PERSIST Statement">
<code class="literal">
RESET
PERSIST
</code>
</a>
requires the
<a class="link" href="privileges-provided.html#priv_system-variables-admin">
<code class="literal">
SYSTEM_VARIABLES_ADMIN
</code>
</a>
or
<a class="link" href="privileges-provided.html#priv_super">
<code class="literal">
SUPER
</code>
</a>
privilege.
</p>
</li>
<li class="listitem">
<p>
For read-only system variables,
<a class="link" href="reset-persist.html" title="15.7.8.7 RESET PERSIST Statement">
<code class="literal">
RESET
PERSIST
</code>
</a>
requires the
<a class="link" href="privileges-provided.html#priv_system-variables-admin">
<code class="literal">
SYSTEM_VARIABLES_ADMIN
</code>
</a>
and
<a class="link" href="privileges-provided.html#priv_persist-ro-variables-admin">
<code class="literal">
PERSIST_RO_VARIABLES_ADMIN
</code>
</a>
privileges.
</p>
</li>
<li class="listitem">
<p>
For persist-restricted variables,
<a class="link" href="reset-persist.html" title="15.7.8.7 RESET PERSIST Statement">
<code class="literal">
RESET
PERSIST
</code>
</a>
does not require an encrypted connection
to the server made using a particular SSL certificate.
</p>
</li>
</ul>
</div>
<p>
If a global system variable has any exceptions to the preceding
privilege requirements, the variable description indicates those
exceptions. Examples include
<a class="link" href="server-system-variables.html#sysvar_default_table_encryption">
<code class="literal">
default_table_encryption
</code>
</a>
and
<a class="link" href="server-system-variables.html#sysvar_mandatory_roles">
<code class="literal">
mandatory_roles
</code>
</a>
, which require
additional privileges. These additional privileges apply to
operations that set the global runtime value, but not operations
that persist the value.
</p>
<p>
To set a session system variable runtime value, use the
<a class="link" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
<code class="literal">
SET
SESSION
</code>
</a>
statement. In contrast to setting global
runtime values, setting session runtime values normally requires
no special privileges and can be done by any user to affect the
current session. For some system variables, setting the session
value may have effects outside the current session and thus is a
restricted operation that can be done only by users who have a
special privilege:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
The privilege required is
<a class="link" href="privileges-provided.html#priv_session-variables-admin">
<code class="literal">
SESSION_VARIABLES_ADMIN
</code>
</a>
.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
Any user who has
<a class="link" href="privileges-provided.html#priv_system-variables-admin">
<code class="literal">
SYSTEM_VARIABLES_ADMIN
</code>
</a>
or
<a class="link" href="privileges-provided.html#priv_super">
<code class="literal">
SUPER
</code>
</a>
effectively has
<a class="link" href="privileges-provided.html#priv_session-variables-admin">
<code class="literal">
SESSION_VARIABLES_ADMIN
</code>
</a>
by
implication and need not be granted
<a class="link" href="privileges-provided.html#priv_session-variables-admin">
<code class="literal">
SESSION_VARIABLES_ADMIN
</code>
</a>
explicitly.
</p>
</div>
</li>
</ul>
</div>
<p>
If a session system variable is restricted, the variable
description indicates that restriction. Examples include
<a class="link" href="replication-options-binary-log.html#sysvar_binlog_format">
<code class="literal">
binlog_format
</code>
</a>
and
<a class="link" href="replication-options-binary-log.html#sysvar_sql_log_bin">
<code class="literal">
sql_log_bin
</code>
</a>
. Setting the
session value of these variables affects binary logging for the
current session, but may also have wider implications for the
integrity of server replication and backups.
</p>
<p>
<a class="link" href="privileges-provided.html#priv_session-variables-admin">
<code class="literal">
SESSION_VARIABLES_ADMIN
</code>
</a>
enables
administrators to minimize the privilege footprint of users who
may previously have been granted
<a class="link" href="privileges-provided.html#priv_system-variables-admin">
<code class="literal">
SYSTEM_VARIABLES_ADMIN
</code>
</a>
or
<a class="link" href="privileges-provided.html#priv_super">
<code class="literal">
SUPER
</code>
</a>
for the purpose of enabling
them to modify restricted session system variables. Suppose that
an administrator has created the following role to confer the
ability to set restricted session system variables:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa56712652"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">ROLE</span> set_session_sysvars<span class="token punctuation">;</span>
<span class="token keyword">GRANT</span> SYSTEM_VARIABLES_ADMIN <span class="token keyword">ON</span> <span class="token operator">*</span><span class="token punctuation">.</span><span class="token operator">*</span> <span class="token keyword">TO</span> set_session_sysvars<span class="token punctuation">;</span></code></pre>
</div>
<p>
Any user granted the
<code class="literal">
set_session_sysvars
</code>
role
(and who has that role active) is able to set restricted session
system variables. However, that user is also able to set global
system variables, which may be undesirable.
</p>
<p>
By modifying the role to have
<a class="link" href="privileges-provided.html#priv_session-variables-admin">
<code class="literal">
SESSION_VARIABLES_ADMIN
</code>
</a>
instead
of
<a class="link" href="privileges-provided.html#priv_system-variables-admin">
<code class="literal">
SYSTEM_VARIABLES_ADMIN
</code>
</a>
, the
role privileges can be reduced to the ability to set restricted
session system variables and nothing else. To modify the role,
use these statements:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa76425217"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">GRANT</span> SESSION_VARIABLES_ADMIN <span class="token keyword">ON</span> <span class="token operator">*</span><span class="token punctuation">.</span><span class="token operator">*</span> <span class="token keyword">TO</span> set_session_sysvars<span class="token punctuation">;</span>
<span class="token keyword">REVOKE</span> SYSTEM_VARIABLES_ADMIN <span class="token keyword">ON</span> <span class="token operator">*</span><span class="token punctuation">.</span><span class="token operator">*</span> <span class="token keyword">FROM</span> set_session_sysvars<span class="token punctuation">;</span></code></pre>
</div>
<p>
Modifying the role has an immediate effect: Any account granted
the
<code class="literal">
set_session_sysvars
</code>
role no longer has
<a class="link" href="privileges-provided.html#priv_system-variables-admin">
<code class="literal">
SYSTEM_VARIABLES_ADMIN
</code>
</a>
and is not
able to set global system variables without being granted that
ability explicitly. A similar
<a class="link" href="grant.html" title="15.7.1.6 GRANT Statement">
<code class="literal">
GRANT
</code>
</a>
/
<a class="link" href="revoke.html" title="15.7.1.8 REVOKE Statement">
<code class="literal">
REVOKE
</code>
</a>
sequence can be applied to any account that was granted
<a class="link" href="privileges-provided.html#priv_system-variables-admin">
<code class="literal">
SYSTEM_VARIABLES_ADMIN
</code>
</a>
directly
rather than by means of a role.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/innodb-performance-midpoint_insertion.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="innodb-performance-midpoint_insertion">
</a>
17.8.3.3 Making the Buffer Pool Scan Resistant
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045163150272">
</a>
<a class="indexterm" name="idm46045163149200">
</a>
<a class="indexterm" name="idm46045163148128">
</a>
<a class="indexterm" name="idm46045163147056">
</a>
<a class="indexterm" name="idm46045163145984">
</a>
<a class="indexterm" name="idm46045163144912">
</a>
<a class="indexterm" name="idm46045163143840">
</a>
<p>
Rather than using a strict
<a class="link" href="glossary.html#glos_lru" title="LRU">
LRU
</a>
algorithm,
<code class="literal">
InnoDB
</code>
uses a technique to
minimize the amount of data that is brought into the
<a class="link" href="glossary.html#glos_buffer_pool" title="buffer pool">
buffer pool
</a>
and never
accessed again. The goal is to make sure that frequently
accessed (
<span class="quote">
“
<span class="quote">
hot
</span>
”
</span>
) pages remain in the buffer pool,
even as
<a class="link" href="glossary.html#glos_read_ahead" title="read-ahead">
read-ahead
</a>
and
<a class="link" href="glossary.html#glos_full_table_scan" title="full table scan">
full table scans
</a>
bring in new blocks that might or might not be accessed
afterward.
</p>
<p>
Newly read blocks are inserted into the middle of the LRU list.
All newly read pages are inserted at a location that by default
is
<code class="literal">
3/8
</code>
from the tail of the LRU list. The
pages are moved to the front of the list (the most-recently used
end) when they are accessed in the buffer pool for the first
time. Thus, pages that are never accessed never make it to the
front portion of the LRU list, and
<span class="quote">
“
<span class="quote">
age out
</span>
”
</span>
sooner
than with a strict LRU approach. This arrangement divides the
LRU list into two segments, where the pages downstream of the
insertion point are considered
<span class="quote">
“
<span class="quote">
old
</span>
”
</span>
and are
desirable victims for LRU eviction.
</p>
<p>
For an explanation of the inner workings of the
<code class="literal">
InnoDB
</code>
buffer pool and specifics about the
LRU algorithm, see
<a class="xref" href="innodb-buffer-pool.html" title="17.5.1 Buffer Pool">
Section 17.5.1, “Buffer Pool”
</a>
.
</p>
<p>
You can control the insertion point in the LRU list and choose
whether
<code class="literal">
InnoDB
</code>
applies the same optimization
to blocks brought into the buffer pool by table or index scans.
The configuration parameter
<a class="link" href="innodb-parameters.html#sysvar_innodb_old_blocks_pct">
<code class="literal">
innodb_old_blocks_pct
</code>
</a>
controls
the percentage of
<span class="quote">
“
<span class="quote">
old
</span>
”
</span>
blocks in the LRU list. The
default value of
<a class="link" href="innodb-parameters.html#sysvar_innodb_old_blocks_pct">
<code class="literal">
innodb_old_blocks_pct
</code>
</a>
is
<code class="literal">
37
</code>
, corresponding to the original fixed ratio
of 3/8. The value range is
<code class="literal">
5
</code>
(new pages in
the buffer pool age out very quickly) to
<code class="literal">
95
</code>
(only 5% of the buffer pool is reserved for hot pages, making
the algorithm close to the familiar LRU strategy).
</p>
<p>
The optimization that keeps the buffer pool from being churned
by read-ahead can avoid similar problems due to table or index
scans. In these scans, a data page is typically accessed a few
times in quick succession and is never touched again. The
configuration parameter
<a class="link" href="innodb-parameters.html#sysvar_innodb_old_blocks_time">
<code class="literal">
innodb_old_blocks_time
</code>
</a>
specifies the time window (in milliseconds) after the first
access to a page during which it can be accessed without being
moved to the front (most-recently used end) of the LRU list. The
default value of
<a class="link" href="innodb-parameters.html#sysvar_innodb_old_blocks_time">
<code class="literal">
innodb_old_blocks_time
</code>
</a>
is
<code class="literal">
1000
</code>
. Increasing this value makes more and
more blocks likely to age out faster from the buffer pool.
</p>
<p>
Both
<a class="link" href="innodb-parameters.html#sysvar_innodb_old_blocks_pct">
<code class="literal">
innodb_old_blocks_pct
</code>
</a>
and
<a class="link" href="innodb-parameters.html#sysvar_innodb_old_blocks_time">
<code class="literal">
innodb_old_blocks_time
</code>
</a>
can be
specified in the MySQL option file (
<code class="literal">
my.cnf
</code>
or
<code class="literal">
my.ini
</code>
) or changed at runtime with the
<a class="link" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
<code class="literal">
SET
GLOBAL
</code>
</a>
statement. Changing the value at runtime
requires privileges sufficient to set global system variables.
See
<a class="xref" href="system-variable-privileges.html" title="7.1.9.1 System Variable Privileges">
Section 7.1.9.1, “System Variable Privileges”
</a>
.
</p>
<p>
To help you gauge the effect of setting these parameters, the
<code class="literal">
SHOW ENGINE INNODB STATUS
</code>
statement reports
buffer pool statistics. For details, see
<a class="xref" href="innodb-buffer-pool.html#innodb-buffer-pool-monitoring" title="Monitoring the Buffer Pool Using the InnoDB Standard Monitor">
Monitoring the Buffer Pool Using the InnoDB Standard Monitor
</a>
.
</p>
<p>
Because the effects of these parameters can vary widely based on
your hardware configuration, your data, and the details of your
workload, always benchmark to verify the effectiveness before
changing these settings in any performance-critical or
production environment.
</p>
<p>
In mixed workloads where most of the activity is OLTP type with
periodic batch reporting queries which result in large scans,
setting the value of
<a class="link" href="innodb-parameters.html#sysvar_innodb_old_blocks_time">
<code class="literal">
innodb_old_blocks_time
</code>
</a>
during
the batch runs can help keep the working set of the normal
workload in the buffer pool.
</p>
<p>
When scanning large tables that cannot fit entirely in the
buffer pool, setting
<a class="link" href="innodb-parameters.html#sysvar_innodb_old_blocks_pct">
<code class="literal">
innodb_old_blocks_pct
</code>
</a>
to a
small value keeps the data that is only read once from consuming
a significant portion of the buffer pool. For example, setting
<code class="literal">
innodb_old_blocks_pct=5
</code>
restricts this data
that is only read once to 5% of the buffer pool.
</p>
<p>
When scanning small tables that do fit into memory, there is
less overhead for moving pages around within the buffer pool, so
you can leave
<a class="link" href="innodb-parameters.html#sysvar_innodb_old_blocks_pct">
<code class="literal">
innodb_old_blocks_pct
</code>
</a>
at its
default value, or even higher, such as
<code class="literal">
innodb_old_blocks_pct=50
</code>
.
</p>
<p>
The effect of the
<a class="link" href="innodb-parameters.html#sysvar_innodb_old_blocks_time">
<code class="literal">
innodb_old_blocks_time
</code>
</a>
parameter is harder to predict than the
<a class="link" href="innodb-parameters.html#sysvar_innodb_old_blocks_pct">
<code class="literal">
innodb_old_blocks_pct
</code>
</a>
parameter, is relatively small, and varies more with the
workload. To arrive at an optimal value, conduct your own
benchmarks if the performance improvement from adjusting
<a class="link" href="innodb-parameters.html#sysvar_innodb_old_blocks_pct">
<code class="literal">
innodb_old_blocks_pct
</code>
</a>
is not
sufficient.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/windows-and-ssh.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="windows-and-ssh">
</a>
8.3.4 Connecting to MySQL Remotely from Windows with SSH
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045246499456">
</a>
<a class="indexterm" name="idm46045246498448">
</a>
<a class="indexterm" name="idm46045246496960">
</a>
<p>
This section describes how to get an encrypted connection to a
remote MySQL server with SSH. The information was provided by
David Carlson
<code class="email">
<
<a class="email" href="mailto:[email protected]">
[email protected]
</a>
>
</code>
.
</p>
<div class="orderedlist">
<ol class="orderedlist" type="1">
<li class="listitem">
<p>
Install an SSH client on your Windows machine. For a
comparison of SSH clients, see
<a class="ulink" href="http://en.wikipedia.org/wiki/Comparison_of_SSH_clients" target="_blank">
http://en.wikipedia.org/wiki/Comparison_of_SSH_clients
</a>
.
</p>
</li>
<li class="listitem">
<p>
Start your Windows SSH client. Set
<code class="literal">
Host_Name =
<em class="replaceable">
<code>
yourmysqlserver_URL_or_IP
</code>
</em>
</code>
.
Set
<code class="literal">
userid=
<em class="replaceable">
<code>
your_userid
</code>
</em>
</code>
to log in to your server. This
<code class="literal">
userid
</code>
value
might not be the same as the user name of your MySQL account.
</p>
</li>
<li class="listitem">
<p>
Set up port forwarding. Either do a remote forward (Set
<code class="literal">
local_port: 3306
</code>
,
<code class="literal">
remote_host:
<em class="replaceable">
<code>
yourmysqlservername_or_ip
</code>
</em>
</code>
,
<code class="literal">
remote_port: 3306
</code>
) or a local forward (Set
<code class="literal">
port: 3306
</code>
,
<code class="literal">
host:
localhost
</code>
,
<code class="literal">
remote port: 3306
</code>
).
</p>
</li>
<li class="listitem">
<p>
Save everything, otherwise you must redo it the next time.
</p>
</li>
<li class="listitem">
<p>
Log in to your server with the SSH session you just created.
</p>
</li>
<li class="listitem">
<p>
On your Windows machine, start some ODBC application (such as
Access).
</p>
</li>
<li class="listitem">
<p>
Create a new file in Windows and link to MySQL using the ODBC
driver the same way you normally do, except type in
<code class="literal">
localhost
</code>
for the MySQL host server, not
<em class="replaceable">
<code>
yourmysqlservername
</code>
</em>
.
</p>
</li>
</ol>
</div>
<p>
At this point, you should have an ODBC connection to MySQL,
encrypted using SSH.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/general-information-schema-tables.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h2 class="title">
<a name="general-information-schema-tables">
</a>
28.3 INFORMATION_SCHEMA General Tables
</h2>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="information-schema-general-table-reference.html">
28.3.1 INFORMATION_SCHEMA General Table Reference
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-administrable-role-authorizations-table.html">
28.3.2 The INFORMATION_SCHEMA ADMINISTRABLE_ROLE_AUTHORIZATIONS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-applicable-roles-table.html">
28.3.3 The INFORMATION_SCHEMA APPLICABLE_ROLES Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-character-sets-table.html">
28.3.4 The INFORMATION_SCHEMA CHARACTER_SETS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-check-constraints-table.html">
28.3.5 The INFORMATION_SCHEMA CHECK_CONSTRAINTS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-collations-table.html">
28.3.6 The INFORMATION_SCHEMA COLLATIONS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-collation-character-set-applicability-table.html">
28.3.7 The INFORMATION_SCHEMA COLLATION_CHARACTER_SET_APPLICABILITY Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-columns-table.html">
28.3.8 The INFORMATION_SCHEMA COLUMNS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-columns-extensions-table.html">
28.3.9 The INFORMATION_SCHEMA COLUMNS_EXTENSIONS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-column-privileges-table.html">
28.3.10 The INFORMATION_SCHEMA COLUMN_PRIVILEGES Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-column-statistics-table.html">
28.3.11 The INFORMATION_SCHEMA COLUMN_STATISTICS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-enabled-roles-table.html">
28.3.12 The INFORMATION_SCHEMA ENABLED_ROLES Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-engines-table.html">
28.3.13 The INFORMATION_SCHEMA ENGINES Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-events-table.html">
28.3.14 The INFORMATION_SCHEMA EVENTS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-files-table.html">
28.3.15 The INFORMATION_SCHEMA FILES Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-key-column-usage-table.html">
28.3.16 The INFORMATION_SCHEMA KEY_COLUMN_USAGE Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-keywords-table.html">
28.3.17 The INFORMATION_SCHEMA KEYWORDS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-ndb-transid-mysql-connection-map-table.html">
28.3.18 The INFORMATION_SCHEMA ndb_transid_mysql_connection_map Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-optimizer-trace-table.html">
28.3.19 The INFORMATION_SCHEMA OPTIMIZER_TRACE Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-parameters-table.html">
28.3.20 The INFORMATION_SCHEMA PARAMETERS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-partitions-table.html">
28.3.21 The INFORMATION_SCHEMA PARTITIONS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-plugins-table.html">
28.3.22 The INFORMATION_SCHEMA PLUGINS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-processlist-table.html">
28.3.23 The INFORMATION_SCHEMA PROCESSLIST Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-profiling-table.html">
28.3.24 The INFORMATION_SCHEMA PROFILING Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-referential-constraints-table.html">
28.3.25 The INFORMATION_SCHEMA REFERENTIAL_CONSTRAINTS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-resource-groups-table.html">
28.3.26 The INFORMATION_SCHEMA RESOURCE_GROUPS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-role-column-grants-table.html">
28.3.27 The INFORMATION_SCHEMA ROLE_COLUMN_GRANTS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-role-routine-grants-table.html">
28.3.28 The INFORMATION_SCHEMA ROLE_ROUTINE_GRANTS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-role-table-grants-table.html">
28.3.29 The INFORMATION_SCHEMA ROLE_TABLE_GRANTS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-routines-table.html">
28.3.30 The INFORMATION_SCHEMA ROUTINES Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-schemata-table.html">
28.3.31 The INFORMATION_SCHEMA SCHEMATA Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-schemata-extensions-table.html">
28.3.32 The INFORMATION_SCHEMA SCHEMATA_EXTENSIONS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-schema-privileges-table.html">
28.3.33 The INFORMATION_SCHEMA SCHEMA_PRIVILEGES Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-statistics-table.html">
28.3.34 The INFORMATION_SCHEMA STATISTICS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-st-geometry-columns-table.html">
28.3.35 The INFORMATION_SCHEMA ST_GEOMETRY_COLUMNS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-st-spatial-reference-systems-table.html">
28.3.36 The INFORMATION_SCHEMA ST_SPATIAL_REFERENCE_SYSTEMS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-st-units-of-measure-table.html">
28.3.37 The INFORMATION_SCHEMA ST_UNITS_OF_MEASURE Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-tables-table.html">
28.3.38 The INFORMATION_SCHEMA TABLES Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-tables-extensions-table.html">
28.3.39 The INFORMATION_SCHEMA TABLES_EXTENSIONS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-tablespaces-extensions-table.html">
28.3.40 The INFORMATION_SCHEMA TABLESPACES_EXTENSIONS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-table-constraints-table.html">
28.3.41 The INFORMATION_SCHEMA TABLE_CONSTRAINTS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-table-constraints-extensions-table.html">
28.3.42 The INFORMATION_SCHEMA TABLE_CONSTRAINTS_EXTENSIONS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-table-privileges-table.html">
28.3.43 The INFORMATION_SCHEMA TABLE_PRIVILEGES Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-triggers-table.html">
28.3.44 The INFORMATION_SCHEMA TRIGGERS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-user-attributes-table.html">
28.3.45 The INFORMATION_SCHEMA USER_ATTRIBUTES Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-user-privileges-table.html">
28.3.46 The INFORMATION_SCHEMA USER_PRIVILEGES Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-views-table.html">
28.3.47 The INFORMATION_SCHEMA VIEWS Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-view-routine-usage-table.html">
28.3.48 The INFORMATION_SCHEMA VIEW_ROUTINE_USAGE Table
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="information-schema-view-table-usage-table.html">
28.3.49 The INFORMATION_SCHEMA VIEW_TABLE_USAGE Table
</a>
</span>
</dt>
</dl>
</div>
<a class="indexterm" name="idm46045080551584">
</a>
<p>
The following sections describe what may be denoted as the
<span class="quote">
“
<span class="quote">
general
</span>
”
</span>
set of
<code class="literal">
INFORMATION_SCHEMA
</code>
tables. These are the tables not associated with particular storage
engines, components, or plugins.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/json-attribute-functions.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="json-attribute-functions">
</a>
14.17.5 Functions That Return JSON Value Attributes
</h3>
</div>
</div>
</div>
<p>
The functions in this section return attributes of JSON values.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<a name="function_json-depth">
</a>
<p>
<a class="link" href="json-attribute-functions.html#function_json-depth">
<code class="literal">
JSON_DEPTH(
<em class="replaceable">
<code>
json_doc
</code>
</em>
)
</code>
</a>
</p>
<a class="indexterm" name="idm46045194794192">
</a>
<p>
Returns the maximum depth of a JSON document. Returns
<code class="literal">
NULL
</code>
if the argument is
<code class="literal">
NULL
</code>
. An error occurs if the argument is
not a valid JSON document.
</p>
<p>
An empty array, empty object, or scalar value has depth 1. A
nonempty array containing only elements of depth 1 or nonempty
object containing only member values of depth 1 has depth 2.
Otherwise, a JSON document has depth greater than 2.
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa17447352"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token function">JSON_DEPTH</span><span class="token punctuation">(</span><span class="token string">'{}'</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token function">JSON_DEPTH</span><span class="token punctuation">(</span><span class="token string">'[]'</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token function">JSON_DEPTH</span><span class="token punctuation">(</span><span class="token string">'true'</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> JSON_DEPTH('{}') <span class="token punctuation">|</span> JSON_DEPTH('[]') <span class="token punctuation">|</span> JSON_DEPTH('true') <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 1 <span class="token punctuation">|</span> 1 <span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token function">JSON_DEPTH</span><span class="token punctuation">(</span><span class="token string">'[10, 20]'</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token function">JSON_DEPTH</span><span class="token punctuation">(</span><span class="token string">'[[], {}]'</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> JSON_DEPTH('[10, 20]') <span class="token punctuation">|</span> JSON_DEPTH('[[], {}]') <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 2 <span class="token punctuation">|</span> 2 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token function">JSON_DEPTH</span><span class="token punctuation">(</span><span class="token string">'[10, {"a": 20}]'</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> JSON_DEPTH('[10, {"a": 20}]') <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 3 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
</li>
<li class="listitem">
<a name="function_json-length">
</a>
<p>
<a class="link" href="json-attribute-functions.html#function_json-length">
<code class="literal">
JSON_LENGTH(
<em class="replaceable">
<code>
json_doc
</code>
</em>
[,
<em class="replaceable">
<code>
path
</code>
</em>
])
</code>
</a>
</p>
<a class="indexterm" name="idm46045194778096">
</a>
<p>
Returns the length of a JSON document, or, if a
<em class="replaceable">
<code>
path
</code>
</em>
argument is given, the length
of the value within the document identified by the path.
Returns
<code class="literal">
NULL
</code>
if any argument is
<code class="literal">
NULL
</code>
or the
<em class="replaceable">
<code>
path
</code>
</em>
argument does not identify a value in the document. An error
occurs if the
<em class="replaceable">
<code>
json_doc
</code>
</em>
argument is
not a valid JSON document or the
<em class="replaceable">
<code>
path
</code>
</em>
argument is not a valid path
expression.
</p>
<p>
The length of a document is determined as follows:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
The length of a scalar is 1.
</p>
</li>
<li class="listitem">
<p>
The length of an array is the number of array elements.
</p>
</li>
<li class="listitem">
<p>
The length of an object is the number of object members.
</p>
</li>
<li class="listitem">
<p>
The length does not count the length of nested arrays or
objects.
</p>
</li>
</ul>
</div>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa3923164"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token function">JSON_LENGTH</span><span class="token punctuation">(</span><span class="token string">'[1, 2, {"a": 3}]'</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> JSON_LENGTH('[1, 2, {"a": 3}]') <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 3 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token function">JSON_LENGTH</span><span class="token punctuation">(</span><span class="token string">'{"a": 1, "b": {"c": 30}}'</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> JSON_LENGTH('{"a": 1, "b": {"c": 30}}') <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 2 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token function">JSON_LENGTH</span><span class="token punctuation">(</span><span class="token string">'{"a": 1, "b": {"c": 30}}'</span><span class="token punctuation">,</span> <span class="token string">'$.b'</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> JSON_LENGTH('{"a": 1, "b": {"c": 30}}', '$.b') <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
</li>
<li class="listitem">
<a name="function_json-type">
</a>
<p>
<a class="link" href="json-attribute-functions.html#function_json-type">
<code class="literal">
JSON_TYPE(
<em class="replaceable">
<code>
json_val
</code>
</em>
)
</code>
</a>
</p>
<a class="indexterm" name="idm46045194757040">
</a>
<p>
Returns a
<code class="literal">
utf8mb4
</code>
string indicating the
type of a JSON value. This can be an object, an array, or a
scalar type, as shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa51190313"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SET</span> <span class="token variable">@j</span> <span class="token operator">=</span> <span class="token string">'{"a": [10, true]}'</span><span class="token punctuation">;</span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token function">JSON_TYPE</span><span class="token punctuation">(</span><span class="token variable">@j</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> JSON_TYPE(@j) <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> OBJECT <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token function">JSON_TYPE</span><span class="token punctuation">(</span><span class="token function">JSON_EXTRACT</span><span class="token punctuation">(</span><span class="token variable">@j</span><span class="token punctuation">,</span> <span class="token string">'$.a'</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> JSON_TYPE(JSON_EXTRACT(@j, '$.a')) <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> ARRAY <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token function">JSON_TYPE</span><span class="token punctuation">(</span><span class="token function">JSON_EXTRACT</span><span class="token punctuation">(</span><span class="token variable">@j</span><span class="token punctuation">,</span> <span class="token string">'$.a[0]'</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> JSON_TYPE(JSON_EXTRACT(@j, '$.a[0]')) <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> INTEGER <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token function">JSON_TYPE</span><span class="token punctuation">(</span><span class="token function">JSON_EXTRACT</span><span class="token punctuation">(</span><span class="token variable">@j</span><span class="token punctuation">,</span> <span class="token string">'$.a[1]'</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> JSON_TYPE(JSON_EXTRACT(@j, '$.a[1]')) <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> BOOLEAN <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
<p>
<a class="link" href="json-attribute-functions.html#function_json-type">
<code class="literal">
JSON_TYPE()
</code>
</a>
returns
<code class="literal">
NULL
</code>
if the argument is
<code class="literal">
NULL
</code>
:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa94056040"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token function">JSON_TYPE</span><span class="token punctuation">(</span><span class="token boolean">NULL</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> JSON_TYPE(NULL) <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> NULL <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
<p>
An error occurs if the argument is not a valid JSON value:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa90883227"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token function">JSON_TYPE</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output">ERROR 3146 (22032)<span class="token punctuation">:</span> Invalid data type for JSON data in argument 1
to function json_type; a JSON string or JSON type is required.</span></code></pre>
</div>
<p>
For a non-
<code class="literal">
NULL
</code>
, non-error result, the
following list describes the possible
<a class="link" href="json-attribute-functions.html#function_json-type">
<code class="literal">
JSON_TYPE()
</code>
</a>
return values:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
Purely JSON types:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: square; ">
<li class="listitem">
<p>
<code class="literal">
OBJECT
</code>
: JSON objects
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
ARRAY
</code>
: JSON arrays
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
BOOLEAN
</code>
: The JSON true and false
literals
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
NULL
</code>
: The JSON null literal
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
Numeric types:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: square; ">
<li class="listitem">
<p>
<code class="literal">
INTEGER
</code>
: MySQL
<a class="link" href="integer-types.html" title="13.1.2 Integer Types (Exact Value) - INTEGER, INT, SMALLINT, TINYINT, MEDIUMINT, BIGINT">
<code class="literal">
TINYINT
</code>
</a>
,
<a class="link" href="integer-types.html" title="13.1.2 Integer Types (Exact Value) - INTEGER, INT, SMALLINT, TINYINT, MEDIUMINT, BIGINT">
<code class="literal">
SMALLINT
</code>
</a>
,
<a class="link" href="integer-types.html" title="13.1.2 Integer Types (Exact Value) - INTEGER, INT, SMALLINT, TINYINT, MEDIUMINT, BIGINT">
<code class="literal">
MEDIUMINT
</code>
</a>
and
<a class="link" href="integer-types.html" title="13.1.2 Integer Types (Exact Value) - INTEGER, INT, SMALLINT, TINYINT, MEDIUMINT, BIGINT">
<code class="literal">
INT
</code>
</a>
and
<a class="link" href="integer-types.html" title="13.1.2 Integer Types (Exact Value) - INTEGER, INT, SMALLINT, TINYINT, MEDIUMINT, BIGINT">
<code class="literal">
BIGINT
</code>
</a>
scalars
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
DOUBLE
</code>
: MySQL
<a class="link" href="floating-point-types.html" title="13.1.4 Floating-Point Types (Approximate Value) - FLOAT, DOUBLE">
<code class="literal">
DOUBLE
</code>
</a>
<a class="link" href="floating-point-types.html" title="13.1.4 Floating-Point Types (Approximate Value) - FLOAT, DOUBLE">
<code class="literal">
FLOAT
</code>
</a>
scalars
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
DECIMAL
</code>
: MySQL
<a class="link" href="fixed-point-types.html" title="13.1.3 Fixed-Point Types (Exact Value) - DECIMAL, NUMERIC">
<code class="literal">
DECIMAL
</code>
</a>
and
<a class="link" href="fixed-point-types.html" title="13.1.3 Fixed-Point Types (Exact Value) - DECIMAL, NUMERIC">
<code class="literal">
NUMERIC
</code>
</a>
scalars
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
Temporal types:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: square; ">
<li class="listitem">
<p>
<code class="literal">
DATETIME
</code>
: MySQL
<a class="link" href="datetime.html" title="13.2.2 The DATE, DATETIME, and TIMESTAMP Types">
<code class="literal">
DATETIME
</code>
</a>
and
<a class="link" href="datetime.html" title="13.2.2 The DATE, DATETIME, and TIMESTAMP Types">
<code class="literal">
TIMESTAMP
</code>
</a>
scalars
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
DATE
</code>
: MySQL
<a class="link" href="datetime.html" title="13.2.2 The DATE, DATETIME, and TIMESTAMP Types">
<code class="literal">
DATE
</code>
</a>
scalars
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
TIME
</code>
: MySQL
<a class="link" href="time.html" title="13.2.3 The TIME Type">
<code class="literal">
TIME
</code>
</a>
scalars
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
String types:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: square; ">
<li class="listitem">
<p>
<code class="literal">
STRING
</code>
: MySQL
<code class="literal">
utf8mb3
</code>
character type scalars:
<a class="link" href="char.html" title="13.3.2 The CHAR and VARCHAR Types">
<code class="literal">
CHAR
</code>
</a>
,
<a class="link" href="char.html" title="13.3.2 The CHAR and VARCHAR Types">
<code class="literal">
VARCHAR
</code>
</a>
,
<a class="link" href="blob.html" title="13.3.4 The BLOB and TEXT Types">
<code class="literal">
TEXT
</code>
</a>
,
<a class="link" href="enum.html" title="13.3.5 The ENUM Type">
<code class="literal">
ENUM
</code>
</a>
, and
<a class="link" href="set.html" title="13.3.6 The SET Type">
<code class="literal">
SET
</code>
</a>
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
Binary types:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: square; ">
<li class="listitem">
<p>
<code class="literal">
BLOB
</code>
: MySQL binary type scalars
including
<a class="link" href="binary-varbinary.html" title="13.3.3 The BINARY and VARBINARY Types">
<code class="literal">
BINARY
</code>
</a>
,
<a class="link" href="binary-varbinary.html" title="13.3.3 The BINARY and VARBINARY Types">
<code class="literal">
VARBINARY
</code>
</a>
,
<a class="link" href="blob.html" title="13.3.4 The BLOB and TEXT Types">
<code class="literal">
BLOB
</code>
</a>
, and
<a class="link" href="bit-type.html" title="13.1.5 Bit-Value Type - BIT">
<code class="literal">
BIT
</code>
</a>
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
All other types:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: square; ">
<li class="listitem">
<p>
<code class="literal">
OPAQUE
</code>
(raw bits)
</p>
</li>
</ul>
</div>
</li>
</ul>
</div>
</li>
<li class="listitem">
<a name="function_json-valid">
</a>
<p>
<a class="link" href="json-attribute-functions.html#function_json-valid">
<code class="literal">
JSON_VALID(
<em class="replaceable">
<code>
val
</code>
</em>
)
</code>
</a>
</p>
<a class="indexterm" name="idm46045194677184">
</a>
<p>
Returns 0 or 1 to indicate whether a value is valid JSON.
Returns
<code class="literal">
NULL
</code>
if the argument is
<code class="literal">
NULL
</code>
.
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa31115537"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token function">JSON_VALID</span><span class="token punctuation">(</span><span class="token string">'{"a": 1}'</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> JSON_VALID('{"a": 1}') <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token function">JSON_VALID</span><span class="token punctuation">(</span><span class="token string">'hello'</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token function">JSON_VALID</span><span class="token punctuation">(</span><span class="token string">'"hello"'</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> JSON_VALID('hello') <span class="token punctuation">|</span> JSON_VALID('"hello"') <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 0 <span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/floating-point-types.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="floating-point-types">
</a>
13.1.4 Floating-Point Types (Approximate Value) - FLOAT, DOUBLE
</h3>
</div>
</div>
</div>
<p>
The
<code class="literal">
FLOAT
</code>
and
<code class="literal">
DOUBLE
</code>
types
represent approximate numeric data values. MySQL uses four bytes
for single-precision values and eight bytes for double-precision
values.
</p>
<p>
For
<code class="literal">
FLOAT
</code>
, the SQL standard permits an
optional specification of the precision (but not the range of
the exponent) in bits following the keyword
<code class="literal">
FLOAT
</code>
in parentheses, that is,
<a class="link" href="floating-point-types.html" title="13.1.4 Floating-Point Types (Approximate Value) - FLOAT, DOUBLE">
<code class="literal">
FLOAT(
<em class="replaceable">
<code>
p
</code>
</em>
)
</code>
</a>
.
MySQL also supports this optional precision specification, but
the precision value in
<a class="link" href="floating-point-types.html" title="13.1.4 Floating-Point Types (Approximate Value) - FLOAT, DOUBLE">
<code class="literal">
FLOAT(
<em class="replaceable">
<code>
p
</code>
</em>
)
</code>
</a>
is used only to determine storage size. A precision from 0 to 23
results in a 4-byte single-precision
<code class="literal">
FLOAT
</code>
column. A precision from 24 to 53 results in an 8-byte
double-precision
<code class="literal">
DOUBLE
</code>
column.
</p>
<p>
MySQL permits a nonstandard syntax:
<code class="literal">
FLOAT(
<em class="replaceable">
<code>
M
</code>
</em>
,
<em class="replaceable">
<code>
D
</code>
</em>
)
</code>
or
<code class="literal">
REAL(
<em class="replaceable">
<code>
M
</code>
</em>
,
<em class="replaceable">
<code>
D
</code>
</em>
)
</code>
or
<code class="literal">
DOUBLE
PRECISION(
<em class="replaceable">
<code>
M
</code>
</em>
,
<em class="replaceable">
<code>
D
</code>
</em>
)
</code>
.
Here,
<code class="literal">
(
<em class="replaceable">
<code>
M
</code>
</em>
,
<em class="replaceable">
<code>
D
</code>
</em>
)
</code>
means than values can be stored with up to
<em class="replaceable">
<code>
M
</code>
</em>
digits in total, of which
<em class="replaceable">
<code>
D
</code>
</em>
digits may be after the decimal
point. For example, a column defined as
<code class="literal">
FLOAT(7,4)
</code>
is displayed as
<code class="literal">
-999.9999
</code>
. MySQL performs rounding when
storing values, so if you insert
<code class="literal">
999.00009
</code>
into a
<code class="literal">
FLOAT(7,4)
</code>
column, the approximate
result is
<code class="literal">
999.0001
</code>
.
</p>
<p>
<code class="literal">
FLOAT(
<em class="replaceable">
<code>
M
</code>
</em>
,
<em class="replaceable">
<code>
D
</code>
</em>
)
</code>
and
<code class="literal">
DOUBLE(
<em class="replaceable">
<code>
M
</code>
</em>
,
<em class="replaceable">
<code>
D
</code>
</em>
)
</code>
are nonstandard MySQL extensions; and are deprecated. You should
expect support for these variants to be removed in a future
version of MySQL.
</p>
<p>
Because floating-point values are approximate and not stored as
exact values, attempts to treat them as exact in comparisons may
lead to problems. They are also subject to platform or
implementation dependencies. For more information, see
<a class="xref" href="problems-with-float.html" title="B.3.4.8 Problems with Floating-Point Values">
Section B.3.4.8, “Problems with Floating-Point Values”
</a>
.
</p>
<p>
For maximum portability, code requiring storage of approximate
numeric data values should use
<code class="literal">
FLOAT
</code>
or
<code class="literal">
DOUBLE PRECISION
</code>
with no specification of
precision or number of digits.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-ndbinfo-dict-obj-tree.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="mysql-cluster-ndbinfo-dict-obj-tree">
</a>
25.6.17.26 The ndbinfo dict_obj_tree Table
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045089635888">
</a>
<p>
The
<code class="literal">
dict_obj_tree
</code>
table provides a tree-based
view of table information from the
<a class="link" href="mysql-cluster-ndbinfo-dict-obj-info.html" title="25.6.17.25 The ndbinfo dict_obj_info Table">
<code class="literal">
dict_obj_info
</code>
</a>
table. This is
intended primarily for use in testing, but can be useful in
visualizing hierarchies of
<code class="literal">
NDB
</code>
database
objects.
</p>
<p>
The
<code class="literal">
dict_obj_tree
</code>
table contains the
following columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
type
</code>
</p>
<p>
Type of
<a class="ulink" href="/doc/ndb-internals/en/ndb-internals-kernel-blocks-dbdict.html" target="_top">
<code class="literal">
DICT
</code>
</a>
object;
join on
<a class="link" href="mysql-cluster-ndbinfo-dict-obj-types.html" title="25.6.17.27 The ndbinfo dict_obj_types Table">
<code class="literal">
dict_obj_types
</code>
</a>
to
obtain the name of the object type
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
id
</code>
</p>
<p>
Object identifier; same as the
<code class="literal">
id
</code>
column
in
<a class="link" href="mysql-cluster-ndbinfo-dict-obj-info.html" title="25.6.17.25 The ndbinfo dict_obj_info Table">
<code class="literal">
dict_obj_info
</code>
</a>
</p>
<p>
For Disk Data undo log files and data files, this is the
same as the value shown in the
<code class="literal">
LOGFILE_GROUP_NUMBER
</code>
column of the
Information Schema
<a class="link" href="information-schema-files-table.html" title="28.3.15 The INFORMATION_SCHEMA FILES Table">
<code class="literal">
FILES
</code>
</a>
table;
for undo log files, it also the same as the value shown for
the
<code class="literal">
log_id
</code>
column in the ndbinfo
<a class="link" href="mysql-cluster-ndbinfo-logbuffers.html" title="25.6.17.43 The ndbinfo logbuffers Table">
<code class="literal">
logbuffers
</code>
</a>
and
<a class="link" href="mysql-cluster-ndbinfo-logspaces.html" title="25.6.17.44 The ndbinfo logspaces Table">
<code class="literal">
logspaces
</code>
</a>
tables
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
name
</code>
</p>
<p>
The fully qualified name of the object; the same as the
<code class="literal">
fq_name
</code>
column in
<a class="link" href="mysql-cluster-ndbinfo-dict-obj-info.html" title="25.6.17.25 The ndbinfo dict_obj_info Table">
<code class="literal">
dict_obj_info
</code>
</a>
</p>
<p>
For a table, this is
<code class="literal">
<em class="replaceable">
<code>
database_name
</code>
</em>
/def/
<em class="replaceable">
<code>
table_name
</code>
</em>
</code>
(the same as its
<em class="replaceable">
<code>
parent_name
</code>
</em>
);
for an index of any type, this takes the form
<code class="literal">
NDB$INDEX_
<em class="replaceable">
<code>
index_id
</code>
</em>
_CUSTOM
</code>
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
parent_type
</code>
</p>
<p>
The
<em class="replaceable">
<code>
DICT
</code>
</em>
object type of this
object's parent object; join on
<a class="link" href="mysql-cluster-ndbinfo-dict-obj-types.html" title="25.6.17.27 The ndbinfo dict_obj_types Table">
<code class="literal">
dict_obj_types
</code>
</a>
to obtain
the name of the object type
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
parent_id
</code>
</p>
<p>
Identifier for this object's parent object; the same as
the
<a class="link" href="mysql-cluster-ndbinfo-dict-obj-info.html" title="25.6.17.25 The ndbinfo dict_obj_info Table">
<code class="literal">
dict_obj_info
</code>
</a>
table's
<code class="literal">
id
</code>
column
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
parent_name
</code>
</p>
<p>
Fully qualified name of this object's parent object;
the same as the
<a class="link" href="mysql-cluster-ndbinfo-dict-obj-info.html" title="25.6.17.25 The ndbinfo dict_obj_info Table">
<code class="literal">
dict_obj_info
</code>
</a>
table's
<code class="literal">
fq_name
</code>
column
</p>
<p>
For a table, this has the form
<code class="literal">
<em class="replaceable">
<code>
database_name
</code>
</em>
/def/
<em class="replaceable">
<code>
table_name
</code>
</em>
</code>
.
For an index, the name is
<code class="literal">
sys/def/
<em class="replaceable">
<code>
table_id
</code>
</em>
/
<em class="replaceable">
<code>
index_name
</code>
</em>
</code>
.
For a primary key, it is
<code class="literal">
sys/def/
<em class="replaceable">
<code>
table_id
</code>
</em>
/PRIMARY
</code>
,
and for a unique key it is
<code class="literal">
sys/def/
<em class="replaceable">
<code>
table_id
</code>
</em>
/
<em class="replaceable">
<code>
uk_name
</code>
</em>
$unique
</code>
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
root_type
</code>
</p>
<p>
The
<em class="replaceable">
<code>
DICT
</code>
</em>
object type of the root
object; join on
<a class="link" href="mysql-cluster-ndbinfo-dict-obj-types.html" title="25.6.17.27 The ndbinfo dict_obj_types Table">
<code class="literal">
dict_obj_types
</code>
</a>
to obtain
the name of the object type
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
root_id
</code>
</p>
<p>
Identifier for the root object; the same as the
<a class="link" href="mysql-cluster-ndbinfo-dict-obj-info.html" title="25.6.17.25 The ndbinfo dict_obj_info Table">
<code class="literal">
dict_obj_info
</code>
</a>
table's
<code class="literal">
id
</code>
column
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
root_name
</code>
</p>
<p>
Fully qualified name of the root object; the same as the
<a class="link" href="mysql-cluster-ndbinfo-dict-obj-info.html" title="25.6.17.25 The ndbinfo dict_obj_info Table">
<code class="literal">
dict_obj_info
</code>
</a>
table's
<code class="literal">
fq_name
</code>
column
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
level
</code>
</p>
<p>
Level of the object in the hierarchy
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
path
</code>
</p>
<p>
Complete path to the object in the
<em class="replaceable">
<code>
NDB
</code>
</em>
object hierarchy; objects are
separated by a right arrow (represented as
<code class="literal">
->
</code>
), starting with the root object on
the left
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
indented_name
</code>
</p>
<p>
The
<code class="literal">
name
</code>
prefixed with a right arrow
(represented as
<code class="literal">
->
</code>
) with a number of
spaces preceding it that correspond to the object's
depth in the hierarchy
</p>
</li>
</ul>
</div>
<p>
The
<code class="literal">
path
</code>
column is useful for obtaining a
complete path to a given
<code class="literal">
NDB
</code>
database object
in a single line, whereas the
<code class="literal">
indented_name
</code>
column can be used to obtain a tree-like layout of complete
hierarchy information for a desired object.
</p>
<p>
<span class="emphasis">
<em>
Example
</em>
</span>
: Assuming the existence of a
<code class="literal">
test
</code>
database and no existing table named
<code class="literal">
t1
</code>
in this database, execute the following
SQL statement:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa85991208"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> test<span class="token punctuation">.</span>t1 <span class="token punctuation">(</span>
a <span class="token datatype">INT</span> <span class="token keyword">PRIMARY</span> <span class="token keyword">KEY</span><span class="token punctuation">,</span>
b <span class="token datatype">INT</span><span class="token punctuation">,</span>
<span class="token keyword">UNIQUE</span> <span class="token keyword">KEY</span><span class="token punctuation">(</span>b<span class="token punctuation">)</span>
<span class="token punctuation">)</span> <span class="token keyword">ENGINE</span> <span class="token operator">=</span> <span class="token keyword">NDB</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
You can obtain the path to the table just created using the
query shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa52802308"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token keyword">path</span> <span class="token keyword">FROM</span> ndbinfo<span class="token punctuation">.</span>dict_obj_tree
<span class="token prompt"> -></span> <span class="token keyword">WHERE</span> <span class="token keyword">name</span> <span class="token operator">LIKE</span> <span class="token string">'test%t1'</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> path <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> test/def/t1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output">1 row in set (0.14 sec)</span></code></pre>
</div>
<p>
You can see the paths to all dependent objects of this table
using the path to the table as the root name in a query like
this one:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa22435575"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token keyword">path</span> <span class="token keyword">FROM</span> ndbinfo<span class="token punctuation">.</span>dict_obj_tree
<span class="token prompt"> -></span> <span class="token keyword">WHERE</span> root_name <span class="token operator">=</span> <span class="token string">'test/def/t1'</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> path <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> test/def/t1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> test/def/t1 <span class="token punctuation">-</span>> sys/def/13/b <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> test/def/t1 <span class="token punctuation">-</span>> sys/def/13/b <span class="token punctuation">-</span>> NDB$INDEX_15_CUSTOM <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> test/def/t1 <span class="token punctuation">-</span>> sys/def/13/b$unique <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> test/def/t1 <span class="token punctuation">-</span>> sys/def/13/b$unique <span class="token punctuation">-</span>> NDB$INDEX_16_UI <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> test/def/t1 <span class="token punctuation">-</span>> sys/def/13/PRIMARY <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> test/def/t1 <span class="token punctuation">-</span>> sys/def/13/PRIMARY <span class="token punctuation">-</span>> NDB$INDEX_14_CUSTOM <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output">7 rows in set (0.16 sec)</span></code></pre>
</div>
<p>
To obtain a hierarchical view of the
<code class="literal">
t1
</code>
table
with all its dependent objects, execute a query similar to this
one which selects the indented name of each object having
<code class="literal">
test/def/t1
</code>
as the name of its root object:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa49404845"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> indented_name <span class="token keyword">FROM</span> ndbinfo<span class="token punctuation">.</span>dict_obj_tree
<span class="token prompt"> -></span> <span class="token keyword">WHERE</span> root_name <span class="token operator">=</span> <span class="token string">'test/def/t1'</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> indented_name <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> test/def/t1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> <span class="token punctuation">-</span>> sys/def/13/b <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> <span class="token punctuation">-</span>> NDB$INDEX_15_CUSTOM <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> <span class="token punctuation">-</span>> sys/def/13/b$unique <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> <span class="token punctuation">-</span>> NDB$INDEX_16_UI <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> <span class="token punctuation">-</span>> sys/def/13/PRIMARY <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> <span class="token punctuation">-</span>> NDB$INDEX_14_CUSTOM <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output">7 rows in set (0.15 sec)</span></code></pre>
</div>
<p>
When working with Disk Data tables, note that, in this context,
a tablespace or log file group is considered a root object. This
means that you must know the name of any tablespace or log file
group associated with a given table, or obtain this information
from
<a class="link" href="show-create-table.html" title="15.7.7.11 SHOW CREATE TABLE Statement">
<code class="literal">
SHOW CREATE TABLE
</code>
</a>
and then
querying
<a class="link" href="information-schema-files-table.html" title="28.3.15 The INFORMATION_SCHEMA FILES Table">
<code class="literal">
INFORMATION_SCHEMA.FILES
</code>
</a>
,
or similar means as shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa71670592"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SHOW</span> <span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> test<span class="token punctuation">.</span>dt_1\G
<span class="token output"><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span> 1. row <span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span>
Table<span class="token punctuation">:</span> dt_1
Create Table<span class="token punctuation">:</span> CREATE TABLE `dt_1` (
`member_id` int unsigned NOT NULL AUTO_INCREMENT,
`last_name` varchar(50) NOT NULL,
`first_name` varchar(50) NOT NULL,
`dob` date NOT NULL,
`joined` date NOT NULL,
PRIMARY KEY (`member_id`),
KEY `last_name` (`last_name`,`first_name`)
) /<span class="token punctuation">*</span>!50100 TABLESPACE `ts_1` STORAGE DISK <span class="token punctuation">*</span>/ ENGINE=ndbcluster DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
</span><span class="token output">1 row in set (0.00 sec)</span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token keyword">DISTINCT</span> TABLESPACE_NAME<span class="token punctuation">,</span> LOGFILE_GROUP_NAME
<span class="token prompt"> -></span> <span class="token keyword">FROM</span> INFORMATION_SCHEMA<span class="token punctuation">.</span>FILES <span class="token keyword">WHERE</span> TABLESPACE_NAME<span class="token operator">=</span><span class="token string">'ts_1'</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> TABLESPACE_NAME <span class="token punctuation">|</span> LOGFILE_GROUP_NAME <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> ts_1 <span class="token punctuation">|</span> lg_1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output">1 row in set (0.00 sec)</span></code></pre>
</div>
<p>
Now you can obtain hierarchical information for the table,
tablespace, and log file group like this:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa60782020"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> indented_name <span class="token keyword">FROM</span> ndbinfo<span class="token punctuation">.</span>dict_obj_tree
<span class="token prompt"> -></span> <span class="token keyword">WHERE</span> root_name <span class="token operator">=</span> <span class="token string">'test/def/dt_1'</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> indented_name <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> test/def/dt_1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> <span class="token punctuation">-</span>> sys/def/23/last_name <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> <span class="token punctuation">-</span>> NDB$INDEX_25_CUSTOM <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> <span class="token punctuation">-</span>> sys/def/23/PRIMARY <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> <span class="token punctuation">-</span>> NDB$INDEX_24_CUSTOM <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output">5 rows in set (0.15 sec)</span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> indented_name <span class="token keyword">FROM</span> ndbinfo<span class="token punctuation">.</span>dict_obj_tree
<span class="token prompt"> -></span> <span class="token keyword">WHERE</span> root_name <span class="token operator">=</span> <span class="token string">'ts_1'</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> indented_name <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> ts_1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> <span class="token punctuation">-</span>> data_1.dat <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> <span class="token punctuation">-</span>> data_2.dat <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output">3 rows in set (0.17 sec)</span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> indented_name <span class="token keyword">FROM</span> ndbinfo<span class="token punctuation">.</span>dict_obj_tree
<span class="token prompt"> -></span> <span class="token keyword">WHERE</span> root_name <span class="token operator">LIKE</span> <span class="token string">'lg_1'</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> indented_name <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> lg_1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> <span class="token punctuation">-</span>> undo_1.log <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> <span class="token punctuation">-</span>> undo_2.log <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output">3 rows in set (0.16 sec)</span></code></pre>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-metadata-locks-table.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="performance-schema-metadata-locks-table">
</a>
29.12.13.3 The metadata_locks Table
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045070362256">
</a>
<a class="indexterm" name="idm46045070360768">
</a>
<a class="indexterm" name="idm46045070359280">
</a>
<p>
MySQL uses metadata locking to manage concurrent access to
database objects and to ensure data consistency; see
<a class="xref" href="metadata-locking.html" title="10.11.4 Metadata Locking">
Section 10.11.4, “Metadata Locking”
</a>
. Metadata locking applies
not just to tables, but also to schemas, stored programs
(procedures, functions, triggers, scheduled events),
tablespaces, user locks acquired with the
<a class="link" href="locking-functions.html#function_get-lock">
<code class="literal">
GET_LOCK()
</code>
</a>
function (see
<a class="xref" href="locking-functions.html" title="14.14 Locking Functions">
Section 14.14, “Locking Functions”
</a>
), and locks acquired with
the locking service described in
<a class="xref" href="locking-service.html" title="7.6.9.1 The Locking Service">
Section 7.6.9.1, “The Locking Service”
</a>
.
</p>
<p>
The Performance Schema exposes metadata lock information
through the
<a class="link" href="performance-schema-metadata-locks-table.html" title="29.12.13.3 The metadata_locks Table">
<code class="literal">
metadata_locks
</code>
</a>
table:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Locks that have been granted (shows which sessions own
which current metadata locks).
</p>
</li>
<li class="listitem">
<p>
Locks that have been requested but not yet granted (shows
which sessions are waiting for which metadata locks).
</p>
</li>
<li class="listitem">
<p>
Lock requests that have been killed by the deadlock
detector.
</p>
</li>
<li class="listitem">
<p>
Lock requests that have timed out and are waiting for the
requesting session's lock request to be discarded.
</p>
</li>
</ul>
</div>
<p>
This information enables you to understand metadata lock
dependencies between sessions. You can see not only which lock
a session is waiting for, but which session currently holds
that lock.
</p>
<p>
The
<a class="link" href="performance-schema-metadata-locks-table.html" title="29.12.13.3 The metadata_locks Table">
<code class="literal">
metadata_locks
</code>
</a>
table is read
only and cannot be updated. It is autosized by default; to
configure the table size, set the
<a class="link" href="performance-schema-system-variables.html#sysvar_performance_schema_max_metadata_locks">
<code class="literal">
performance_schema_max_metadata_locks
</code>
</a>
system variable at server startup.
</p>
<p>
Metadata lock instrumentation uses the
<code class="literal">
wait/lock/metadata/sql/mdl
</code>
instrument,
which is enabled by default.
</p>
<p>
To control metadata lock instrumentation state at server
startup, use lines like these in your
<code class="filename">
my.cnf
</code>
file:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Enable:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-ini"><div class="docs-select-all right" id="sa72718788"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-ini"><span class="token selector">[mysqld]</span>
<span class="token constant">performance-schema-instrument</span><span class="token attr-value"><span class="token punctuation">=</span>'wait/lock/metadata/sql/mdl=ON'</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
Disable:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-ini"><div class="docs-select-all right" id="sa78480354"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-ini"><span class="token selector">[mysqld]</span>
<span class="token constant">performance-schema-instrument</span><span class="token attr-value"><span class="token punctuation">=</span>'wait/lock/metadata/sql/mdl=OFF'</span></code></pre>
</div>
</li>
</ul>
</div>
<p>
To control metadata lock instrumentation state at runtime,
update the
<a class="link" href="performance-schema-setup-instruments-table.html" title="29.12.2.3 The setup_instruments Table">
<code class="literal">
setup_instruments
</code>
</a>
table:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Enable:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa45781601"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> performance_schema<span class="token punctuation">.</span>setup_instruments
<span class="token keyword">SET</span> ENABLED <span class="token operator">=</span> <span class="token string">'YES'</span><span class="token punctuation">,</span> TIMED <span class="token operator">=</span> <span class="token string">'YES'</span>
<span class="token keyword">WHERE</span> <span class="token keyword">NAME</span> <span class="token operator">=</span> <span class="token string">'wait/lock/metadata/sql/mdl'</span><span class="token punctuation">;</span></code></pre>
</div>
</li>
<li class="listitem">
<p>
Disable:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa93382232"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">UPDATE</span> performance_schema<span class="token punctuation">.</span>setup_instruments
<span class="token keyword">SET</span> ENABLED <span class="token operator">=</span> <span class="token string">'NO'</span><span class="token punctuation">,</span> TIMED <span class="token operator">=</span> <span class="token string">'NO'</span>
<span class="token keyword">WHERE</span> <span class="token keyword">NAME</span> <span class="token operator">=</span> <span class="token string">'wait/lock/metadata/sql/mdl'</span><span class="token punctuation">;</span></code></pre>
</div>
</li>
</ul>
</div>
<p>
The Performance Schema maintains
<a class="link" href="performance-schema-metadata-locks-table.html" title="29.12.13.3 The metadata_locks Table">
<code class="literal">
metadata_locks
</code>
</a>
table content as
follows, using the
<code class="literal">
LOCK_STATUS
</code>
column to
indicate the status of each lock:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
When a metadata lock is requested and obtained
immediately, a row with a status of
<code class="literal">
GRANTED
</code>
is inserted.
</p>
</li>
<li class="listitem">
<p>
When a metadata lock is requested and not obtained
immediately, a row with a status of
<code class="literal">
PENDING
</code>
is inserted.
</p>
</li>
<li class="listitem">
<p>
When a metadata lock previously requested is granted, its
row status is updated to
<code class="literal">
GRANTED
</code>
.
</p>
</li>
<li class="listitem">
<p>
When a metadata lock is released, its row is deleted.
</p>
</li>
<li class="listitem">
<p>
When a pending lock request is canceled by the deadlock
detector to break a deadlock
(
<a class="ulink" href="/doc/mysql-errors/8.4/en/server-error-reference.html#error_er_lock_deadlock" target="_top">
<code class="literal">
ER_LOCK_DEADLOCK
</code>
</a>
), its
row status is updated from
<code class="literal">
PENDING
</code>
to
<code class="literal">
VICTIM
</code>
.
</p>
</li>
<li class="listitem">
<p>
When a pending lock request times out
(
<a class="ulink" href="/doc/mysql-errors/8.4/en/server-error-reference.html#error_er_lock_wait_timeout" target="_top">
<code class="literal">
ER_LOCK_WAIT_TIMEOUT
</code>
</a>
),
its row status is updated from
<code class="literal">
PENDING
</code>
to
<code class="literal">
TIMEOUT
</code>
.
</p>
</li>
<li class="listitem">
<p>
When granted lock or pending lock request is killed, its
row status is updated from
<code class="literal">
GRANTED
</code>
or
<code class="literal">
PENDING
</code>
to
<code class="literal">
KILLED
</code>
.
</p>
</li>
<li class="listitem">
<p>
The
<code class="literal">
VICTIM
</code>
,
<code class="literal">
TIMEOUT
</code>
,
and
<code class="literal">
KILLED
</code>
status values are brief and
signify that the lock row is about to be deleted.
</p>
</li>
<li class="listitem">
<p>
The
<code class="literal">
PRE_ACQUIRE_NOTIFY
</code>
and
<code class="literal">
POST_RELEASE_NOTIFY
</code>
status values are
brief and signify that the metadata locking subsubsystem
is notifying interested storage engines while entering
lock acquisition operations or leaving lock release
operations.
</p>
</li>
</ul>
</div>
<p>
The
<a class="link" href="performance-schema-metadata-locks-table.html" title="29.12.13.3 The metadata_locks Table">
<code class="literal">
metadata_locks
</code>
</a>
table has
these columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
OBJECT_TYPE
</code>
</p>
<p>
The type of lock used in the metadata lock subsystem. The
value is one of
<code class="literal">
GLOBAL
</code>
,
<code class="literal">
SCHEMA
</code>
,
<code class="literal">
TABLE
</code>
,
<code class="literal">
FUNCTION
</code>
,
<code class="literal">
PROCEDURE
</code>
,
<code class="literal">
TRIGGER
</code>
(currently unused),
<code class="literal">
EVENT
</code>
,
<code class="literal">
COMMIT
</code>
,
<code class="literal">
USER LEVEL LOCK
</code>
,
<code class="literal">
TABLESPACE
</code>
,
<code class="literal">
BACKUP
LOCK
</code>
, or
<code class="literal">
LOCKING SERVICE
</code>
.
</p>
<p>
A value of
<code class="literal">
USER LEVEL LOCK
</code>
indicates a
lock acquired with
<a class="link" href="locking-functions.html#function_get-lock">
<code class="literal">
GET_LOCK()
</code>
</a>
. A value of
<code class="literal">
LOCKING SERVICE
</code>
indicates a lock
acquired with the locking service described in
<a class="xref" href="locking-service.html" title="7.6.9.1 The Locking Service">
Section 7.6.9.1, “The Locking Service”
</a>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
OBJECT_SCHEMA
</code>
</p>
<p>
The schema that contains the object.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
OBJECT_NAME
</code>
</p>
<p>
The name of the instrumented object.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
OBJECT_INSTANCE_BEGIN
</code>
</p>
<p>
The address in memory of the instrumented object.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LOCK_TYPE
</code>
</p>
<p>
The lock type from the metadata lock subsystem. The value
is one of
<code class="literal">
INTENTION_EXCLUSIVE
</code>
,
<code class="literal">
SHARED
</code>
,
<code class="literal">
SHARED_HIGH_PRIO
</code>
,
<code class="literal">
SHARED_READ
</code>
,
<code class="literal">
SHARED_WRITE
</code>
,
<code class="literal">
SHARED_UPGRADABLE
</code>
,
<code class="literal">
SHARED_NO_WRITE
</code>
,
<code class="literal">
SHARED_NO_READ_WRITE
</code>
, or
<code class="literal">
EXCLUSIVE
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LOCK_DURATION
</code>
</p>
<p>
The lock duration from the metadata lock subsystem. The
value is one of
<code class="literal">
STATEMENT
</code>
,
<code class="literal">
TRANSACTION
</code>
, or
<code class="literal">
EXPLICIT
</code>
. The
<code class="literal">
STATEMENT
</code>
and
<code class="literal">
TRANSACTION
</code>
values signify locks that
are released implicitly at statement or transaction end,
respectively. The
<code class="literal">
EXPLICIT
</code>
value
signifies locks that survive statement or transaction end
and are released by explicit action, such as global locks
acquired with
<a class="link" href="flush.html#flush-tables-with-read-lock">
<code class="literal">
FLUSH TABLES WITH READ
LOCK
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
LOCK_STATUS
</code>
</p>
<p>
The lock status from the metadata lock subsystem. The
value is one of
<code class="literal">
PENDING
</code>
,
<code class="literal">
GRANTED
</code>
,
<code class="literal">
VICTIM
</code>
,
<code class="literal">
TIMEOUT
</code>
,
<code class="literal">
KILLED
</code>
,
<code class="literal">
PRE_ACQUIRE_NOTIFY
</code>
, or
<code class="literal">
POST_RELEASE_NOTIFY
</code>
. The Performance
Schema assigns these values as described previously.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SOURCE
</code>
</p>
<p>
The name of the source file containing the instrumented
code that produced the event and the line number in the
file at which the instrumentation occurs. This enables you
to check the source to determine exactly what code is
involved.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
OWNER_THREAD_ID
</code>
</p>
<p>
The thread requesting a metadata lock.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
OWNER_EVENT_ID
</code>
</p>
<p>
The event requesting a metadata lock.
</p>
</li>
</ul>
</div>
<p>
The
<a class="link" href="performance-schema-metadata-locks-table.html" title="29.12.13.3 The metadata_locks Table">
<code class="literal">
metadata_locks
</code>
</a>
table has
these indexes:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Primary key on (
<code class="literal">
OBJECT_INSTANCE_BEGIN
</code>
)
</p>
</li>
<li class="listitem">
<p>
Index on (
<code class="literal">
OBJECT_TYPE
</code>
,
<code class="literal">
OBJECT_SCHEMA
</code>
,
<code class="literal">
OBJECT_NAME
</code>
)
</p>
</li>
<li class="listitem">
<p>
Index on (
<code class="literal">
OWNER_THREAD_ID
</code>
,
<code class="literal">
OWNER_EVENT_ID
</code>
)
</p>
</li>
</ul>
</div>
<p>
<a class="link" href="truncate-table.html" title="15.1.37 TRUNCATE TABLE Statement">
<code class="literal">
TRUNCATE TABLE
</code>
</a>
is not permitted
for the
<a class="link" href="performance-schema-metadata-locks-table.html" title="29.12.13.3 The metadata_locks Table">
<code class="literal">
metadata_locks
</code>
</a>
table.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/windows-testing.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="windows-testing">
</a>
2.3.3.9 Testing The MySQL Installation
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045331880240">
</a>
<a class="indexterm" name="idm46045331879200">
</a>
<p>
You can test whether the MySQL server is working by executing
any of the following commands:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-terminal"><div class="docs-select-all right" id="sa76860232"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal"><span class="token prompt">C:\></span> <span class="token atrule">"C:\Program Files\MySQL\MySQL Server 8.4\bin\mysqlshow"</span>
<span class="token prompt">C:\></span> <span class="token atrule">"C:\Program Files\MySQL\MySQL Server 8.4\bin\mysqlshow"</span> <span class="token property">-u</span> root mysql
<span class="token prompt">C:\></span> <span class="token atrule">"C:\Program Files\MySQL\MySQL Server 8.4\bin\mysqladmin"</span> version status proc
<span class="token prompt">C:\></span> <span class="token atrule">"C:\Program Files\MySQL\MySQL Server 8.4\bin\mysql"</span> test</code></pre>
</div>
<p>
If
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
is slow to respond to TCP/IP
connections from client programs, there is probably a problem
with your DNS. In this case, start
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
with the
<a class="link" href="server-system-variables.html#sysvar_skip_name_resolve">
<code class="literal">
skip_name_resolve
</code>
</a>
system variable enabled and use only
<code class="literal">
localhost
</code>
and IP addresses in the
<code class="literal">
Host
</code>
column of the MySQL grant tables. (Be
sure that an account exists that specifies an IP address or you
may not be able to connect.)
</p>
<p>
You can force a MySQL client to use a named-pipe connection
rather than TCP/IP by specifying the
<a class="link" href="connection-options.html#option_general_pipe">
<code class="option">
--pipe
</code>
</a>
or
<a class="link" href="connection-options.html#option_general_protocol">
<code class="option">
--protocol=PIPE
</code>
</a>
option, or by
specifying
<code class="literal">
.
</code>
(period) as the host name. Use
the
<a class="link" href="connection-options.html#option_general_socket">
<code class="option">
--socket
</code>
</a>
option to specify
the name of the pipe if you do not want to use the default pipe
name.
</p>
<p>
If you have set a password for the
<code class="literal">
root
</code>
account, deleted the anonymous account, or created a new user
account, then to connect to the MySQL server you must use the
appropriate
<code class="option">
-u
</code>
and
<code class="option">
-p
</code>
options
with the commands shown previously. See
<a class="xref" href="connecting.html" title="6.2.4 Connecting to the MySQL Server Using Command Options">
Section 6.2.4, “Connecting to the MySQL Server Using Command Options”
</a>
.
</p>
<p>
For more information about
<a class="link" href="mysqlshow.html" title="6.5.6 mysqlshow — Display Database, Table, and Column Information">
<span class="command">
<strong>
mysqlshow
</strong>
</span>
</a>
, see
<a class="xref" href="mysqlshow.html" title="6.5.6 mysqlshow — Display Database, Table, and Column Information">
Section 6.5.6, “mysqlshow — Display Database, Table, and Column Information”
</a>
.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/selecting-rows.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="selecting-rows">
</a>
5.3.4.2 Selecting Particular Rows
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045325266400">
</a>
<a class="indexterm" name="idm46045325264944">
</a>
<p>
As shown in the preceding section, it is easy to retrieve an
entire table. Just omit the
<code class="literal">
WHERE
</code>
clause
from the
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
statement. But
typically you don't want to see the entire table, particularly
when it becomes large. Instead, you're usually more interested
in answering a particular question, in which case you specify
some constraints on the information you want. Let's look at
some selection queries in terms of questions about your pets
that they answer.
</p>
<p>
You can select only particular rows from your table. For
example, if you want to verify the change that you made to
Bowser's birth date, select Bowser's record like this:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa98642804"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> pet <span class="token keyword">WHERE</span> <span class="token keyword">name</span> <span class="token operator">=</span> <span class="token string">'Bowser'</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> name <span class="token punctuation">|</span> owner <span class="token punctuation">|</span> species <span class="token punctuation">|</span> sex <span class="token punctuation">|</span> birth <span class="token punctuation">|</span> death <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> Bowser <span class="token punctuation">|</span> Diane <span class="token punctuation">|</span> dog <span class="token punctuation">|</span> m <span class="token punctuation">|</span> 1989<span class="token punctuation">-</span>08<span class="token punctuation">-</span>31 <span class="token punctuation">|</span> 1995<span class="token punctuation">-</span>07<span class="token punctuation">-</span>29 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
<p>
The output confirms that the year is correctly recorded as
1989, not 1979.
</p>
<p>
String comparisons normally are case-insensitive, so you can
specify the name as
<code class="literal">
'bowser'
</code>
,
<code class="literal">
'BOWSER'
</code>
, and so forth. The query result is
the same.
</p>
<p>
You can specify conditions on any column, not just
<code class="literal">
name
</code>
. For example, if you want to know
which animals were born during or after 1998, test the
<code class="literal">
birth
</code>
column:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa80507680"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> pet <span class="token keyword">WHERE</span> birth <span class="token operator">>=</span> <span class="token string">'1998-1-1'</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> name <span class="token punctuation">|</span> owner <span class="token punctuation">|</span> species <span class="token punctuation">|</span> sex <span class="token punctuation">|</span> birth <span class="token punctuation">|</span> death <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> Chirpy <span class="token punctuation">|</span> Gwen <span class="token punctuation">|</span> bird <span class="token punctuation">|</span> f <span class="token punctuation">|</span> 1998<span class="token punctuation">-</span>09<span class="token punctuation">-</span>11 <span class="token punctuation">|</span> NULL <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Puffball <span class="token punctuation">|</span> Diane <span class="token punctuation">|</span> hamster <span class="token punctuation">|</span> f <span class="token punctuation">|</span> 1999<span class="token punctuation">-</span>03<span class="token punctuation">-</span>30 <span class="token punctuation">|</span> NULL <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
<p>
You can combine conditions, for example, to locate female
dogs:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa36822217"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> pet <span class="token keyword">WHERE</span> species <span class="token operator">=</span> <span class="token string">'dog'</span> <span class="token operator">AND</span> sex <span class="token operator">=</span> <span class="token string">'f'</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> name <span class="token punctuation">|</span> owner <span class="token punctuation">|</span> species <span class="token punctuation">|</span> sex <span class="token punctuation">|</span> birth <span class="token punctuation">|</span> death <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> Buffy <span class="token punctuation">|</span> Harold <span class="token punctuation">|</span> dog <span class="token punctuation">|</span> f <span class="token punctuation">|</span> 1989<span class="token punctuation">-</span>05<span class="token punctuation">-</span>13 <span class="token punctuation">|</span> NULL <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
<p>
The preceding query uses the
<a class="link" href="logical-operators.html#operator_and">
<code class="literal">
AND
</code>
</a>
logical operator. There is also an
<a class="link" href="logical-operators.html#operator_or">
<code class="literal">
OR
</code>
</a>
operator:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa79652338"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> pet <span class="token keyword">WHERE</span> species <span class="token operator">=</span> <span class="token string">'snake'</span> <span class="token operator">OR</span> species <span class="token operator">=</span> <span class="token string">'bird'</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> name <span class="token punctuation">|</span> owner <span class="token punctuation">|</span> species <span class="token punctuation">|</span> sex <span class="token punctuation">|</span> birth <span class="token punctuation">|</span> death <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> Chirpy <span class="token punctuation">|</span> Gwen <span class="token punctuation">|</span> bird <span class="token punctuation">|</span> f <span class="token punctuation">|</span> 1998<span class="token punctuation">-</span>09<span class="token punctuation">-</span>11 <span class="token punctuation">|</span> NULL <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Whistler <span class="token punctuation">|</span> Gwen <span class="token punctuation">|</span> bird <span class="token punctuation">|</span> NULL <span class="token punctuation">|</span> 1997<span class="token punctuation">-</span>12<span class="token punctuation">-</span>09 <span class="token punctuation">|</span> NULL <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Slim <span class="token punctuation">|</span> Benny <span class="token punctuation">|</span> snake <span class="token punctuation">|</span> m <span class="token punctuation">|</span> 1996<span class="token punctuation">-</span>04<span class="token punctuation">-</span>29 <span class="token punctuation">|</span> NULL <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
<p>
<a class="link" href="logical-operators.html#operator_and">
<code class="literal">
AND
</code>
</a>
and
<a class="link" href="logical-operators.html#operator_or">
<code class="literal">
OR
</code>
</a>
may be intermixed, although
<a class="link" href="logical-operators.html#operator_and">
<code class="literal">
AND
</code>
</a>
has higher precedence than
<a class="link" href="logical-operators.html#operator_or">
<code class="literal">
OR
</code>
</a>
. If you use both operators, it
is a good idea to use parentheses to indicate explicitly how
conditions should be grouped:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa26866375"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">FROM</span> pet <span class="token keyword">WHERE</span> <span class="token punctuation">(</span>species <span class="token operator">=</span> <span class="token string">'cat'</span> <span class="token operator">AND</span> sex <span class="token operator">=</span> <span class="token string">'m'</span><span class="token punctuation">)</span>
<span class="token operator">OR</span> <span class="token punctuation">(</span>species <span class="token operator">=</span> <span class="token string">'dog'</span> <span class="token operator">AND</span> sex <span class="token operator">=</span> <span class="token string">'f'</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> name <span class="token punctuation">|</span> owner <span class="token punctuation">|</span> species <span class="token punctuation">|</span> sex <span class="token punctuation">|</span> birth <span class="token punctuation">|</span> death <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> Claws <span class="token punctuation">|</span> Gwen <span class="token punctuation">|</span> cat <span class="token punctuation">|</span> m <span class="token punctuation">|</span> 1994<span class="token punctuation">-</span>03<span class="token punctuation">-</span>17 <span class="token punctuation">|</span> NULL <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> Buffy <span class="token punctuation">|</span> Harold <span class="token punctuation">|</span> dog <span class="token punctuation">|</span> f <span class="token punctuation">|</span> 1989<span class="token punctuation">-</span>05<span class="token punctuation">-</span>13 <span class="token punctuation">|</span> NULL <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/repair-table.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="repair-table">
</a>
15.7.3.5 REPAIR TABLE Statement
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045172051664">
</a>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa48222045"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">REPAIR</span> <span class="token punctuation">[</span><span class="token keyword">NO_WRITE_TO_BINLOG</span> <span class="token operator">|</span> <span class="token keyword">LOCAL</span><span class="token punctuation">]</span>
<span class="token keyword">TABLE</span> <em class="replaceable">tbl_name</em> <span class="token punctuation">[</span><span class="token punctuation">,</span> <em class="replaceable">tbl_name</em><span class="token punctuation">]</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span>
<span class="token punctuation">[</span><span class="token keyword">QUICK</span><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">EXTENDED</span><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">USE_FRM</span><span class="token punctuation">]</span></code></pre>
</div>
<p>
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
repairs a possibly
corrupted table, for certain storage engines only.
</p>
<p>
This statement requires
<a class="link" href="privileges-provided.html#priv_select">
<code class="literal">
SELECT
</code>
</a>
and
<a class="link" href="privileges-provided.html#priv_insert">
<code class="literal">
INSERT
</code>
</a>
privileges for the
table.
</p>
<p>
Although normally you should never have to run
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
, if disaster
strikes, this statement is very likely to get back all your data
from a
<code class="literal">
MyISAM
</code>
table. If your tables become
corrupted often, try to find the reason for it, to eliminate the
need to use
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
. See
<a class="xref" href="crashing.html" title="B.3.3.3 What to Do If MySQL Keeps Crashing">
Section B.3.3.3, “What to Do If MySQL Keeps Crashing”
</a>
, and
<a class="xref" href="myisam-table-problems.html" title="18.2.4 MyISAM Table Problems">
Section 18.2.4, “MyISAM Table Problems”
</a>
.
</p>
<p>
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
checks the table to
see whether an upgrade is required. If so, it performs the
upgrade, following the same rules as
<a class="link" href="check-table.html" title="15.7.3.2 CHECK TABLE Statement">
<code class="literal">
CHECK TABLE ... FOR
UPGRADE
</code>
</a>
. See
<a class="xref" href="check-table.html" title="15.7.3.2 CHECK TABLE Statement">
Section 15.7.3.2, “CHECK TABLE Statement”
</a>
, for more
information.
</p>
<div class="important" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Important
</div>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Make a backup of a table before performing a table repair
operation; under some circumstances the operation might
cause data loss. Possible causes include but are not
limited to file system errors. See
<a class="xref" href="backup-and-recovery.html" title="Chapter 9 Backup and Recovery">
Chapter 9,
<i>
Backup and Recovery
</i>
</a>
.
</p>
</li>
<li class="listitem">
<p>
If the server exits during a
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR
TABLE
</code>
</a>
operation, it is essential after
restarting it that you immediately execute another
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
statement for
the table before performing any other operations on it. In
the worst case, you might have a new clean index file
without information about the data file, and then the next
operation you perform could overwrite the data file. This
is an unlikely but possible scenario that underscores the
value of making a backup first.
</p>
</li>
<li class="listitem">
<p>
In the event that a table on the source becomes corrupted
and you run
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
on
it, any resulting changes to the original table are
<span class="emphasis">
<em>
not
</em>
</span>
propagated to replicas.
</p>
</li>
</ul>
</div>
</div>
<a class="indexterm" name="idm46045172023712">
</a>
<a class="indexterm" name="idm46045172022208">
</a>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="xref" href="repair-table.html#repair-table-support" title="REPAIR TABLE Storage Engine and Partitioning Support">
REPAIR TABLE Storage Engine and Partitioning Support
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="repair-table.html#repair-table-options" title="REPAIR TABLE Options">
REPAIR TABLE Options
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="repair-table.html#repair-table-output" title="REPAIR TABLE Output">
REPAIR TABLE Output
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="repair-table.html#repair-table-table-repair-considerations" title="Table Repair Considerations">
Table Repair Considerations
</a>
</p>
</li>
</ul>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="repair-table-support">
</a>
REPAIR TABLE Storage Engine and Partitioning Support
</h5>
</div>
</div>
</div>
<a class="indexterm" name="idm46045172014464">
</a>
<a class="indexterm" name="idm46045172013008">
</a>
<p>
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
works for
<a class="link" href="myisam-storage-engine.html" title="18.2 The MyISAM Storage Engine">
<code class="literal">
MyISAM
</code>
</a>
,
<a class="link" href="archive-storage-engine.html" title="18.5 The ARCHIVE Storage Engine">
<code class="literal">
ARCHIVE
</code>
</a>
, and
<a class="link" href="csv-storage-engine.html" title="18.4 The CSV Storage Engine">
<code class="literal">
CSV
</code>
</a>
tables. For
<a class="link" href="myisam-storage-engine.html" title="18.2 The MyISAM Storage Engine">
<code class="literal">
MyISAM
</code>
</a>
tables, it has the same
effect as
<a class="link" href="myisamchk.html" title="6.6.4 myisamchk — MyISAM Table-Maintenance Utility">
<span class="command">
<strong>
myisamchk --recover
<em class="replaceable">
<code>
tbl_name
</code>
</em>
</strong>
</span>
</a>
by default. This
statement does not work with views.
</p>
<p>
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
is supported for
partitioned tables. However, the
<code class="literal">
USE_FRM
</code>
option cannot be used with this statement on a partitioned
table.
</p>
<p>
You can use
<code class="literal">
ALTER TABLE ... REPAIR
PARTITION
</code>
to repair one or more partitions; for more
information, see
<a class="xref" href="alter-table.html" title="15.1.9 ALTER TABLE Statement">
Section 15.1.9, “ALTER TABLE Statement”
</a>
, and
<a class="xref" href="partitioning-maintenance.html" title="26.3.4 Maintenance of Partitions">
Section 26.3.4, “Maintenance of Partitions”
</a>
.
</p>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="repair-table-options">
</a>
REPAIR TABLE Options
</h5>
</div>
</div>
</div>
<a class="indexterm" name="idm46045171997040">
</a>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
NO_WRITE_TO_BINLOG
</code>
or
<code class="literal">
LOCAL
</code>
</p>
<p>
By default, the server writes
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR
TABLE
</code>
</a>
statements to the binary log so that they
replicate to replicas. To suppress logging, specify the
optional
<code class="literal">
NO_WRITE_TO_BINLOG
</code>
keyword or
its alias
<code class="literal">
LOCAL
</code>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
QUICK
</code>
</p>
<p>
If you use the
<code class="literal">
QUICK
</code>
option,
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
tries to
repair only the index file, and not the data file. This
type of repair is like that done by
<a class="link" href="myisamchk.html" title="6.6.4 myisamchk — MyISAM Table-Maintenance Utility">
<span class="command">
<strong>
myisamchk
--recover --quick
</strong>
</span>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
EXTENDED
</code>
</p>
<p>
If you use the
<code class="literal">
EXTENDED
</code>
option, MySQL
creates the index row by row instead of creating one index
at a time with sorting. This type of repair is like that
done by
<a class="link" href="myisamchk.html" title="6.6.4 myisamchk — MyISAM Table-Maintenance Utility">
<span class="command">
<strong>
myisamchk --safe-recover
</strong>
</span>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
USE_FRM
</code>
</p>
<p>
The
<code class="literal">
USE_FRM
</code>
option is available for use
if the
<code class="filename">
.MYI
</code>
index file is missing or
if its header is corrupted. This option tells MySQL not to
trust the information in the
<code class="filename">
.MYI
</code>
file header and to re-create it using information from the
data dictionary. This kind of repair cannot be done with
<a class="link" href="myisamchk.html" title="6.6.4 myisamchk — MyISAM Table-Maintenance Utility">
<span class="command">
<strong>
myisamchk
</strong>
</span>
</a>
.
</p>
<div class="caution" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Caution
</div>
<p>
Use the
<code class="literal">
USE_FRM
</code>
option
<span class="emphasis">
<em>
only
</em>
</span>
if you cannot use regular
<code class="literal">
REPAIR
</code>
modes. Telling the server to
ignore the
<code class="filename">
.MYI
</code>
file makes
important table metadata stored in the
<code class="filename">
.MYI
</code>
unavailable to the repair
process, which can have deleterious consequences:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
The current
<code class="literal">
AUTO_INCREMENT
</code>
value
is lost.
</p>
</li>
<li class="listitem">
<p>
The link to deleted records in the table is lost,
which means that free space for deleted records
remains unoccupied thereafter.
</p>
</li>
<li class="listitem">
<p>
The
<code class="filename">
.MYI
</code>
header indicates
whether the table is compressed. If the server
ignores this information, it cannot tell that a
table is compressed and repair can cause change or
loss of table contents. This means that
<code class="literal">
USE_FRM
</code>
should not be used with
compressed tables. That should not be necessary,
anyway: Compressed tables are read only, so they
should not become corrupt.
</p>
</li>
</ul>
</div>
<p>
If you use
<code class="literal">
USE_FRM
</code>
for a table that
was created by a different version of the MySQL server
than the one you are currently running,
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
does not
attempt to repair the table. In this case, the result
set returned by
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR
TABLE
</code>
</a>
contains a line with a
<code class="literal">
Msg_type
</code>
value of
<code class="literal">
error
</code>
and a
<code class="literal">
Msg_text
</code>
value of
<code class="literal">
Failed
repairing incompatible .FRM file
</code>
.
</p>
<p>
If
<code class="literal">
USE_FRM
</code>
is used,
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
does not
check the table to see whether an upgrade is required.
</p>
</div>
</li>
</ul>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="repair-table-output">
</a>
REPAIR TABLE Output
</h5>
</div>
</div>
</div>
<a class="indexterm" name="idm46045171954336">
</a>
<p>
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
returns a result
set with the columns shown in the following table.
</p>
<div class="informaltable">
<table summary="Columns of the REPAIR TABLE result set.">
<colgroup>
<col style="width: 15%"/>
<col style="width: 60%"/>
</colgroup>
<thead>
<tr>
<th>
Column
</th>
<th>
Value
</th>
</tr>
</thead>
<tbody>
<tr>
<td>
<code class="literal">
Table
</code>
</td>
<td>
The table name
</td>
</tr>
<tr>
<td>
<code class="literal">
Op
</code>
</td>
<td>
Always
<code class="literal">
repair
</code>
</td>
</tr>
<tr>
<td>
<code class="literal">
Msg_type
</code>
</td>
<td>
<code class="literal">
status
</code>
,
<code class="literal">
error
</code>
,
<code class="literal">
info
</code>
,
<code class="literal">
note
</code>
, or
<code class="literal">
warning
</code>
</td>
</tr>
<tr>
<td>
<code class="literal">
Msg_text
</code>
</td>
<td>
An informational message
</td>
</tr>
</tbody>
</table>
</div>
<p>
The
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
statement
might produce many rows of information for each repaired
table. The last row has a
<code class="literal">
Msg_type
</code>
value of
<code class="literal">
status
</code>
and
<code class="literal">
Msg_test
</code>
normally should be
<code class="literal">
OK
</code>
. For a
<code class="literal">
MyISAM
</code>
table, if you do not get
<code class="literal">
OK
</code>
, you should try repairing it with
<a class="link" href="myisamchk.html" title="6.6.4 myisamchk — MyISAM Table-Maintenance Utility">
<span class="command">
<strong>
myisamchk --safe-recover
</strong>
</span>
</a>
.
(
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
does not
implement all the options of
<a class="link" href="myisamchk.html" title="6.6.4 myisamchk — MyISAM Table-Maintenance Utility">
<span class="command">
<strong>
myisamchk
</strong>
</span>
</a>
.
With
<a class="link" href="myisamchk.html" title="6.6.4 myisamchk — MyISAM Table-Maintenance Utility">
<span class="command">
<strong>
myisamchk --safe-recover
</strong>
</span>
</a>
, you can also
use options that
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
does not support, such as
<a class="link" href="myisamchk-repair-options.html#option_myisamchk_max-record-length">
<code class="option">
--max-record-length
</code>
</a>
.)
</p>
<p>
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
table catches and
throws any errors that occur while copying table statistics
from the old corrupted file to the newly created file. For
example. if the user ID of the owner of the
<code class="filename">
.MYD
</code>
or
<code class="filename">
.MYI
</code>
file is
different from the user ID of the
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
process,
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
generates
a "cannot change ownership of the file" error unless
<a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
<span class="command">
<strong>
mysqld
</strong>
</span>
</a>
is started by the
<code class="literal">
root
</code>
user.
</p>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="repair-table-table-repair-considerations">
</a>
Table Repair Considerations
</h5>
</div>
</div>
</div>
<p>
You may be able to increase
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR
TABLE
</code>
</a>
performance by setting certain system
variables. See
<a class="xref" href="repair-table-optimization.html" title="10.6.3 Optimizing REPAIR TABLE Statements">
Section 10.6.3, “Optimizing REPAIR TABLE Statements”
</a>
.
</p>
<p>
<a class="link" href="repair-table.html" title="15.7.3.5 REPAIR TABLE Statement">
<code class="literal">
REPAIR TABLE
</code>
</a>
upgrades a table
if it contains old temporal columns in pre-5.6.4 format;
namely, the
<a class="link" href="time.html" title="13.2.3 The TIME Type">
<code class="literal">
TIME
</code>
</a>
,
<a class="link" href="datetime.html" title="13.2.2 The DATE, DATETIME, and TIMESTAMP Types">
<code class="literal">
DATETIME
</code>
</a>
, and
<a class="link" href="datetime.html" title="13.2.2 The DATE, DATETIME, and TIMESTAMP Types">
<code class="literal">
TIMESTAMP
</code>
</a>
columns that lacked
support for fractional seconds precision.
</p>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-ndbinfo-hash-maps.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="mysql-cluster-ndbinfo-hash-maps">
</a>
25.6.17.38 The ndbinfo hash_maps Table
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045089168528">
</a>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
id
</code>
</p>
<p>
The hash map's unique ID
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
version
</code>
</p>
<p>
Hash map version (integer)
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
state
</code>
</p>
<p>
Hash map state; see
<a class="ulink" href="/doc/ndbapi/en/ndb-object.html#ndb-object-state" target="_top">
Object::State
</a>
for
values and descriptions.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
fq_name
</code>
</p>
<p>
The hash map's fully qualified name
</p>
</li>
</ul>
</div>
<p>
The
<code class="literal">
hash_maps
</code>
table is actually a view
consisting of the four columns having the same names of the
<a class="link" href="mysql-cluster-ndbinfo-dict-obj-info.html" title="25.6.17.25 The ndbinfo dict_obj_info Table">
<code class="literal">
dict_obj_info
</code>
</a>
table, as shown
here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa24421627"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">VIEW</span> hash_maps <span class="token keyword">AS</span>
<span class="token keyword">SELECT</span> id<span class="token punctuation">,</span> version<span class="token punctuation">,</span> state<span class="token punctuation">,</span> fq_name
<span class="token keyword">FROM</span> dict_obj_info
<span class="token keyword">WHERE</span> <span class="token keyword">type</span><span class="token operator">=</span><span class="token number">24</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true"># Hash map; defined in dict_obj_types</span></code></pre>
</div>
<p>
See the description of
<a class="link" href="mysql-cluster-ndbinfo-dict-obj-info.html" title="25.6.17.25 The ndbinfo dict_obj_info Table">
<code class="literal">
dict_obj_info
</code>
</a>
for more
information.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/show.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="show">
</a>
15.7.7 SHOW Statements
</h3>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="show-binary-log-status.html">
15.7.7.1 SHOW BINARY LOG STATUS Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-binary-logs.html">
15.7.7.2 SHOW BINARY LOGS Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-binlog-events.html">
15.7.7.3 SHOW BINLOG EVENTS Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-character-set.html">
15.7.7.4 SHOW CHARACTER SET Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-collation.html">
15.7.7.5 SHOW COLLATION Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-columns.html">
15.7.7.6 SHOW COLUMNS Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-create-database.html">
15.7.7.7 SHOW CREATE DATABASE Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-create-event.html">
15.7.7.8 SHOW CREATE EVENT Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-create-function.html">
15.7.7.9 SHOW CREATE FUNCTION Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-create-procedure.html">
15.7.7.10 SHOW CREATE PROCEDURE Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-create-table.html">
15.7.7.11 SHOW CREATE TABLE Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-create-trigger.html">
15.7.7.12 SHOW CREATE TRIGGER Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-create-user.html">
15.7.7.13 SHOW CREATE USER Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-create-view.html">
15.7.7.14 SHOW CREATE VIEW Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-databases.html">
15.7.7.15 SHOW DATABASES Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-engine.html">
15.7.7.16 SHOW ENGINE Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-engines.html">
15.7.7.17 SHOW ENGINES Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-errors.html">
15.7.7.18 SHOW ERRORS Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-events.html">
15.7.7.19 SHOW EVENTS Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-function-code.html">
15.7.7.20 SHOW FUNCTION CODE Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-function-status.html">
15.7.7.21 SHOW FUNCTION STATUS Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-grants.html">
15.7.7.22 SHOW GRANTS Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-index.html">
15.7.7.23 SHOW INDEX Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-master-status.html">
15.7.7.24 SHOW MASTER STATUS Statement (no longer supported)
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-open-tables.html">
15.7.7.25 SHOW OPEN TABLES Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-parse-tree.html">
15.7.7.26 SHOW PARSE_TREE Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-plugins.html">
15.7.7.27 SHOW PLUGINS Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-privileges.html">
15.7.7.28 SHOW PRIVILEGES Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-procedure-code.html">
15.7.7.29 SHOW PROCEDURE CODE Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-procedure-status.html">
15.7.7.30 SHOW PROCEDURE STATUS Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-processlist.html">
15.7.7.31 SHOW PROCESSLIST Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-profile.html">
15.7.7.32 SHOW PROFILE Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-profiles.html">
15.7.7.33 SHOW PROFILES Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-relaylog-events.html">
15.7.7.34 SHOW RELAYLOG EVENTS Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-replica-status.html">
15.7.7.35 SHOW REPLICA STATUS Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-replicas.html">
15.7.7.36 SHOW REPLICAS Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-status.html">
15.7.7.37 SHOW STATUS Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-table-status.html">
15.7.7.38 SHOW TABLE STATUS Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-tables.html">
15.7.7.39 SHOW TABLES Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-triggers.html">
15.7.7.40 SHOW TRIGGERS Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-variables.html">
15.7.7.41 SHOW VARIABLES Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="show-warnings.html">
15.7.7.42 SHOW WARNINGS Statement
</a>
</span>
</dt>
</dl>
</div>
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<a class="indexterm" name="idm46045171311456">
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</a>
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</a>
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</a>
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</a>
<a class="indexterm" name="idm46045171276400">
</a>
<a class="indexterm" name="idm46045171275312">
</a>
<a class="indexterm" name="idm46045171274240">
</a>
<a class="indexterm" name="idm46045171273168">
</a>
<a class="indexterm" name="idm46045171272080">
</a>
<a class="indexterm" name="idm46045171271008">
</a>
<a class="indexterm" name="idm46045171269920">
</a>
<a class="indexterm" name="idm46045171268848">
</a>
<a class="indexterm" name="idm46045171267776">
</a>
<a class="indexterm" name="idm46045171266688">
</a>
<a class="indexterm" name="idm46045171265616">
</a>
<a class="indexterm" name="idm46045171264528">
</a>
<p>
<a class="link" href="show.html" title="15.7.7 SHOW Statements">
<code class="literal">
SHOW
</code>
</a>
has many forms that provide
information about databases, tables, columns, or status
information about the server. This section describes those
following:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa67334323"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SHOW</span> <span class="token datatype">BINARY</span> LOG <span class="token keyword">STATUS</span>
<span class="token keyword">SHOW</span> <span class="token datatype">BINARY</span> <span class="token keyword">LOGS</span>
<span class="token keyword">SHOW</span> <span class="token keyword">BINLOG</span> <span class="token keyword">EVENTS</span> <span class="token punctuation">[</span><span class="token keyword">IN</span> <span class="token string">'<em class="replaceable">log_name</em>'</span><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">FROM</span> <em class="replaceable">pos</em><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">LIMIT</span> <span class="token punctuation">[</span><span class="token keyword"><em class="replaceable">offset</em></span><span class="token punctuation">,</span><span class="token punctuation">]</span> <span class="token keyword"><em class="replaceable">row_count</em></span><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> {<span class="token keyword">CHARACTER</span> <span class="token keyword">SET</span> <span class="token operator">|</span> <span class="token keyword">CHARSET</span>} <span class="token punctuation">[</span><em class="replaceable">like_or_where</em><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token keyword">COLLATION</span> <span class="token punctuation">[</span><em class="replaceable">like_or_where</em><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token punctuation">[</span><span class="token keyword">FULL</span><span class="token punctuation">]</span> <span class="token keyword">COLUMNS</span> <span class="token keyword">FROM</span> <em class="replaceable">tbl_name</em> <span class="token punctuation">[</span><span class="token keyword">FROM</span> <em class="replaceable">db_name</em><span class="token punctuation">]</span> <span class="token punctuation">[</span><em class="replaceable">like_or_where</em><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token keyword">CREATE</span> <span class="token keyword">DATABASE</span> <em class="replaceable">db_name</em>
<span class="token keyword">SHOW</span> <span class="token keyword">CREATE</span> <span class="token keyword">EVENT</span> <em class="replaceable">event_name</em>
<span class="token keyword">SHOW</span> <span class="token keyword">CREATE</span> <span class="token keyword">FUNCTION</span> <em class="replaceable">func_name</em>
<span class="token keyword">SHOW</span> <span class="token keyword">CREATE</span> <span class="token keyword">PROCEDURE</span> <em class="replaceable">proc_name</em>
<span class="token keyword">SHOW</span> <span class="token keyword">CREATE</span> <span class="token keyword">TABLE</span> <em class="replaceable">tbl_name</em>
<span class="token keyword">SHOW</span> <span class="token keyword">CREATE</span> <span class="token keyword">TRIGGER</span> <em class="replaceable">trigger_name</em>
<span class="token keyword">SHOW</span> <span class="token keyword">CREATE</span> <span class="token keyword">VIEW</span> <em class="replaceable">view_name</em>
<span class="token keyword">SHOW</span> <span class="token keyword">DATABASES</span> <span class="token punctuation">[</span><em class="replaceable">like_or_where</em><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token keyword">ENGINE</span> <em class="replaceable">engine_name</em> {<span class="token keyword">STATUS</span> <span class="token operator">|</span> <span class="token keyword">MUTEX</span>}
<span class="token keyword">SHOW</span> <span class="token punctuation">[</span><span class="token keyword">STORAGE</span><span class="token punctuation">]</span> <span class="token keyword">ENGINES</span>
<span class="token keyword">SHOW</span> <span class="token keyword">ERRORS</span> <span class="token punctuation">[</span><span class="token keyword">LIMIT</span> <span class="token punctuation">[</span><span class="token keyword"><em class="replaceable">offset</em></span><span class="token punctuation">,</span><span class="token punctuation">]</span> <span class="token keyword"><em class="replaceable">row_count</em></span><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token keyword">EVENTS</span>
<span class="token keyword">SHOW</span> <span class="token keyword">FUNCTION</span> <span class="token keyword">CODE</span> <em class="replaceable">func_name</em>
<span class="token keyword">SHOW</span> <span class="token keyword">FUNCTION</span> <span class="token keyword">STATUS</span> <span class="token punctuation">[</span><em class="replaceable">like_or_where</em><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token keyword">GRANTS</span> <span class="token keyword">FOR</span> <span class="token keyword"><em class="replaceable">user</em></span>
<span class="token keyword">SHOW</span> <span class="token keyword">INDEX</span> <span class="token keyword">FROM</span> <em class="replaceable">tbl_name</em> <span class="token punctuation">[</span><span class="token keyword">FROM</span> <em class="replaceable">db_name</em><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token keyword">OPEN</span> <span class="token keyword">TABLES</span> <span class="token punctuation">[</span><span class="token keyword">FROM</span> <em class="replaceable">db_name</em><span class="token punctuation">]</span> <span class="token punctuation">[</span><em class="replaceable">like_or_where</em><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token keyword">PLUGINS</span>
<span class="token keyword">SHOW</span> <span class="token keyword">PROCEDURE</span> <span class="token keyword">CODE</span> <em class="replaceable">proc_name</em>
<span class="token keyword">SHOW</span> <span class="token keyword">PROCEDURE</span> <span class="token keyword">STATUS</span> <span class="token punctuation">[</span><em class="replaceable">like_or_where</em><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token keyword">PRIVILEGES</span>
<span class="token keyword">SHOW</span> <span class="token punctuation">[</span><span class="token keyword">FULL</span><span class="token punctuation">]</span> <span class="token keyword">PROCESSLIST</span>
<span class="token keyword">SHOW</span> <span class="token keyword">PROFILE</span> <span class="token punctuation">[</span><span class="token keyword"><em class="replaceable">types</em></span><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">FOR</span> <span class="token keyword">QUERY</span> <em class="replaceable">n</em><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">OFFSET</span> <em class="replaceable">n</em><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">LIMIT</span> <em class="replaceable">n</em><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token keyword">PROFILES</span>
<span class="token keyword">SHOW</span> <span class="token keyword">RELAYLOG</span> <span class="token keyword">EVENTS</span> <span class="token punctuation">[</span><span class="token keyword">IN</span> <span class="token string">'<em class="replaceable">log_name</em>'</span><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">FROM</span> <em class="replaceable">pos</em><span class="token punctuation">]</span> <span class="token punctuation">[</span><span class="token keyword">LIMIT</span> <span class="token punctuation">[</span><span class="token keyword"><em class="replaceable">offset</em></span><span class="token punctuation">,</span><span class="token punctuation">]</span> <span class="token keyword"><em class="replaceable">row_count</em></span><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token keyword">REPLICA</span> <span class="token keyword">STATUS</span> <span class="token punctuation">[</span><span class="token keyword">FOR</span> <span class="token keyword">CHANNEL</span> <span class="token keyword"><em class="replaceable">channel</em></span><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token keyword">REPLICAS</span>
<span class="token keyword">SHOW</span> <span class="token punctuation">[</span><span class="token keyword">GLOBAL</span> <span class="token operator">|</span> <span class="token keyword">SESSION</span><span class="token punctuation">]</span> <span class="token keyword">STATUS</span> <span class="token punctuation">[</span><em class="replaceable">like_or_where</em><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token keyword">TABLE</span> <span class="token keyword">STATUS</span> <span class="token punctuation">[</span><span class="token keyword">FROM</span> <em class="replaceable">db_name</em><span class="token punctuation">]</span> <span class="token punctuation">[</span><em class="replaceable">like_or_where</em><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token punctuation">[</span><span class="token keyword">FULL</span><span class="token punctuation">]</span> <span class="token keyword">TABLES</span> <span class="token punctuation">[</span><span class="token keyword">FROM</span> <em class="replaceable">db_name</em><span class="token punctuation">]</span> <span class="token punctuation">[</span><em class="replaceable">like_or_where</em><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token keyword">TRIGGERS</span> <span class="token punctuation">[</span><span class="token keyword">FROM</span> <em class="replaceable">db_name</em><span class="token punctuation">]</span> <span class="token punctuation">[</span><em class="replaceable">like_or_where</em><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token punctuation">[</span><span class="token keyword">GLOBAL</span> <span class="token operator">|</span> <span class="token keyword">SESSION</span><span class="token punctuation">]</span> <span class="token keyword">VARIABLES</span> <span class="token punctuation">[</span><em class="replaceable">like_or_where</em><span class="token punctuation">]</span>
<span class="token keyword">SHOW</span> <span class="token keyword">WARNINGS</span> <span class="token punctuation">[</span><span class="token keyword">LIMIT</span> <span class="token punctuation">[</span><span class="token keyword"><em class="replaceable">offset</em></span><span class="token punctuation">,</span><span class="token punctuation">]</span> <span class="token keyword"><em class="replaceable">row_count</em></span><span class="token punctuation">]</span>
<em class="replaceable">like_or_where</em>: {
<span class="token operator">LIKE</span> <span class="token string">'<em class="replaceable">pattern</em>'</span>
<span class="token operator">|</span> <span class="token keyword">WHERE</span> <em class="replaceable">expr</em>
}</code></pre>
</div>
<p>
If the syntax for a given
<a class="link" href="show.html" title="15.7.7 SHOW Statements">
<code class="literal">
SHOW
</code>
</a>
statement includes a
<a class="link" href="string-comparison-functions.html#operator_like">
<code class="literal">
LIKE
'
<em class="replaceable">
<code>
pattern
</code>
</em>
'
</code>
</a>
part,
<code class="literal">
'
<em class="replaceable">
<code>
pattern
</code>
</em>
'
</code>
is a
string that can contain the SQL
<code class="literal">
%
</code>
and
<code class="literal">
_
</code>
wildcard characters. The pattern is useful
for restricting statement output to matching values.
</p>
<p>
Several
<a class="link" href="show.html" title="15.7.7 SHOW Statements">
<code class="literal">
SHOW
</code>
</a>
statements also accept
a
<code class="literal">
WHERE
</code>
clause that provides more flexibility
in specifying which rows to display. See
<a class="xref" href="extended-show.html" title="28.8 Extensions to SHOW Statements">
Section 28.8, “Extensions to SHOW Statements”
</a>
.
</p>
<p>
In
<a class="link" href="show.html" title="15.7.7 SHOW Statements">
<code class="literal">
SHOW
</code>
</a>
statement results, user
names and host names are quoted using backticks (`).
</p>
<p>
Many MySQL APIs (such as PHP) enable you to treat the result
returned from a
<a class="link" href="show.html" title="15.7.7 SHOW Statements">
<code class="literal">
SHOW
</code>
</a>
statement as
you would a result set from a
<a class="link" href="select.html" title="15.2.13 SELECT Statement">
<code class="literal">
SELECT
</code>
</a>
; see
<a class="xref" href="connectors-apis.html" title="Chapter 31 Connectors and APIs">
Chapter 31,
<i>
Connectors and APIs
</i>
</a>
, or your API documentation for
more information. In addition, you can work in SQL with results
from queries on tables in the
<code class="literal">
INFORMATION_SCHEMA
</code>
database, which you cannot
easily do with results from
<a class="link" href="show.html" title="15.7.7 SHOW Statements">
<code class="literal">
SHOW
</code>
</a>
statements. See
<a class="xref" href="information-schema.html" title="Chapter 28 INFORMATION_SCHEMA Tables">
Chapter 28,
<i>
INFORMATION_SCHEMA Tables
</i>
</a>
.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/account-management-statements.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="account-management-statements">
</a>
15.7.1 Account Management Statements
</h3>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="alter-user.html">
15.7.1.1 ALTER USER Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="create-role.html">
15.7.1.2 CREATE ROLE Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="create-user.html">
15.7.1.3 CREATE USER Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="drop-role.html">
15.7.1.4 DROP ROLE Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="drop-user.html">
15.7.1.5 DROP USER Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="grant.html">
15.7.1.6 GRANT Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="rename-user.html">
15.7.1.7 RENAME USER Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="revoke.html">
15.7.1.8 REVOKE Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="set-default-role.html">
15.7.1.9 SET DEFAULT ROLE Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="set-password.html">
15.7.1.10 SET PASSWORD Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="set-role.html">
15.7.1.11 SET ROLE Statement
</a>
</span>
</dt>
</dl>
</div>
<p>
MySQL account information is stored in the tables of the
<code class="literal">
mysql
</code>
system schema. This database and the
access control system are discussed extensively in
<a class="xref" href="server-administration.html" title="Chapter 7 MySQL Server Administration">
Chapter 7,
<i>
MySQL Server Administration
</i>
</a>
, which you should consult
for additional details.
</p>
<div class="important" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Important
</div>
<p>
Some MySQL releases introduce changes to the grant tables to add
new privileges or features. To make sure that you can take
advantage of any new capabilities, update your grant tables to
the current structure whenever you upgrade MySQL. See
<a class="xref" href="upgrading.html" title="Chapter 3 Upgrading MySQL">
Chapter 3,
<i>
Upgrading MySQL
</i>
</a>
.
</p>
</div>
<p>
When the
<a class="link" href="server-system-variables.html#sysvar_read_only">
<code class="literal">
read_only
</code>
</a>
system
variable is enabled, account-management statements require the
<a class="link" href="privileges-provided.html#priv_connection-admin">
<code class="literal">
CONNECTION_ADMIN
</code>
</a>
privilege (or the
deprecated
<a class="link" href="privileges-provided.html#priv_super">
<code class="literal">
SUPER
</code>
</a>
privilege), in
addition to any other required privileges. This is because they
modify tables in the
<code class="literal">
mysql
</code>
system schema.
</p>
<p>
Account management statements are atomic and crash safe. For more
information, see
<a class="xref" href="atomic-ddl.html" title="15.1.1 Atomic Data Definition Statement Support">
Section 15.1.1, “Atomic Data Definition Statement Support”
</a>
.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/symbolic-links.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="symbolic-links">
</a>
10.12.2 Using Symbolic Links
</h3>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="symbolic-links-to-databases.html">
10.12.2.1 Using Symbolic Links for Databases on Unix
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="symbolic-links-to-tables.html">
10.12.2.2 Using Symbolic Links for MyISAM Tables on Unix
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="windows-symbolic-links.html">
10.12.2.3 Using Symbolic Links for Databases on Windows
</a>
</span>
</dt>
</dl>
</div>
<a class="indexterm" name="idm46045222487280">
</a>
<a class="indexterm" name="idm46045222486208">
</a>
<p>
You can move databases or tables from the database directory to
other locations and replace them with symbolic links to the new
locations. You might want to do this, for example, to move a
database to a file system with more free space or increase the
speed of your system by spreading your tables to different
disks.
</p>
<p>
For
<code class="literal">
InnoDB
</code>
tables, use the
<code class="literal">
DATA
DIRECTORY
</code>
clause of the
<a class="link" href="create-table.html" title="15.1.20 CREATE TABLE Statement">
<code class="literal">
CREATE
TABLE
</code>
</a>
statement instead of symbolic links, as
explained in
<a class="xref" href="innodb-create-table-external.html" title="17.6.1.2 Creating Tables Externally">
Section 17.6.1.2, “Creating Tables Externally”
</a>
.
This new feature is a supported, cross-platform technique.
</p>
<p>
The recommended way to do this is to symlink entire database
directories to a different disk. Symlink
<code class="literal">
MyISAM
</code>
tables only as a last resort.
</p>
<p>
To determine the location of your data directory, use this
statement:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa86653043"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SHOW</span> <span class="token keyword">VARIABLES</span> <span class="token operator">LIKE</span> <span class="token string">'datadir'</span><span class="token punctuation">;</span></code></pre>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/optimizing-innodb-storage-layout.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="optimizing-innodb-storage-layout">
</a>
10.5.1 Optimizing Storage Layout for InnoDB Tables
</h3>
</div>
</div>
</div>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Once your data reaches a stable size, or a growing table has
increased by tens or some hundreds of megabytes, consider
using the
<code class="literal">
OPTIMIZE TABLE
</code>
statement to
reorganize the table and compact any wasted space. The
reorganized tables require less disk I/O to perform full
table scans. This is a straightforward technique that can
improve performance when other techniques such as improving
index usage or tuning application code are not practical.
</p>
<p>
<code class="literal">
OPTIMIZE TABLE
</code>
copies the data part of
the table and rebuilds the indexes. The benefits come from
improved packing of data within indexes, and reduced
fragmentation within the tablespaces and on disk. The
benefits vary depending on the data in each table. You may
find that there are significant gains for some and not for
others, or that the gains decrease over time until you next
optimize the table. This operation can be slow if the table
is large or if the indexes being rebuilt do not fit into the
buffer pool. The first run after adding a lot of data to a
table is often much slower than later runs.
</p>
</li>
<li class="listitem">
<p>
In
<code class="literal">
InnoDB
</code>
, having a long
<code class="literal">
PRIMARY
KEY
</code>
(either a single column with a lengthy value,
or several columns that form a long composite value) wastes
a lot of disk space. The primary key value for a row is
duplicated in all the secondary index records that point to
the same row. (See
<a class="xref" href="innodb-index-types.html" title="17.6.2.1 Clustered and Secondary Indexes">
Section 17.6.2.1, “Clustered and Secondary Indexes”
</a>
.)
Create an
<code class="literal">
AUTO_INCREMENT
</code>
column as the
primary key if your primary key is long, or index a prefix
of a long
<code class="literal">
VARCHAR
</code>
column instead of the
entire column.
</p>
</li>
<li class="listitem">
<p>
Use the
<a class="link" href="char.html" title="13.3.2 The CHAR and VARCHAR Types">
<code class="literal">
VARCHAR
</code>
</a>
data type
instead of
<a class="link" href="char.html" title="13.3.2 The CHAR and VARCHAR Types">
<code class="literal">
CHAR
</code>
</a>
to store
variable-length strings or for columns with many
<code class="literal">
NULL
</code>
values. A
<a class="link" href="char.html" title="13.3.2 The CHAR and VARCHAR Types">
<code class="literal">
CHAR(
<em class="replaceable">
<code>
N
</code>
</em>
)
</code>
</a>
column always takes
<em class="replaceable">
<code>
N
</code>
</em>
characters
to store data, even if the string is shorter or its value is
<code class="literal">
NULL
</code>
. Smaller tables fit better in the
buffer pool and reduce disk I/O.
</p>
<p>
When using
<code class="literal">
COMPACT
</code>
row format (the
default
<code class="literal">
InnoDB
</code>
format) and
variable-length character sets, such as
<code class="literal">
utf8mb4
</code>
or
<code class="literal">
sjis
</code>
,
<a class="link" href="char.html" title="13.3.2 The CHAR and VARCHAR Types">
<code class="literal">
CHAR(
<em class="replaceable">
<code>
N
</code>
</em>
)
</code>
</a>
columns occupy a variable amount of space, but still at
least
<em class="replaceable">
<code>
N
</code>
</em>
bytes.
</p>
</li>
<li class="listitem">
<p>
For tables that are big, or contain lots of repetitive text
or numeric data, consider using
<code class="literal">
COMPRESSED
</code>
row format. Less disk I/O is
required to bring data into the buffer pool, or to perform
full table scans. Before making a permanent decision,
measure the amount of compression you can achieve by using
<code class="literal">
COMPRESSED
</code>
versus
<code class="literal">
COMPACT
</code>
row format.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/group-replication-flow-control.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="group-replication-flow-control">
</a>
20.7.2 Flow Control
</h3>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="group-replication-probes-and-statistics.html">
20.7.2.1 Probes and Statistics
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="group-replication-throttling.html">
20.7.2.2 Group Replication Throttling
</a>
</span>
</dt>
</dl>
</div>
<a class="indexterm" name="idm46045132221040">
</a>
<p>
Group Replication ensures that a transaction only commits after a
majority of the members in a group have received it and agreed on
the relative order between all transactions that were sent
concurrently. This approach works well if the total number of
writes to the group does not exceed the write capacity of any
member in the group. If it does and some of the members have less
write throughput than others, particularly less than the writer
members, those members can start lagging behind of the writers.
</p>
<p>
Having some members lagging behind the group brings some
problematic consequences, particularly, the reads on such members
may externalize very old data. Depending on why the member is
lagging behind, other members in the group may have to save more
or less replication context to be able to fulfil potential data
transfer requests from the slow member.
</p>
<p>
There is however a mechanism in the replication protocol to avoid
having too much distance, in terms of transactions applied,
between fast and slow members. This is known as the flow control
mechanism. It tries to address several goals:
</p>
<div class="orderedlist">
<ol class="orderedlist" type="1">
<li class="listitem">
<p>
to keep the members close enough to make buffering and
de-synchronization between members a small problem;
</p>
</li>
<li class="listitem">
<p>
to adapt quickly to changing conditions like different
workloads or more writers in the group;
</p>
</li>
<li class="listitem">
<p>
to give each member a fair share of the available write
capacity;
</p>
</li>
<li class="listitem">
<p>
to not reduce throughput more than strictly necessary to avoid
wasting resources.
</p>
</li>
</ol>
</div>
<p>
Given the design of Group Replication, the decision whether to
throttle or not may be decided taking into account two work
queues:
<span class="emphasis">
<em>
(i)
</em>
</span>
the
<span class="emphasis">
<em>
certification
</em>
</span>
queue;
<span class="emphasis">
<em>
(ii)
</em>
</span>
and on the binary log
<span class="emphasis">
<em>
applier
</em>
</span>
queue. Whenever the size of one of
these queues exceeds the user-defined threshold, the throttling
mechanism is triggered. Only configure:
<span class="emphasis">
<em>
(i)
</em>
</span>
whether to do flow control at the certifier or at the applier
level, or both; and
<span class="emphasis">
<em>
(ii)
</em>
</span>
what is the
threshold for each queue.
</p>
<p>
The flow control depends on two basic mechanisms:
</p>
<div class="orderedlist">
<ol class="orderedlist" type="1">
<li class="listitem">
<p>
the monitoring of members to collect some statistics on
throughput and queue sizes of all group members to make
educated guesses on what is the maximum write pressure each
member should be subjected to;
</p>
</li>
<li class="listitem">
<p>
the throttling of members that are trying to write beyond
their fair-share of the available capacity at each moment in
time.
</p>
</li>
</ol>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/sql-transactional-statements.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h2 class="title">
<a name="sql-transactional-statements">
</a>
15.3 Transactional and Locking Statements
</h2>
</div>
</div>
</div>
<div class="toc">
<dl class="toc">
<dt>
<span class="section">
<a href="commit.html">
15.3.1 START TRANSACTION, COMMIT, and ROLLBACK Statements
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="cannot-roll-back.html">
15.3.2 Statements That Cannot Be Rolled Back
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="implicit-commit.html">
15.3.3 Statements That Cause an Implicit Commit
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="savepoint.html">
15.3.4 SAVEPOINT, ROLLBACK TO SAVEPOINT, and RELEASE SAVEPOINT Statements
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="lock-instance-for-backup.html">
15.3.5 LOCK INSTANCE FOR BACKUP and UNLOCK INSTANCE Statements
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="lock-tables.html">
15.3.6 LOCK TABLES and UNLOCK TABLES Statements
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="set-transaction.html">
15.3.7 SET TRANSACTION Statement
</a>
</span>
</dt>
<dt>
<span class="section">
<a href="xa.html">
15.3.8 XA Transactions
</a>
</span>
</dt>
</dl>
</div>
<p>
MySQL supports local transactions (within a given client session)
through statements such as
<a class="link" href="commit.html" title="15.3.1 START TRANSACTION, COMMIT, and ROLLBACK Statements">
<code class="literal">
SET autocommit
</code>
</a>
,
<a class="link" href="commit.html" title="15.3.1 START TRANSACTION, COMMIT, and ROLLBACK Statements">
<code class="literal">
START TRANSACTION
</code>
</a>
,
<a class="link" href="commit.html" title="15.3.1 START TRANSACTION, COMMIT, and ROLLBACK Statements">
<code class="literal">
COMMIT
</code>
</a>
, and
<a class="link" href="commit.html" title="15.3.1 START TRANSACTION, COMMIT, and ROLLBACK Statements">
<code class="literal">
ROLLBACK
</code>
</a>
. See
<a class="xref" href="commit.html" title="15.3.1 START TRANSACTION, COMMIT, and ROLLBACK Statements">
Section 15.3.1, “START TRANSACTION, COMMIT, and ROLLBACK Statements”
</a>
. XA transaction support enables MySQL to
participate in distributed transactions as well. See
<a class="xref" href="xa.html" title="15.3.8 XA Transactions">
Section 15.3.8, “XA Transactions”
</a>
.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/password-security-admin.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="password-security-admin">
</a>
8.1.2.2 Administrator Guidelines for Password Security
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045252849264">
</a>
<p>
Database administrators should use the following guidelines to
keep passwords secure.
</p>
<p>
MySQL stores passwords for user accounts in the
<code class="literal">
mysql.user
</code>
system table. Access to this table
should never be granted to any nonadministrative accounts.
</p>
<p>
Account passwords can be expired so that users must reset them.
See
<a class="xref" href="password-management.html" title="8.2.15 Password Management">
Section 8.2.15, “Password Management”
</a>
, and
<a class="xref" href="expired-password-handling.html" title="8.2.16 Server Handling of Expired Passwords">
Section 8.2.16, “Server Handling of Expired Passwords”
</a>
.
</p>
<p>
The
<code class="literal">
validate_password
</code>
plugin can be used to
enforce a policy on acceptable password. See
<a class="xref" href="validate-password.html" title="8.4.3 The Password Validation Component">
Section 8.4.3, “The Password Validation Component”
</a>
.
</p>
<p>
A user who has access to modify the plugin directory (the value
of the
<a class="link" href="server-system-variables.html#sysvar_plugin_dir">
<code class="literal">
plugin_dir
</code>
</a>
system
variable) or the
<code class="filename">
my.cnf
</code>
file that specifies
the plugin directory location can replace plugins and modify the
capabilities provided by plugins, including authentication
plugins.
</p>
<p>
Files such as log files to which passwords might be written
should be protected. See
<a class="xref" href="password-logging.html" title="8.1.2.3 Passwords and Logging">
Section 8.1.2.3, “Passwords and Logging”
</a>
.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-innodb-redo-log-files-table.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="performance-schema-innodb-redo-log-files-table">
</a>
29.12.22.4 The innodb_redo_log_files Table
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045067477552">
</a>
<a class="indexterm" name="idm46045067476048">
</a>
<p>
The
<code class="literal">
innodb_redo_log_files
</code>
table contains a
row for each active
<code class="literal">
InnoDB
</code>
redo log file.
</p>
<p>
The
<code class="literal">
innodb_redo_log_files
</code>
table has the
following columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
FILE_ID
</code>
</p>
<p>
The ID of the redo log file. The value corresponds to the
redo log file number.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
FILE_NAME
</code>
</p>
<p>
The path and file name of the redo log file.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
START_LSN
</code>
</p>
<p>
The log sequence number of the first block in the redo log
file.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
END_LSN
</code>
</p>
<p>
The log sequence number after the last block in the redo
log file.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
SIZE_IN_BYTES
</code>
</p>
<p>
The size of the redo log data in the file, in bytes. Data
size is measured from the
<code class="literal">
END_LSN
</code>
to
the start
<code class="literal">
>START_LSN
</code>
. The redo log file
size on disk is slightly larger due to the file header
(2048 bytes), which is not included in the value reported
by this column.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
IS_FULL
</code>
</p>
<p>
Whether the redo log file is full. A value of 0 indicates
that free space in the file. A value of 1 indicates that
the file is full.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
CONSUMER_LEVEL
</code>
</p>
<p>
Reserved for future use.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/data-dictionary-limitations.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h2 class="title">
<a name="data-dictionary-limitations">
</a>
16.8 Data Dictionary Limitations
</h2>
</div>
</div>
</div>
<a class="indexterm" name="idm46045167499952">
</a>
<p>
This section describes temporary limitations introduced with the
MySQL data dictionary.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Manual creation of database directories under the data
directory (for example, with
<span class="command">
<strong>
mkdir
</strong>
</span>
) is
unsupported. Manually created database directories are not
recognized by the MySQL Server.
</p>
</li>
<li class="listitem">
<p>
DDL operations take longer due to writing to storage, undo
logs, and redo logs instead of
<code class="filename">
.frm
</code>
files.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/events-status-info.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="events-status-info">
</a>
27.4.5 Event Scheduler Status
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045082037888">
</a>
<a class="indexterm" name="idm46045082036384">
</a>
<a class="indexterm" name="idm46045082035312">
</a>
<p>
The Event Scheduler writes information about event execution that
terminates with an error or warning to the MySQL Server's error
log. See
<a class="xref" href="events-privileges.html" title="27.4.6 The Event Scheduler and MySQL Privileges">
Section 27.4.6, “The Event Scheduler and MySQL Privileges”
</a>
for an example.
</p>
<p>
To obtain information about the state of the Event Scheduler for
debugging and troubleshooting purposes, run
<a class="link" href="mysqladmin.html" title="6.5.2 mysqladmin — A MySQL Server Administration Program">
<span class="command">
<strong>
mysqladmin
debug
</strong>
</span>
</a>
(see
<a class="xref" href="mysqladmin.html" title="6.5.2 mysqladmin — A MySQL Server Administration Program">
Section 6.5.2, “mysqladmin — A MySQL Server Administration Program”
</a>
); after running
this command, the server's error log contains output relating to
the Event Scheduler, similar to what is shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-none"><div class="docs-select-all right" id="sa37892863"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-none">Events status:
LLA = Last Locked At LUA = Last Unlocked At
WOC = Waiting On Condition DL = Data Locked
Event scheduler status:
State : INITIALIZED
Thread id : 0
LLA : n/a:0
LUA : n/a:0
WOC : NO
Workers : 0
Executed : 0
Data locked: NO
Event queue status:
Element count : 0
Data locked : NO
Attempting lock : NO
LLA : init_queue:95
LUA : init_queue:103
WOC : NO
Next activation : never</code></pre>
</div>
<p>
In statements that occur as part of events executed by the Event
Scheduler, diagnostics messages (not only errors, but also
warnings) are written to the error log, and, on Windows, to the
application event log. For frequently executed events, it is
possible for this to result in many logged messages. For example,
for
<code class="literal">
SELECT ... INTO
<em class="replaceable">
<code>
var_list
</code>
</em>
</code>
statements, if the
query returns no rows, a warning with error code 1329 occurs
(
<code class="literal">
No data
</code>
), and the variable values remain
unchanged. If the query returns multiple rows, error 1172 occurs
(
<code class="literal">
Result consisted of more than one row
</code>
). For
either condition, you can avoid having the warnings be logged by
declaring a condition handler; see
<a class="xref" href="declare-handler.html" title="15.6.7.2 DECLARE ... HANDLER Statement">
Section 15.6.7.2, “DECLARE ... HANDLER Statement”
</a>
. For statements that may
retrieve multiple rows, another strategy is to use
<code class="literal">
LIMIT
1
</code>
to limit the result set to a single row.
</p>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/information-schema-connection-control-failed-login-attempts-table.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="information-schema-connection-control-failed-login-attempts-table">
</a>
28.6.2 The INFORMATION_SCHEMA CONNECTION_CONTROL_FAILED_LOGIN_ATTEMPTS Table
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045076002624">
</a>
<p>
This table provides information about the current number of
consecutive failed connection attempts per account (user/host
combination).
</p>
<p>
<a class="link" href="information-schema-connection-control-failed-login-attempts-table.html" title="28.6.2 The INFORMATION_SCHEMA CONNECTION_CONTROL_FAILED_LOGIN_ATTEMPTS Table">
<code class="literal">
CONNECTION_CONTROL_FAILED_LOGIN_ATTEMPTS
</code>
</a>
has these columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
USERHOST
</code>
</p>
<p>
The user/host combination indicating an account that has
failed connection attempts, in
<code class="literal">
'
<em class="replaceable">
<code>
user_name
</code>
</em>
'@'
<em class="replaceable">
<code>
host_name
</code>
</em>
'
</code>
format.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
FAILED_ATTEMPTS
</code>
</p>
<p>
The current number of consecutive failed connection attempts
for the
<code class="literal">
USERHOST
</code>
value. This counts all
failed attempts, regardless of whether they were delayed. The
number of attempts for which the server added a delay to its
response is the difference between the
<code class="literal">
FAILED_ATTEMPTS
</code>
value and the
<a class="link" href="connection-control-variables.html#sysvar_connection_control_failed_connections_threshold">
<code class="literal">
connection_control_failed_connections_threshold
</code>
</a>
system variable value.
</p>
</li>
</ul>
</div>
<h4>
<a name="idm46045075989824">
</a>
Notes
</h4>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
The
<code class="literal">
CONNECTION_CONTROL_FAILED_LOGIN_ATTEMPTS
</code>
plugin must be activated for this table to be available, and
the
<code class="literal">
CONNECTION_CONTROL
</code>
plugin must be
activated or the table contents are always empty. See
<a class="xref" href="connection-control.html" title="8.4.2 The Connection-Control Plugins">
Section 8.4.2, “The Connection-Control Plugins”
</a>
.
</p>
</li>
<li class="listitem">
<p>
The table contains rows only for accounts that have had one or
more consecutive failed connection attempts without a
subsequent successful attempt. When an account connects
successfully, its failed-connection count is reset to zero and
the server removes any row corresponding to the account.
</p>
</li>
<li class="listitem">
<p>
Assigning a value to the
<a class="link" href="connection-control-variables.html#sysvar_connection_control_failed_connections_threshold">
<code class="literal">
connection_control_failed_connections_threshold
</code>
</a>
system variable at runtime resets all accumulated
failed-connection counters to zero, which causes the table to
become empty.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/sys-statements-with-errors-or-warnings.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="sys-statements-with-errors-or-warnings">
</a>
30.4.3.36 The statements_with_errors_or_warnings and
x$statements_with_errors_or_warnings Views
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045062166208">
</a>
<a class="indexterm" name="idm46045062164752">
</a>
<a class="indexterm" name="idm46045062163248">
</a>
<a class="indexterm" name="idm46045062161728">
</a>
<p>
These views display normalized statements that have produced
errors or warnings. By default, rows are sorted by descending
error and warning counts.
</p>
<p>
The
<a class="link" href="sys-statements-with-errors-or-warnings.html" title="30.4.3.36 The statements_with_errors_or_warnings and x$statements_with_errors_or_warnings Views">
<code class="literal">
statements_with_errors_or_warnings
</code>
</a>
and
<a class="link" href="sys-statements-with-errors-or-warnings.html" title="30.4.3.36 The statements_with_errors_or_warnings and x$statements_with_errors_or_warnings Views">
<code class="literal">
x$statements_with_errors_or_warnings
</code>
</a>
views have these columns:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
query
</code>
</p>
<p>
The normalized statement string.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
db
</code>
</p>
<p>
The default database for the statement, or
<code class="literal">
NULL
</code>
if there is none.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
exec_count
</code>
</p>
<p>
The total number of times the statement has executed.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
errors
</code>
</p>
<p>
The total number of errors produced by occurrences of the
statement.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
error_pct
</code>
</p>
<p>
The percentage of statement occurrences that produced
errors.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
warnings
</code>
</p>
<p>
The total number of warnings produced by occurrences of
the statement.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
warning_pct
</code>
</p>
<p>
The percentage of statement occurrences that produced
warnings.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
first_seen
</code>
</p>
<p>
The time at which the statement was first seen.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
last_seen
</code>
</p>
<p>
The time at which the statement was most recently seen.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
digest
</code>
</p>
<p>
The statement digest.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/mysql-shell-tutorial-python-shell.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="mysql-shell-tutorial-python-shell">
</a>
22.4.1 MySQL Shell
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045127402928">
</a>
<p>
This quick-start guide assumes a certain level of familiarity with
MySQL Shell. The following section is a high level overview, see
the MySQL Shell documentation for more information. MySQL Shell
is a unified scripting interface to MySQL Server. It supports
scripting in JavaScript and Python. JavaScript is the default
processing mode.
</p>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="mysql-shell-tutorial-python-shell-start">
</a>
Start MySQL Shell
</h4>
</div>
</div>
</div>
<p>
After you have installed and started MySQL server, connect
MySQL Shell to the server instance. You need to know the
address of the MySQL server instance you plan to connect to. To
be able to use the instance as a Document Store, the server
instance must have X Plugin installed and you should connect to
the server using X Protocol. For example to connect to the
instance
<code class="literal">
ds1.example.com
</code>
on the default
X Protocol port of 33060 use the network string
<code class="literal">
<em class="replaceable">
<code>
user
</code>
</em>
@ds1.example.com:33060
</code>
.
</p>
<div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Tip
</div>
<p>
If you connect to the instance using classic MySQL protocol, for
example by using the default
<a class="link" href="server-system-variables.html#sysvar_port">
<code class="literal">
port
</code>
</a>
of 3306 instead of the
<a class="link" href="x-plugin-options-system-variables.html#sysvar_mysqlx_port">
<code class="literal">
mysqlx_port
</code>
</a>
, you
<span class="emphasis">
<em>
cannot
</em>
</span>
use the Document Store
functionality shown in this tutorial. For example the
<code class="literal">
db
</code>
global object is not populated. To use
the Document Store, always connect using X Protocol.
</p>
</div>
<p>
If MySQL Shell is not already running, open a terminal window
and issue:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa7852031"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal">mysqlsh <em class="replaceable">user</em>@ds1<span class="token punctuation">.</span>example<span class="token punctuation">.</span>com<span class="token punctuation">:</span>33060/world_x</code></pre>
</div>
<p>
Alternatively, if MySQL Shell is already running use the
<code class="literal">
\connect
</code>
command by issuing:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-mysqlsh"><div class="docs-select-all right" id="sa25159583"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-mysqlsh">\connect <em class="replaceable">user</em>@ds1<span class="token punctuation">.</span>example<span class="token punctuation">.</span>com<span class="token punctuation">:</span><span class="token number">33060</span><span class="token operator">/</span>world_x</code></pre>
</div>
<p>
You need to specify the address of the MySQL server instance
which you want to connect MySQL Shell to. For example in the
previous example:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<em class="replaceable">
<code>
user
</code>
</em>
represents the user name of
your MySQL account.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
ds1.example.com
</code>
is the hostname of the
server instance running MySQL. Replace this with the
hostname of the MySQL server instance you are using as a
Document Store.
</p>
</li>
<li class="listitem">
<p>
The default schema for this session is
<code class="literal">
world_x
</code>
. For instructions on setting up
the
<code class="literal">
world_x
</code>
schema, see
<a class="xref" href="mysql-shell-tutorial-python-download.html" title="22.4.2 Download and Import world_x Database">
Section 22.4.2, “Download and Import world_x Database”
</a>
.
</p>
</li>
</ul>
</div>
<p>
For more information, see
<a class="xref" href="connecting-using-uri-or-key-value-pairs.html" title="6.2.5 Connecting to the Server Using URI-Like Strings or Key-Value Pairs">
Section 6.2.5, “Connecting to the Server Using URI-Like Strings or Key-Value Pairs”
</a>
.
</p>
<p>
Once MySQL Shell opens, the
<code class="literal">
mysql-js>
</code>
prompt indicates that the active language for this session is
JavaScript. To switch MySQL Shell to Python mode, use the
<code class="literal">
\py
</code>
command.
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-mysqlsh"><div class="docs-select-all right" id="sa30453219"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-mysqlsh"><span class="token prompt">mysql-js></span> \py
Switching to Python mode<span class="token operator">...</span>
<span class="token prompt">mysql-py></span></code></pre>
</div>
<p>
MySQL Shell supports input-line editing as follows:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<span class="keycap">
<strong>
left-arrow
</strong>
</span>
and
<span class="keycap">
<strong>
right-arrow
</strong>
</span>
keys move horizontally within the current input line.
</p>
</li>
<li class="listitem">
<p>
<span class="keycap">
<strong>
up-arrow
</strong>
</span>
and
<span class="keycap">
<strong>
down-arrow
</strong>
</span>
keys move up and down through the set of previously entered
lines.
</p>
</li>
<li class="listitem">
<p>
<span class="keycap">
<strong>
Backspace
</strong>
</span>
deletes the character before the
cursor and typing new characters enters them at the cursor
position.
</p>
</li>
<li class="listitem">
<p>
<span class="keycap">
<strong>
Enter
</strong>
</span>
sends the current input line to the
server.
</p>
</li>
</ul>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="mysql-shell-tutorial-python-shell-help">
</a>
Get Help for MySQL Shell
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045127364816">
</a>
<p>
Type
<span class="command">
<strong>
mysqlsh --help
</strong>
</span>
at the prompt of your
command interpreter for a list of command-line options.
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa61160619"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal">mysqlsh <span class="token property">--help</span></code></pre>
</div>
<p>
Type
<code class="literal">
\help
</code>
at the MySQL Shell prompt for a
list of available commands and their descriptions.
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-mysqlsh"><div class="docs-select-all right" id="sa76179649"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-mysqlsh"><span class="token prompt">mysql-py></span> \help</code></pre>
</div>
<p>
Type
<code class="literal">
\help
</code>
followed by a command name for
detailed help about an individual MySQL Shell command. For
example, to view help on the
<code class="literal">
\connect
</code>
command, issue:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-mysqlsh"><div class="docs-select-all right" id="sa61762533"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-mysqlsh"><span class="token prompt">mysql-py></span> \help \connect</code></pre>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="mysql-shell-tutorial-python-shell-quit">
</a>
Quit MySQL Shell
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045127352800">
</a>
<p>
To quit MySQL Shell, issue the following command:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-mysqlsh"><div class="docs-select-all right" id="sa24367469"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-mysqlsh"><span class="token prompt">mysql-py></span> \quit</code></pre>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h4 class="title">
<a name="idm46045127349104">
</a>
Related Information
</h4>
</div>
</div>
</div>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
See
<a class="ulink" href="/doc/mysql-shell/8.4/en/mysql-shell-interactive-code-execution.html" target="_top">
Interactive Code Execution
</a>
for an explanation of how interactive code execution works
in MySQL Shell.
</p>
</li>
<li class="listitem">
<p>
See
<a class="ulink" href="/doc/mysql-shell/8.4/en/mysql-shell-getting-started.html" target="_top">
Getting Started with MySQL Shell
</a>
to learn
about session and connection alternatives.
</p>
</li>
</ul>
</div>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/validate-password-options-variables.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="validate-password-options-variables">
</a>
8.4.3.2 Password Validation Options and Variables
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045241725472">
</a>
<p>
This section describes the system and status variables that
<code class="literal">
validate_password
</code>
provides to enable its
operation to be configured and monitored.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="xref" href="validate-password-options-variables.html#validate-password-system-variables" title="Password Validation Component System Variables">
Password Validation Component System Variables
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="validate-password-options-variables.html#validate-password-status-variables" title="Password Validation Component Status Variables">
Password Validation Component Status Variables
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="validate-password-options-variables.html#validate-password-plugin-options" title="Password Validation Plugin Options">
Password Validation Plugin Options
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="validate-password-options-variables.html#validate-password-plugin-system-variables" title="Password Validation Plugin System Variables">
Password Validation Plugin System Variables
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="validate-password-options-variables.html#validate-password-plugin-status-variables" title="Password Validation Plugin Status Variables">
Password Validation Plugin Status Variables
</a>
</p>
</li>
</ul>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="validate-password-system-variables">
</a>
Password Validation Component System Variables
</h5>
</div>
</div>
</div>
<a class="indexterm" name="idm46045241715696">
</a>
<p>
If the
<code class="literal">
validate_password
</code>
component is
enabled, it exposes several system variables that enable
configuration of password checking:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa61836564"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SHOW</span> <span class="token keyword">VARIABLES</span> <span class="token operator">LIKE</span> <span class="token string">'validate_password.%'</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> Variable_name <span class="token punctuation">|</span> Value <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> validate_password.changed_characters_percentage <span class="token punctuation">|</span> 0 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> validate_password.check_user_name <span class="token punctuation">|</span> ON <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> validate_password.dictionary_file <span class="token punctuation">|</span> <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> validate_password.length <span class="token punctuation">|</span> 8 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> validate_password.mixed_case_count <span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> validate_password.number_count <span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> validate_password.policy <span class="token punctuation">|</span> MEDIUM <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> validate_password.special_char_count <span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
<p>
To change how passwords are checked, you can set these system
variables at server startup or at runtime. The following list
describes the meaning of each variable.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a name="sysvar_validate_password.changed_characters_percentage">
</a>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.changed_characters_percentage">
<code class="literal">
validate_password.changed_characters_percentage
</code>
</a>
</p>
<a class="indexterm" name="idm46045241707296">
</a>
<a class="indexterm" name="idm46045241706176">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate_password.changed_characters_percentage">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-password.changed-characters-percentage[=value]
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.changed_characters_percentage">
validate_password.changed_characters_percentage
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
<tr>
<th>
Maximum Value
</th>
<td>
<code class="literal">
100
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Indicates the minimum number of characters, as a
percentage of all characters, in a password that a user
must change before
<code class="literal">
validate_password
</code>
accepts a new password for the user's own account.
This applies only when changing an existing password, and
has no effect when setting a user account's initial
password.
</p>
<p>
This variable is not available unless
<code class="literal">
validate_password
</code>
is installed.
</p>
<p>
By default,
<code class="literal">
validate_password.changed_characters_percentage
</code>
permits all of the characters from the current password to
be reused in the new password. The range of valid
percentages is 0 to 100. If set to 100 percent, all of the
characters from the current password are rejected,
regardless of the casing. Characters
'
<code class="literal">
abc
</code>
' and '
<code class="literal">
ABC
</code>
' are
considered to be the same characters. If
<code class="literal">
validate_password
</code>
rejects the new
password, it reports an error indicating the minimum
number of characters that must differ.
</p>
<p>
If the
<a class="link" href="alter-user.html" title="15.7.1.1 ALTER USER Statement">
<code class="literal">
ALTER USER
</code>
</a>
statement
does not provide the existing password in a
<a class="link" href="replace.html" title="15.2.12 REPLACE Statement">
<code class="literal">
REPLACE
</code>
</a>
clause, this
variable is not enforced. Whether the
<a class="link" href="replace.html" title="15.2.12 REPLACE Statement">
<code class="literal">
REPLACE
</code>
</a>
clause is required
is subject to the password verification policy as it
applies to a given account. For an overview of the policy,
see
<a class="xref" href="password-management.html#password-reverification-policy" title="Password Verification-Required Policy">
Password Verification-Required Policy
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_validate_password.check_user_name">
</a>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.check_user_name">
<code class="literal">
validate_password.check_user_name
</code>
</a>
</p>
<a class="indexterm" name="idm46045241665232">
</a>
<a class="indexterm" name="idm46045241664192">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate_password.check_user_name">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-password.check-user-name[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.check_user_name">
validate_password.check_user_name
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
ON
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Whether
<code class="literal">
validate_password
</code>
compares
passwords to the user name part of the effective user
account for the current session and rejects them if they
match. This variable is unavailable unless
<code class="literal">
validate_password
</code>
is installed.
</p>
<p>
By default,
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.check_user_name">
<code class="literal">
validate_password.check_user_name
</code>
</a>
is enabled. This variable controls user name matching
independent of the value of
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.policy">
<code class="literal">
validate_password.policy
</code>
</a>
.
</p>
<p>
When
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.check_user_name">
<code class="literal">
validate_password.check_user_name
</code>
</a>
is enabled, it has these effects:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
Checking occurs in all contexts for which
<code class="literal">
validate_password
</code>
is invoked, which
includes use of statements such as
<a class="link" href="alter-user.html" title="15.7.1.1 ALTER USER Statement">
<code class="literal">
ALTER USER
</code>
</a>
or
<a class="link" href="set-password.html" title="15.7.1.10 SET PASSWORD Statement">
<code class="literal">
SET PASSWORD
</code>
</a>
to change
the current user's password, and invocation of
functions such as
<a class="link" href="encryption-functions.html#function_validate-password-strength">
<code class="literal">
VALIDATE_PASSWORD_STRENGTH()
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
The user names used for comparison are taken from the
values of the
<a class="link" href="information-functions.html#function_user">
<code class="literal">
USER()
</code>
</a>
and
<a class="link" href="information-functions.html#function_current-user">
<code class="literal">
CURRENT_USER()
</code>
</a>
functions for the current session. An implication is
that a user who has sufficient privileges to set
another user's password can set the password to
that user's name, and cannot set that user'
password to the name of the user executing the
statement. For example,
<code class="literal">
'root'@'localhost'
</code>
can set the
password for
<code class="literal">
'jeffrey'@'localhost'
</code>
to
<code class="literal">
'jeffrey'
</code>
, but cannot set the
password to
<code class="literal">
'root
</code>
.
</p>
</li>
<li class="listitem">
<p>
Only the user name part of the
<a class="link" href="information-functions.html#function_user">
<code class="literal">
USER()
</code>
</a>
and
<a class="link" href="information-functions.html#function_current-user">
<code class="literal">
CURRENT_USER()
</code>
</a>
function
values is used, not the host name part. If a user name
is empty, no comparison occurs.
</p>
</li>
<li class="listitem">
<p>
If a password is the same as the user name or its
reverse, a match occurs and the password is rejected.
</p>
</li>
<li class="listitem">
<p>
User-name matching is case-sensitive. The password and
user name values are compared as binary strings on a
byte-by-byte basis.
</p>
</li>
<li class="listitem">
<p>
If a password matches the user name,
<a class="link" href="encryption-functions.html#function_validate-password-strength">
<code class="literal">
VALIDATE_PASSWORD_STRENGTH()
</code>
</a>
returns 0 regardless of how other
<code class="literal">
validate_password
</code>
system variables
are set.
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
<a name="sysvar_validate_password.dictionary_file">
</a>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.dictionary_file">
<code class="literal">
validate_password.dictionary_file
</code>
</a>
</p>
<a class="indexterm" name="idm46045241611536">
</a>
<a class="indexterm" name="idm46045241610496">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate_password.dictionary_file">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-password.dictionary-file=file_name
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.dictionary_file">
validate_password.dictionary_file
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
File name
</td>
</tr>
</tbody>
</table>
</div>
<p>
The path name of the dictionary file that
<code class="literal">
validate_password
</code>
uses for checking
passwords. This variable is unavailable unless
<code class="literal">
validate_password
</code>
is installed.
</p>
<p>
By default, this variable has an empty value and
dictionary checks are not performed. For dictionary checks
to occur, the variable value must be nonempty. If the file
is named as a relative path, it is interpreted relative to
the server data directory. File contents should be
lowercase, one word per line. Contents are treated as
having a character set of
<code class="literal">
utf8mb3
</code>
. The
maximum permitted file size is 1MB.
</p>
<p>
For the dictionary file to be used during password
checking, the password policy must be set to 2
(
<code class="literal">
STRONG
</code>
); see the description of the
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.policy">
<code class="literal">
validate_password.policy
</code>
</a>
system variable. Assuming that is true, each substring of
the password of length 4 up to 100 is compared to the
words in the dictionary file. Any match causes the
password to be rejected. Comparisons are not
case-sensitive.
</p>
<p>
For
<a class="link" href="encryption-functions.html#function_validate-password-strength">
<code class="literal">
VALIDATE_PASSWORD_STRENGTH()
</code>
</a>
,
the password is checked against all policies, including
<code class="literal">
STRONG
</code>
, so the strength assessment
includes the dictionary check regardless of the
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.policy">
<code class="literal">
validate_password.policy
</code>
</a>
value.
</p>
<p>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.dictionary_file">
<code class="literal">
validate_password.dictionary_file
</code>
</a>
can be set at runtime and assigning a value causes the
named file to be read without a server restart.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_validate_password.length">
</a>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.length">
<code class="literal">
validate_password.length
</code>
</a>
</p>
<a class="indexterm" name="idm46045241576496">
</a>
<a class="indexterm" name="idm46045241575392">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate_password.length">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-password.length=#
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.length">
validate_password.length
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
8
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
The minimum number of characters that
<code class="literal">
validate_password
</code>
requires passwords to
have. This variable is unavailable unless
<code class="literal">
validate_password
</code>
is installed.
</p>
<p>
The
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.length">
<code class="literal">
validate_password.length
</code>
</a>
minimum value is a function of several other related
system variables. The value cannot be set less than the
value of this expression:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-none"><div class="docs-select-all right" id="sa73913852"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-none">validate_password.number_count
+ validate_password.special_char_count
+ (2 * validate_password.mixed_case_count)</code></pre>
</div>
<p>
If
<code class="literal">
validate_password
</code>
adjusts the value
of
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.length">
<code class="literal">
validate_password.length
</code>
</a>
due to the preceding constraint, it writes a message to
the error log.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_validate_password.mixed_case_count">
</a>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.mixed_case_count">
<code class="literal">
validate_password.mixed_case_count
</code>
</a>
</p>
<a class="indexterm" name="idm46045241541216">
</a>
<a class="indexterm" name="idm46045241540176">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate_password.mixed_case_count">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-password.mixed-case-count=#
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.mixed_case_count">
validate_password.mixed_case_count
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
1
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
The minimum number of lowercase and uppercase characters
that
<code class="literal">
validate_password
</code>
requires
passwords to have if the password policy is
<code class="literal">
MEDIUM
</code>
or stronger. This variable is
unavailable unless
<code class="literal">
validate_password
</code>
is
installed.
</p>
<p>
For a given
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.mixed_case_count">
<code class="literal">
validate_password.mixed_case_count
</code>
</a>
value, the password must have that many lowercase
characters, and that many uppercase characters.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_validate_password.number_count">
</a>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.number_count">
<code class="literal">
validate_password.number_count
</code>
</a>
</p>
<a class="indexterm" name="idm46045241508880">
</a>
<a class="indexterm" name="idm46045241507776">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate_password.number_count">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-password.number-count=#
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.number_count">
validate_password.number_count
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
1
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
The minimum number of numeric (digit) characters that
<code class="literal">
validate_password
</code>
requires passwords to
have if the password policy is
<code class="literal">
MEDIUM
</code>
or stronger. This variable is unavailable unless
<code class="literal">
validate_password
</code>
is installed.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_validate_password.policy">
</a>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.policy">
<code class="literal">
validate_password.policy
</code>
</a>
</p>
<a class="indexterm" name="idm46045241478432">
</a>
<a class="indexterm" name="idm46045241477328">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate_password.policy">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-password.policy=value
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.policy">
validate_password.policy
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Enumeration
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
1
</code>
</td>
</tr>
<tr>
<th>
Valid Values
</th>
<td>
<p class="valid-value">
<code class="literal">
0
</code>
</p>
<p class="valid-value">
<code class="literal">
1
</code>
</p>
<p class="valid-value">
<code class="literal">
2
</code>
</p>
</td>
</tr>
</tbody>
</table>
</div>
<p>
The password policy enforced by
<code class="literal">
validate_password
</code>
. This variable is
unavailable unless
<code class="literal">
validate_password
</code>
is
installed.
</p>
<p>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.policy">
<code class="literal">
validate_password.policy
</code>
</a>
affects how
<code class="literal">
validate_password
</code>
uses its
other policy-setting system variables, except for checking
passwords against user names, which is controlled
independently by
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.check_user_name">
<code class="literal">
validate_password.check_user_name
</code>
</a>
.
</p>
<p>
The
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.policy">
<code class="literal">
validate_password.policy
</code>
</a>
value can be specified using numeric values 0, 1, 2, or
the corresponding symbolic values
<code class="literal">
LOW
</code>
,
<code class="literal">
MEDIUM
</code>
,
<code class="literal">
STRONG
</code>
. The
following table describes the tests performed for each
policy. For the length test, the required length is the
value of the
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.length">
<code class="literal">
validate_password.length
</code>
</a>
system variable. Similarly, the required values for the
other tests are given by other
<code class="literal">
validate_password.
<em class="replaceable">
<code>
xxx
</code>
</em>
</code>
variables.
</p>
<div class="informaltable">
<table summary="Password policies enforced by the validate_password component and the tests performed for each policy.">
<colgroup>
<col style="width: 20%"/>
<col style="width: 80%"/>
</colgroup>
<thead>
<tr>
<th>
Policy
</th>
<th>
Tests Performed
</th>
</tr>
</thead>
<tbody>
<tr>
<td>
<code class="literal">
0
</code>
or
<code class="literal">
LOW
</code>
</td>
<td>
Length
</td>
</tr>
<tr>
<td>
<code class="literal">
1
</code>
or
<code class="literal">
MEDIUM
</code>
</td>
<td>
Length; numeric, lowercase/uppercase, and special characters
</td>
</tr>
<tr>
<td>
<code class="literal">
2
</code>
or
<code class="literal">
STRONG
</code>
</td>
<td>
Length; numeric, lowercase/uppercase, and special characters; dictionary
file
</td>
</tr>
</tbody>
</table>
</div>
</li>
<li class="listitem">
<p>
<a name="sysvar_validate_password.special_char_count">
</a>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.special_char_count">
<code class="literal">
validate_password.special_char_count
</code>
</a>
</p>
<a class="indexterm" name="idm46045241420960">
</a>
<a class="indexterm" name="idm46045241419920">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate_password.special_char_count">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-password.special-char-count=#
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.special_char_count">
validate_password.special_char_count
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
1
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
The minimum number of nonalphanumeric characters that
<code class="literal">
validate_password
</code>
requires passwords to
have if the password policy is
<code class="literal">
MEDIUM
</code>
or stronger. This variable is unavailable unless
<code class="literal">
validate_password
</code>
is installed.
</p>
</li>
</ul>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="validate-password-status-variables">
</a>
Password Validation Component Status Variables
</h5>
</div>
</div>
</div>
<a class="indexterm" name="idm46045241391408">
</a>
<p>
If the
<code class="literal">
validate_password
</code>
component is
enabled, it exposes status variables that provide operational
information:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa69011421"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SHOW</span> <span class="token keyword">STATUS</span> <span class="token operator">LIKE</span> <span class="token string">'validate_password.%'</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> Variable_name <span class="token punctuation">|</span> Value <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> validate_password.dictionary_file_last_parsed <span class="token punctuation">|</span> 2019<span class="token punctuation">-</span>10<span class="token punctuation">-</span>03 08:33:49 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> validate_password.dictionary_file_words_count <span class="token punctuation">|</span> 1902 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
<p>
The following list describes the meaning of each status
variable.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a name="statvar_validate_password.dictionary_file_last_parsed">
</a>
<a class="link" href="validate-password-options-variables.html#statvar_validate_password.dictionary_file_last_parsed">
<code class="literal">
validate_password.dictionary_file_last_parsed
</code>
</a>
</p>
<a class="indexterm" name="idm46045241383520">
</a>
<a class="indexterm" name="idm46045241382400">
</a>
<p>
When the dictionary file was last parsed. This variable is
unavailable unless
<code class="literal">
validate_password
</code>
is
installed.
</p>
</li>
<li class="listitem">
<p>
<a name="statvar_validate_password.dictionary_file_words_count">
</a>
<a class="link" href="validate-password-options-variables.html#statvar_validate_password.dictionary_file_words_count">
<code class="literal">
validate_password.dictionary_file_words_count
</code>
</a>
</p>
<a class="indexterm" name="idm46045241377120">
</a>
<a class="indexterm" name="idm46045241376000">
</a>
<p>
The number of words read from the dictionary file. This
variable is unavailable unless
<code class="literal">
validate_password
</code>
is installed.
</p>
</li>
</ul>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="validate-password-plugin-options">
</a>
Password Validation Plugin Options
</h5>
</div>
</div>
</div>
<a class="indexterm" name="idm46045241371680">
</a>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
In MySQL 8.4, the
<code class="literal">
validate_password
</code>
plugin was
reimplemented as the
<code class="literal">
validate_password
</code>
component. The
<code class="literal">
validate_password
</code>
plugin
is deprecated; expect it to be removed in a future version
of MySQL. Consequently, its options are also deprecated, and
you should expect them to be removed as well. MySQL
installations that use the plugin should make the transition
to using the component instead. See
<a class="xref" href="validate-password-transitioning.html" title="8.4.3.3 Transitioning to the Password Validation Component">
Section 8.4.3.3, “Transitioning to the Password Validation Component”
</a>
.
</p>
</div>
<p>
To control activation of the
<code class="literal">
validate_password
</code>
plugin, use this option:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a name="option_mysqld_validate-password">
</a>
<a class="link" href="validate-password-options-variables.html#option_mysqld_validate-password">
<code class="option">
--validate-password[=
<em class="replaceable">
<code>
value
</code>
</em>
]
</code>
</a>
</p>
<a class="indexterm" name="idm46045241362128">
</a>
<a class="indexterm" name="idm46045241360672">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate-password">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-password[=value]
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Enumeration
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
ON
</code>
</td>
</tr>
<tr>
<th>
Valid Values
</th>
<td>
<p class="valid-value">
<code class="literal">
ON
</code>
</p>
<p class="valid-value">
<code class="literal">
OFF
</code>
</p>
<p class="valid-value">
<code class="literal">
FORCE
</code>
</p>
<p class="valid-value">
<code class="literal">
FORCE_PLUS_PERMANENT
</code>
</p>
</td>
</tr>
</tbody>
</table>
</div>
<p>
This option controls how the server loads the deprecated
<code class="literal">
validate_password
</code>
plugin at startup.
The value should be one of those available for
plugin-loading options, as described in
<a class="xref" href="plugin-loading.html" title="7.6.1 Installing and Uninstalling Plugins">
Section 7.6.1, “Installing and Uninstalling Plugins”
</a>
. For example,
<a class="link" href="validate-password-options-variables.html#option_mysqld_validate-password">
<code class="option">
--validate-password=FORCE_PLUS_PERMANENT
</code>
</a>
tells the server to load the plugin at startup and
prevents it from being removed while the server is
running.
</p>
<p>
This option is available only if the
<code class="literal">
validate_password
</code>
plugin has been
previously registered with
<a class="link" href="install-plugin.html" title="15.7.4.4 INSTALL PLUGIN Statement">
<code class="literal">
INSTALL
PLUGIN
</code>
</a>
or is loaded with
<a class="link" href="server-options.html#option_mysqld_plugin-load-add">
<code class="option">
--plugin-load-add
</code>
</a>
. See
<a class="xref" href="validate-password-installation.html" title="8.4.3.1 Password Validation Component Installation and Uninstallation">
Section 8.4.3.1, “Password Validation Component Installation and Uninstallation”
</a>
.
</p>
</li>
</ul>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="validate-password-plugin-system-variables">
</a>
Password Validation Plugin System Variables
</h5>
</div>
</div>
</div>
<a class="indexterm" name="idm46045241334368">
</a>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
In MySQL 8.4, the
<code class="literal">
validate_password
</code>
plugin was
reimplemented as the
<code class="literal">
validate_password
</code>
component. The
<code class="literal">
validate_password
</code>
plugin
is deprecated; expect it to be removed in a future version
of MySQL. Consequently, its system variables are also
deprecated and you should expect them to be removed as well.
Use the corresponding system variables of the
<code class="literal">
validate_password
</code>
component instead; see
<a class="xref" href="validate-password-options-variables.html#validate-password-system-variables" title="Password Validation Component System Variables">
Password Validation Component System Variables
</a>
. MySQL
installations that use the plugin should make the transition
to using the component instead. See
<a class="xref" href="validate-password-transitioning.html" title="8.4.3.3 Transitioning to the Password Validation Component">
Section 8.4.3.3, “Transitioning to the Password Validation Component”
</a>
.
</p>
</div>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a name="sysvar_validate_password_check_user_name">
</a>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_check_user_name">
<code class="literal">
validate_password_check_user_name
</code>
</a>
</p>
<a class="indexterm" name="idm46045241324592">
</a>
<a class="indexterm" name="idm46045241323552">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate_password_check_user_name">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-password-check-user-name[={OFF|ON}]
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_check_user_name">
validate_password_check_user_name
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Boolean
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
ON
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
This
<code class="literal">
validate_password
</code>
plugin system
variable is deprecated; expect it to be removed in a
future version of MySQL. Use the corresponding
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.check_user_name">
<code class="literal">
validate_password.check_user_name
</code>
</a>
system variable of the
<code class="literal">
validate_password
</code>
component instead.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_validate_password_dictionary_file">
</a>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_dictionary_file">
<code class="literal">
validate_password_dictionary_file
</code>
</a>
</p>
<a class="indexterm" name="idm46045241295856">
</a>
<a class="indexterm" name="idm46045241294816">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate_password_dictionary_file">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-password-dictionary-file=file_name
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_dictionary_file">
validate_password_dictionary_file
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
File name
</td>
</tr>
</tbody>
</table>
</div>
<p>
This
<code class="literal">
validate_password
</code>
plugin system
variable is deprecated; expect it to be removed in a
future version of MySQL. Use the corresponding
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.dictionary_file">
<code class="literal">
validate_password.dictionary_file
</code>
</a>
system variable of the
<code class="literal">
validate_password
</code>
component instead.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_validate_password_length">
</a>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_length">
<code class="literal">
validate_password_length
</code>
</a>
</p>
<a class="indexterm" name="idm46045241269664">
</a>
<a class="indexterm" name="idm46045241268560">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate_password_length">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-password-length=#
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_length">
validate_password_length
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
8
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
This
<code class="literal">
validate_password
</code>
plugin system
variable is deprecated; expect it to be removed in a
future version of MySQL. Use the corresponding
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.length">
<code class="literal">
validate_password.length
</code>
</a>
system variable of the
<code class="literal">
validate_password
</code>
component instead.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_validate_password_mixed_case_count">
</a>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_mixed_case_count">
<code class="literal">
validate_password_mixed_case_count
</code>
</a>
</p>
<a class="indexterm" name="idm46045241238608">
</a>
<a class="indexterm" name="idm46045241237568">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate_password_mixed_case_count">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-password-mixed-case-count=#
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_mixed_case_count">
validate_password_mixed_case_count
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
1
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
This
<code class="literal">
validate_password
</code>
plugin system
variable is deprecated; expect it to be removed in a
future version of MySQL. Use the corresponding
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.mixed_case_count">
<code class="literal">
validate_password.mixed_case_count
</code>
</a>
system variable of the
<code class="literal">
validate_password
</code>
component instead.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_validate_password_number_count">
</a>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_number_count">
<code class="literal">
validate_password_number_count
</code>
</a>
</p>
<a class="indexterm" name="idm46045241207600">
</a>
<a class="indexterm" name="idm46045241206496">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate_password_number_count">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-password-number-count=#
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_number_count">
validate_password_number_count
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
1
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
This
<code class="literal">
validate_password
</code>
plugin system
variable is deprecated; expect it to be removed in a
future version of MySQL. Use the corresponding
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.number_count">
<code class="literal">
validate_password.number_count
</code>
</a>
system variable of the
<code class="literal">
validate_password
</code>
component instead.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_validate_password_policy">
</a>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_policy">
<code class="literal">
validate_password_policy
</code>
</a>
</p>
<a class="indexterm" name="idm46045241176656">
</a>
<a class="indexterm" name="idm46045241175552">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate_password_policy">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-password-policy=value
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_policy">
validate_password_policy
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Enumeration
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
1
</code>
</td>
</tr>
<tr>
<th>
Valid Values
</th>
<td>
<p class="valid-value">
<code class="literal">
0
</code>
</p>
<p class="valid-value">
<code class="literal">
1
</code>
</p>
<p class="valid-value">
<code class="literal">
2
</code>
</p>
</td>
</tr>
</tbody>
</table>
</div>
<p>
This
<code class="literal">
validate_password
</code>
plugin system
variable is deprecated; expect it to be removed in a
future version of MySQL. Use the corresponding
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.policy">
<code class="literal">
validate_password.policy
</code>
</a>
system variable of the
<code class="literal">
validate_password
</code>
component instead.
</p>
</li>
<li class="listitem">
<p>
<a name="sysvar_validate_password_special_char_count">
</a>
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_special_char_count">
<code class="literal">
validate_password_special_char_count
</code>
</a>
</p>
<a class="indexterm" name="idm46045241143280">
</a>
<a class="indexterm" name="idm46045241142240">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for validate_password_special_char_count">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--validate-password-special-char-count=#
</code>
</td>
</tr>
<tr>
<th>
System Variable
</th>
<td>
<code class="literal">
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password_special_char_count">
validate_password_special_char_count
</a>
</code>
</td>
</tr>
<tr>
<th>
Scope
</th>
<td>
Global
</td>
</tr>
<tr>
<th>
Dynamic
</th>
<td>
Yes
</td>
</tr>
<tr>
<th>
<a class="link" href="optimizer-hints.html#optimizer-hints-set-var" title="Variable-Setting Hint Syntax">
<code class="literal">
SET_VAR
</code>
</a>
Hint Applies
</th>
<td>
No
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
1
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
This
<code class="literal">
validate_password
</code>
plugin system
variable is deprecated; expect it to be removed in a
future version of MySQL. Use the corresponding
<a class="link" href="validate-password-options-variables.html#sysvar_validate_password.special_char_count">
<code class="literal">
validate_password.special_char_count
</code>
</a>
system variable of the
<code class="literal">
validate_password
</code>
component instead.
</p>
</li>
</ul>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h5 class="title">
<a name="validate-password-plugin-status-variables">
</a>
Password Validation Plugin Status Variables
</h5>
</div>
</div>
</div>
<a class="indexterm" name="idm46045241113152">
</a>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Note
</div>
<p>
In MySQL 8.4, the
<code class="literal">
validate_password
</code>
plugin was
reimplemented as the
<code class="literal">
validate_password
</code>
component. The
<code class="literal">
validate_password
</code>
plugin
is deprecated; expect it to be removed in a future version
of MySQL. Consequently, its status variables are also
deprecated; expect it to be removed. Use the corresponding
status variables of the
<code class="literal">
validate_password
</code>
component; see
<a class="xref" href="validate-password-options-variables.html#validate-password-status-variables" title="Password Validation Component Status Variables">
Password Validation Component Status Variables
</a>
. MySQL
installations that use the plugin should make the transition
to using the component instead. See
<a class="xref" href="validate-password-transitioning.html" title="8.4.3.3 Transitioning to the Password Validation Component">
Section 8.4.3.3, “Transitioning to the Password Validation Component”
</a>
.
</p>
</div>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a name="statvar_validate_password_dictionary_file_last_parsed">
</a>
<a class="link" href="validate-password-options-variables.html#statvar_validate_password_dictionary_file_last_parsed">
<code class="literal">
validate_password_dictionary_file_last_parsed
</code>
</a>
</p>
<a class="indexterm" name="idm46045241103456">
</a>
<a class="indexterm" name="idm46045241102336">
</a>
<p>
This
<code class="literal">
validate_password
</code>
plugin status
variable is deprecated; expect it to be removed in a
future version of MySQL. Use the corresponding
<a class="link" href="validate-password-options-variables.html#statvar_validate_password.dictionary_file_last_parsed">
<code class="literal">
validate_password.dictionary_file_last_parsed
</code>
</a>
status variable of the
<code class="literal">
validate_password
</code>
component instead.
</p>
</li>
<li class="listitem">
<p>
<a name="statvar_validate_password_dictionary_file_words_count">
</a>
<a class="link" href="validate-password-options-variables.html#statvar_validate_password_dictionary_file_words_count">
<code class="literal">
validate_password_dictionary_file_words_count
</code>
</a>
</p>
<a class="indexterm" name="idm46045241094880">
</a>
<a class="indexterm" name="idm46045241093760">
</a>
<p>
This
<code class="literal">
validate_password
</code>
plugin status
variable is deprecated; expect it to be removed in a
future version of MySQL. Use the corresponding
<a class="link" href="validate-password-options-variables.html#statvar_validate_password.dictionary_file_words_count">
<code class="literal">
validate_password.dictionary_file_words_count
</code>
</a>
status variable of the
<code class="literal">
validate_password
</code>
component instead.
</p>
</li>
</ul>
</div>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-programs-ndb-sign-keys.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h3 class="title">
<a name="mysql-cluster-programs-ndb-sign-keys">
</a>
25.5.28 ndb_sign_keys — Create, Sign, and Manage TLS Keys and Certificates for NDB
Cluster
</h3>
</div>
</div>
</div>
<a class="indexterm" name="idm46045096742736">
</a>
<p>
Management of TLS keys and certificates in implemented in NDB
Cluster as the executable utility program
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html" title="25.5.28 ndb_sign_keys — Create, Sign, and Manage TLS Keys and Certificates for NDB Cluster">
<span class="command">
<strong>
ndb_sign_keys
</strong>
</span>
</a>
, which can normally be found in
the MySQL
<code class="filename">
bin
</code>
directory. The program
performs such functions as creating, signing, and retiring keys
and certificates, and normally works as follows:
</p>
<div class="orderedlist">
<ol class="orderedlist" type="1">
<li class="listitem">
<p>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html" title="25.5.28 ndb_sign_keys — Create, Sign, and Manage TLS Keys and Certificates for NDB Cluster">
<span class="command">
<strong>
ndb_sign_keys
</strong>
</span>
</a>
connects to
<a class="link" href="mysql-cluster-programs-ndb-mgmd.html" title="25.5.4 ndb_mgmd — The NDB Cluster Management Server Daemon">
<span class="command">
<strong>
ndb_mgmd
</strong>
</span>
</a>
and fetches the cluster'
configuration.
</p>
</li>
<li class="listitem">
<p>
For each cluster node that is configured to run on the local
machine,
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html" title="25.5.28 ndb_sign_keys — Create, Sign, and Manage TLS Keys and Certificates for NDB Cluster">
<span class="command">
<strong>
ndb_sign_keys
</strong>
</span>
</a>
finds the
node' private key and sign it, creating an active node
certificate.
</p>
</li>
</ol>
</div>
<p>
Some additional tasks that can be performed by
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html" title="25.5.28 ndb_sign_keys — Create, Sign, and Manage TLS Keys and Certificates for NDB Cluster">
<span class="command">
<strong>
ndb_sign_keys
</strong>
</span>
</a>
are listed here:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Obtaining configuration information from a config.ini file
rather than a running
<a class="link" href="mysql-cluster-programs-ndb-mgmd.html" title="25.5.4 ndb_mgmd — The NDB Cluster Management Server Daemon">
<span class="command">
<strong>
ndb_mgmd
</strong>
</span>
</a>
</p>
</li>
<li class="listitem">
<p>
Creating the cluster' certificate authority (CA) if it
does not yet exist
</p>
</li>
<li class="listitem">
<p>
Creating private keys
</p>
</li>
<li class="listitem">
<p>
Saving keys and certificates as pending rather than active
</p>
</li>
<li class="listitem">
<p>
Signing the key for a single node as specified using
command-line options described later in this section
</p>
</li>
<li class="listitem">
<p>
Requesting a CA located on a remote host to sign a local key
</p>
</li>
</ul>
</div>
<p>
Options that can be used with
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html" title="25.5.28 ndb_sign_keys — Create, Sign, and Manage TLS Keys and Certificates for NDB Cluster">
<span class="command">
<strong>
ndb_sign_keys
</strong>
</span>
</a>
are shown in the following table. Additional descriptions follow
the table.
</p>
<p>
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_bind-host">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_bind-host">
<code class="option">
--bind-host
</code>
</a>
</p>
<a class="indexterm" name="idm46045096719008">
</a>
<a class="indexterm" name="idm46045096717520">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for bind-host">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--bind-host=host
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
mgmd, api
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Create a certificate bound to a hostname list of node types
that should have certificate hostname bindings, from the set
<code class="literal">
(mgmd,db,api)
</code>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_bound-hostname">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_bound-hostname">
<code class="option">
--bound-hostname
</code>
</a>
</p>
<a class="indexterm" name="idm46045096702496">
</a>
<a class="indexterm" name="idm46045096701008">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for bound-hostname">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--bound-hostname=hostname
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Create a certificate bound to the hostname passed to this
option.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_CA-cert">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_CA-cert">
<code class="option">
--CA-cert
</code>
</a>
</p>
<a class="indexterm" name="idm46045096686688">
</a>
<a class="indexterm" name="idm46045096685200">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for CA-cert">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--CA-cert=name
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
File name
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
NDB-Cluster-cert
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Use the name passed to this option for the CA Certificate
file.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_CA-days">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_CA-days">
<code class="option">
--CA-days
</code>
</a>
</p>
<a class="indexterm" name="idm46045096670912">
</a>
<a class="indexterm" name="idm46045096669424">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for CA-days">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--CA-days=#
</code>
</td>
</tr>
<tr>
<th>
Introduced
</th>
<td>
8.4.1
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
1461
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
-1
</code>
</td>
</tr>
<tr>
<th>
Maximum Value
</th>
<td>
<code class="literal">
2147483647
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Set the lifetime of the certificate to this many days. The
default is equivalent to 4 years plus 1 day.
<code class="literal">
-1
</code>
means the certificate never expires.
</p>
<p>
This option was added in NDB 8.4.1.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_CA-key">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_CA-key">
<code class="option">
--CA-key
</code>
</a>
</p>
<a class="indexterm" name="idm46045096646928">
</a>
<a class="indexterm" name="idm46045096645440">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for CA-key">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--CA-key=name
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
File name
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
NDB-Cluster-private-key
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Use the name passed to this option for the CA private key
file.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_CA-ordinal">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_CA-ordinal">
<code class="option">
--CA-ordinal
</code>
</a>
</p>
<a class="indexterm" name="idm46045096631152">
</a>
<a class="indexterm" name="idm46045096629664">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for CA-ordinal">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--CA-ordinal=name
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
<tr>
<th>
Valid Values
</th>
<td>
<p class="valid-value">
<code class="literal">
First
</code>
</p>
<p class="valid-value">
<code class="literal">
Second
</code>
</p>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Set the ordinal CA name; defaults to
<code class="literal">
First
</code>
for
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_create-CA">
<code class="option">
--create-CA
</code>
</a>
and
<code class="literal">
Second
</code>
for
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_rotate-CA">
<code class="option">
--rotate-CA
</code>
</a>
. The
Common Name in the CA certificate is
<span class="quote">
“
<span class="quote">
MySQL NDB
Cluster
<em class="replaceable">
<code>
ordinal
</code>
</em>
Certificate
</span>
”
</span>
, where
<em class="replaceable">
<code>
ordinal
</code>
</em>
is the ordinal name
passed to this option.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_CA-search-path">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_CA-search-path">
<code class="option">
--CA-search-path
</code>
</a>
</p>
<a class="indexterm" name="idm46045096606416">
</a>
<a class="indexterm" name="idm46045096604928">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for CA-search-path">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--CA-search-path=name
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
File name
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Specify a list of directories to search for a CA file. On
Unix platforms, the directory names are separated by colons
(
<code class="literal">
:
</code>
); on Windows systems, the semicolon
character (
<code class="literal">
;
</code>
) is used as the separator. A
directory reference may be relative or absolute; it may
contain one or more environment variables, each denoted by a
prefixed dollar sign (
<code class="literal">
$
</code>
), and expanded
prior to use.
</p>
<p>
Searching begins with the leftmost named directory and
proceeds from left to right until a file is found. An empty
string denotes an empty search path, which causes all
searches to fail. A string consisting of a single dot
(
<code class="literal">
.
</code>
) indicates that the search path is
limited to the current working directory.
</p>
<p>
If no search path is supplied, the compiled-in default value
is used. This value depends on the platform used: On
Windows, this is
<code class="literal">
$HOMEPATH\ndb-tls
</code>
; on
other platforms (including Linux), it is
<code class="literal">
$HOME/ndb-tls
</code>
. This default can be
overridden by compiling NDB Cluster using
<a class="link" href="source-configuration-options.html#option_cmake_with_ndb_tls_search_path">
<code class="option">
-DWITH_NDB_TLS_SEARCH_PATH
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_CA-tool">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_CA-tool">
<code class="option">
--CA-tool
</code>
</a>
</p>
<a class="indexterm" name="idm46045096583552">
</a>
<a class="indexterm" name="idm46045096582064">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for CA-tool">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--CA-tool=name
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
File name
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Designate an executable helper tool, including the path.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_check">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_check">
<code class="option">
--check
</code>
</a>
</p>
<a class="indexterm" name="idm46045096567840">
</a>
<a class="indexterm" name="idm46045096566352">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for check">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--check
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Check certificate expiry dates.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_config-file">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_config-file">
<code class="option">
--config-file
</code>
</a>
</p>
<a class="indexterm" name="idm46045096556544">
</a>
<a class="indexterm" name="idm46045096555056">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for config-file">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--config-file=file
</code>
</td>
</tr>
<tr>
<th>
Disabled by
</th>
<td>
<code class="literal">
no-config
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
File name
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Supply the path to the cluster configuration file (usually
<code class="filename">
config.ini
</code>
).
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_connect-retries">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_connect-retries">
<code class="option">
--connect-retries
</code>
</a>
</p>
<a class="indexterm" name="idm46045096537536">
</a>
<a class="indexterm" name="idm46045096536048">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for connect-retries">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--connect-retries=#
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
12
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
-1
</code>
</td>
</tr>
<tr>
<th>
Maximum Value
</th>
<td>
<code class="literal">
12
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Set the number of times that
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html" title="25.5.28 ndb_sign_keys — Create, Sign, and Manage TLS Keys and Certificates for NDB Cluster">
<span class="command">
<strong>
ndb_sign_keys
</strong>
</span>
</a>
attempts to connect to the
cluster. If you use
<code class="literal">
-1
</code>
, the program keeps
trying to connect until it succeeds or is forced to stop.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_connect-retry-delay">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_connect-retry-delay">
<code class="option">
--connect-retry-delay
</code>
</a>
</p>
<a class="indexterm" name="idm46045096514896">
</a>
<a class="indexterm" name="idm46045096513392">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for connect-retry-delay">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--connect-retry-delay=#
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
5
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
<tr>
<th>
Maximum Value
</th>
<td>
<code class="literal">
5
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Set the number of seconds after a failed connection attempt
which
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html" title="25.5.28 ndb_sign_keys — Create, Sign, and Manage TLS Keys and Certificates for NDB Cluster">
<span class="command">
<strong>
ndb_sign_keys
</strong>
</span>
</a>
waits before trying
again, up to the number of times determined by
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_connect-retries">
<code class="option">
--connect-retries
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_create-CA">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_create-CA">
<code class="option">
--create-CA
</code>
</a>
</p>
<a class="indexterm" name="idm46045096492128">
</a>
<a class="indexterm" name="idm46045096490640">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for create-CA">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--create-CA
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Create the CA key and certificate.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_create-key">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_create-key">
<code class="option">
--create-key
</code>
</a>
</p>
<a class="indexterm" name="idm46045096480976">
</a>
<a class="indexterm" name="idm46045096479488">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for create-key">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--create-key
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Create or replace private keys.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_curve">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_curve">
<code class="option">
--curve
</code>
</a>
</p>
<a class="indexterm" name="idm46045096469664">
</a>
<a class="indexterm" name="idm46045096468176">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for curve">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--curve=name
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
P-256
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Use the named curve for encrypting node keys.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_defaults-extra-file">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_defaults-extra-file">
<code class="option">
--defaults-extra-file
</code>
</a>
</p>
<a class="indexterm" name="idm46045096453840">
</a>
<a class="indexterm" name="idm46045096452336">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for defaults-extra-file">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--defaults-extra-file=path
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Read this option file after the global files are read.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_defaults-file">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_defaults-file">
<code class="option">
--defaults-file
</code>
</a>
</p>
<a class="indexterm" name="idm46045096438096">
</a>
<a class="indexterm" name="idm46045096436608">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for defaults-file">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--defaults-file=path
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Read this option file only.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_defaults-group-suffix">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_defaults-group-suffix">
<code class="option">
--defaults-group-suffix
</code>
</a>
</p>
<a class="indexterm" name="idm46045096422272">
</a>
<a class="indexterm" name="idm46045096420768">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for defaults-group-suffix">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--defaults-group-suffix=string
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Read not only the usual option groups, but also groups with
the usual names and a suffix of
<em class="replaceable">
<code>
string
</code>
</em>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_duration">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_duration">
<code class="option">
--duration
</code>
</a>
</p>
<a class="indexterm" name="idm46045096406032">
</a>
<a class="indexterm" name="idm46045096404544">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for duration">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--duration=#
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
-500000
</code>
</td>
</tr>
<tr>
<th>
Maximum Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
<tr>
<th>
Unit
</th>
<td>
seconds
</td>
</tr>
</tbody>
</table>
</div>
<p>
Set the lifetime of certificates or signing requests, in
seconds.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_help">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_help">
<code class="option">
--help
</code>
</a>
</p>
<a class="indexterm" name="idm46045096383376">
</a>
<a class="indexterm" name="idm46045096381888">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for help">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--help
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Print help text and exit.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_keys-to-dir">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_keys-to-dir">
<code class="option">
--keys-to-dir
</code>
</a>
</p>
<a class="indexterm" name="idm46045096372144">
</a>
<a class="indexterm" name="idm46045096370656">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for keys-to-dir">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--keys-to-dir=dirname
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Directory name
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Specify output directory for private keys (only); for this
purpose, it overrides any value set for
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_to-dir">
<code class="option">
--to-dir
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_login-path">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_login-path">
<code class="option">
--login-path
</code>
</a>
</p>
<a class="indexterm" name="idm46045096355200">
</a>
<a class="indexterm" name="idm46045096353712">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for login-path">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--login-path=path
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Read this path from the login file.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_ndb-connectstring">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_ndb-connectstring">
<code class="option">
--ndb-connectstring
</code>
</a>
</p>
<a class="indexterm" name="idm46045096339440">
</a>
<a class="indexterm" name="idm46045096337984">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for ndb-connectstring">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--ndb-connectstring=connection_string
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Set the connection string to use for connecting to
<a class="link" href="mysql-cluster-programs-ndb-mgmd.html" title="25.5.4 ndb_mgmd — The NDB Cluster Management Server Daemon">
<span class="command">
<strong>
ndb_mgmd
</strong>
</span>
</a>
, using the syntax
<code class="literal">
[nodeid=
<em class="replaceable">
<code>
id
</code>
</em>
;][host=]
<em class="replaceable">
<code>
hostname
</code>
</em>
[:
<em class="replaceable">
<code>
port
</code>
</em>
]
</code>
.
If this option is set, it overrides the value set for
<code class="literal">
NDB_CONNECTSTRING
</code>
(if any), as well as
any value set in a
<code class="filename">
my.cnf
</code>
. file.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_ndb-mgm-tls">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_ndb-mgm-tls">
<code class="option">
--ndb-mgm-tls
</code>
</a>
</p>
<a class="indexterm" name="idm46045096318832">
</a>
<a class="indexterm" name="idm46045096317344">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for ndb-mgm-tls">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--ndb-mgm-tls=level
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Enumeration
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
relaxed
</code>
</td>
</tr>
<tr>
<th>
Valid Values
</th>
<td>
<p class="valid-value">
<code class="literal">
relaxed
</code>
</p>
<p class="valid-value">
<code class="literal">
strict
</code>
</p>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Sets the level of TLS support required for the
<a class="link" href="mysql-cluster-programs-ndb-mgm.html" title="25.5.5 ndb_mgm — The NDB Cluster Management Client">
<span class="command">
<strong>
ndb_mgm
</strong>
</span>
</a>
client; one of
<code class="literal">
relaxed
</code>
or
<code class="literal">
strict
</code>
.
<code class="literal">
relaxed
</code>
(the default) means that a TLS
connection is attempted, but success is not required;
<code class="literal">
strict
</code>
means that TLS is required to
connect.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_ndb-tls-search-path">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_ndb-tls-search-path">
<code class="option">
--ndb-tls-search-path
</code>
</a>
</p>
<a class="indexterm" name="idm46045096294928">
</a>
<a class="indexterm" name="idm46045096293424">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for ndb-tls-search-path">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--ndb-tls-search-path=list
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Path name
</td>
</tr>
<tr>
<th>
Default Value (Unix)
</th>
<td>
<code class="literal">
$HOME/ndb-tls
</code>
</td>
</tr>
<tr>
<th>
Default Value (Windows)
</th>
<td>
<code class="literal">
$HOMEDIR/ndb-tls
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Specify a list of directories containing TLS keys and
certificates.
</p>
<p>
For syntax, see the description of the
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_CA-search-path">
<code class="option">
--CA-search-path
</code>
</a>
option.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_no-config">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_no-config">
<code class="option">
--no-config
</code>
</a>
</p>
<a class="indexterm" name="idm46045096275248">
</a>
<a class="indexterm" name="idm46045096273760">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for no-config">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--no-config
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Do not obtain the cluster configuration; create a single
certificate based on the options supplied (including
defaults for those not specified).
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_no-defaults">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_no-defaults">
<code class="option">
--no-defaults
</code>
</a>
</p>
<a class="indexterm" name="idm46045096263920">
</a>
<a class="indexterm" name="idm46045096262432">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for no-defaults">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--no-defaults
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Do not read default options from any option file other than
the login file.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_no-login-paths">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_no-login-paths">
<code class="option">
--no-login-paths
</code>
</a>
</p>
<a class="indexterm" name="idm46045096252672">
</a>
<a class="indexterm" name="idm46045096251184">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for no-login-paths">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--no-login-paths
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Do not read login paths from the login path file.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_passphrase">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_passphrase">
<code class="option">
--passphrase
</code>
</a>
</p>
<a class="indexterm" name="idm46045096241456">
</a>
<a class="indexterm" name="idm46045096239968">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for passphrase">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--passphrase=phrase
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Specify a CA key pass phrase.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_node-id">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_node-id">
<code class="option">
--node-id
</code>
</a>
</p>
<a class="indexterm" name="idm46045096225776">
</a>
<a class="indexterm" name="idm46045096224288">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for node-id">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--node-id=#
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
0
</code>
</td>
</tr>
<tr>
<th>
Maximum Value
</th>
<td>
<code class="literal">
255
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Create or sign a key for the node having the specified node
ID.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_node-type">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_node-type">
<code class="option">
--node-type
</code>
</a>
</p>
<a class="indexterm" name="idm46045096205200">
</a>
<a class="indexterm" name="idm46045096203712">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for node-type">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--node-type=set
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Set
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
mgmd,db,api
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Create or sign keys for the specified type or types from the
set
<code class="literal">
(mgmd,db,api)
</code>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_pending">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_pending">
<code class="option">
--pending
</code>
</a>
</p>
<a class="indexterm" name="idm46045096188656">
</a>
<a class="indexterm" name="idm46045096187168">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for pending">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--pending
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Save keys and certificates as pending, rather than active.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_print-defaults">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_print-defaults">
<code class="option">
--print-defaults
</code>
</a>
</p>
<a class="indexterm" name="idm46045096177456">
</a>
<a class="indexterm" name="idm46045096175968">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for print-defaults">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--print-defaults
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Print the program argument list, then exit.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_promote">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_promote">
<code class="option">
--promote
</code>
</a>
</p>
<a class="indexterm" name="idm46045096166192">
</a>
<a class="indexterm" name="idm46045096164704">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for promote">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--promote
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Promote pending files to active, then exit.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_remote-CA-host">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_remote-CA-host">
<code class="option">
--remote-CA-host
</code>
</a>
</p>
<a class="indexterm" name="idm46045096154992">
</a>
<a class="indexterm" name="idm46045096153504">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for remote-CA-host">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--remote-CA-host=hostname
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Specify the address or hostname of a remote CA host.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_remote-exec-path">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_remote-exec-path">
<code class="option">
--remote-exec-path
</code>
</a>
</p>
<a class="indexterm" name="idm46045096139200">
</a>
<a class="indexterm" name="idm46045096137712">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for remote-exec-path">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--remote-exec-path
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Path name
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Provide the full path to an executable on the remote CA host
specified with
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_remote-CA-host">
<code class="option">
--remote-CA-host
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_remote-openssl">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_remote-openssl">
<code class="option">
--remote-openssl
</code>
</a>
</p>
<a class="indexterm" name="idm46045096122400">
</a>
<a class="indexterm" name="idm46045096120912">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for remote-openssl">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--remote-openssl
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Use OpenSSL for signing of keys on the remote CA host
specified with
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_remote-CA-host">
<code class="option">
--remote-CA-host
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_replace-by">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_replace-by">
<code class="option">
--replace-by
</code>
</a>
</p>
<a class="indexterm" name="idm46045096110160">
</a>
<a class="indexterm" name="idm46045096108672">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for replace-by">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--replace-by=#
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Integer
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
-10
</code>
</td>
</tr>
<tr>
<th>
Minimum Value
</th>
<td>
<code class="literal">
-128
</code>
</td>
</tr>
<tr>
<th>
Maximum Value
</th>
<td>
<code class="literal">
127
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Suggest a certificate replacement date for periodic checks,
as a number of days after the CA expiration date. Use a
negative number to indicate days before expiration.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_rotate-CA">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_rotate-CA">
<code class="option">
--rotate-CA
</code>
</a>
</p>
<a class="indexterm" name="idm46045096089552">
</a>
<a class="indexterm" name="idm46045096088064">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for rotate-CA">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--rotate-CA
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Replace an older CA with a newer one. The new CA can be
created using OpenSSL, or you can allow
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html" title="25.5.28 ndb_sign_keys — Create, Sign, and Manage TLS Keys and Certificates for NDB Cluster">
<span class="command">
<strong>
ndb_sign_keys
</strong>
</span>
</a>
to create the new one, in
which case the new CA is created with an intermediate CA
certificate, signed by the old CA.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_schedule">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_schedule">
<code class="option">
--schedule
</code>
</a>
</p>
<a class="indexterm" name="idm46045096076816">
</a>
<a class="indexterm" name="idm46045096075328">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for schedule">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--schedule=list
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
String
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
120,10,130,10,150,0
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Assign a schedule of expiration dates to certificates. The
schedule is defined as a comma-delimited list of six
integers, in the format shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-simple"><div class="docs-select-all right" id="sa94776564"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-simple">api_valid<span class="token punctuation">,</span>api_extra<span class="token punctuation">,</span>dn_valid<span class="token punctuation">,</span>dn_extra<span class="token punctuation">,</span>mgm_valid<span class="token punctuation">,</span>mgm_extra</code></pre>
</div>
<p>
These values are defined as follows:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
<code class="literal">
api_valid
</code>
: A fixed number of days of
validity for client certificates.
</p>
<p>
<code class="literal">
api_extra
</code>
: A number of extra days for
client certificates.
</p>
<p>
<code class="literal">
dn_valid
</code>
: A fixed number of days of
validity for client certificates for data node
certificates.
</p>
<p>
<code class="literal">
dn_extra
</code>
: A number of extra days for
data node certificates.
</p>
<p>
<code class="literal">
mgm_valid
</code>
: A fixed number of days of
validity for management server certificates.
</p>
<p>
<code class="literal">
mgm_extra
</code>
: A number of extra days for
management server certificates.
</p>
</li>
</ul>
</div>
<p>
In other words, for each node type (API node, data node,
management node), certificates are created with a lifetime
equal to a whole fixed number of days, plus some random
amount of time less than or equal to the number of extra
days. The default schedule is shown here:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-simple"><div class="docs-select-all right" id="sa13892688"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-simple"><span class="token operator">--</span>schedule<span class="token operator">=</span>120<span class="token punctuation">,</span>10<span class="token punctuation">,</span>130<span class="token punctuation">,</span>10<span class="token punctuation">,</span>150<span class="token punctuation">,</span>0</code></pre>
</div>
<p>
Following the default schedule, client certificates begin
expiring on the 120
<sup>
th
</sup>
day, and
expire at random intervals over the next 10 days; data node
certificates expire at random times between the
130
<sup>
th
</sup>
and
140
<sup>
th
</sup>
days; and management node
certificates expire on the 150
<sup>
th
</sup>
day (with no random interval following).
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_sign">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_sign">
<code class="option">
--sign
</code>
</a>
</p>
<a class="indexterm" name="idm46045096047600">
</a>
<a class="indexterm" name="idm46045096046112">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for sign">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--sign
</code>
</td>
</tr>
<tr>
<th>
Disabled by
</th>
<td>
<code class="literal">
skip-sign
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Create signed certificates; enabled by default. Use
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_skip-sign">
<code class="option">
--skip-sign
</code>
</a>
to create
certificate signing requests instead.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_skip-sign">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_skip-sign">
<code class="option">
--skip-sign
</code>
</a>
</p>
<a class="indexterm" name="idm46045096032912">
</a>
<a class="indexterm" name="idm46045096031424">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for skip-sign">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--skip-sign
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Create certificate signing requests instead of signed
certificates.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_stdio">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_stdio">
<code class="option">
--stdio
</code>
</a>
</p>
<a class="indexterm" name="idm46045096021728">
</a>
<a class="indexterm" name="idm46045096020240">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for stdio">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--stdio
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Read certificate signing requests from
<code class="literal">
stdin
</code>
, and write X.509 to
<code class="literal">
stdout
</code>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_to-dir">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_to-dir">
<code class="option">
--to-dir
</code>
</a>
</p>
<a class="indexterm" name="idm46045096009200">
</a>
<a class="indexterm" name="idm46045096007712">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for to-dir">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--to-dir=dirname
</code>
</td>
</tr>
<tr>
<th>
Type
</th>
<td>
Directory name
</td>
</tr>
<tr>
<th>
Default Value
</th>
<td>
<code class="literal">
[none]
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Specify the output directory for created files. For private
key files, this can be overriden using
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_keys-to-dir">
<code class="option">
--keys-to-dir
</code>
</a>
.
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_usage">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_usage">
<code class="option">
--usage
</code>
</a>
</p>
<a class="indexterm" name="idm46045095992448">
</a>
<a class="indexterm" name="idm46045095990960">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for usage">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--usage
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Print help text, then exit (alias for
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_help">
<code class="option">
--help
</code>
</a>
).
</p>
</li>
<li class="listitem">
<p>
<a name="option_ndb_sign_keys_version">
</a>
<a class="link" href="mysql-cluster-programs-ndb-sign-keys.html#option_ndb_sign_keys_version">
<code class="option">
--version
</code>
</a>
</p>
<a class="indexterm" name="idm46045095980272">
</a>
<a class="indexterm" name="idm46045095978784">
</a>
<div class="informaltable">
<table frame="box" rules="all" summary="Properties for version">
<colgroup>
<col style="width: 30%"/>
<col style="width: 70%"/>
</colgroup>
<tbody>
<tr>
<th>
Command-Line Format
</th>
<td>
<code class="literal">
--version
</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
Print version information, then exit.
</p>
</li>
</ul>
</div>
</div>
<br/>
</div>
|
https://dev.mysql.com/doc/refman/8.4/en/locking-service.html | <div id="docs-body">
<div class="section">
<div class="titlepage">
<div>
<div>
<h4 class="title">
<a name="locking-service">
</a>
7.6.9.1 The Locking Service
</h4>
</div>
</div>
</div>
<a class="indexterm" name="idm46045254516576">
</a>
<a class="indexterm" name="idm46045254515088">
</a>
<p>
MySQL distributions provide a locking interface that is
accessible at two levels:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
At the SQL level, as a set of loadable functions that each
map onto calls to the service routines.
</p>
</li>
<li class="listitem">
<p>
As a C language interface, callable as a plugin service from
server plugins or loadable functions.
</p>
</li>
</ul>
</div>
<p>
For general information about plugin services, see
<a class="xref" href="plugin-services.html" title="7.6.9 MySQL Plugin Services">
Section 7.6.9, “MySQL Plugin Services”
</a>
. For general information about
loadable functions, see
<a class="ulink" href="/doc/extending-mysql/8.4/en/adding-loadable-function.html" target="_top">
Adding a Loadable Function
</a>
.
</p>
<p>
The locking interface has these characteristics:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
Locks have three attributes: Lock namespace, lock name, and
lock mode:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
<p>
Locks are identified by the combination of namespace and
lock name. The namespace enables different applications
to use the same lock names without colliding by creating
locks in separate namespaces. For example, if
applications A and B use namespaces of
<code class="literal">
ns1
</code>
and
<code class="literal">
ns2
</code>
,
respectively, each application can use lock names
<code class="literal">
lock1
</code>
and
<code class="literal">
lock2
</code>
without interfering with the other application.
</p>
</li>
<li class="listitem">
<p>
A lock mode is either read or write. Read locks are
shared: If a session has a read lock on a given lock
identifier, other sessions can acquire a read lock on
the same identifier. Write locks are exclusive: If a
session has a write lock on a given lock identifier,
other sessions cannot acquire a read or write lock on
the same identifier.
</p>
</li>
</ul>
</div>
</li>
<li class="listitem">
<p>
Namespace and lock names must be
non-
<code class="literal">
NULL
</code>
, nonempty, and have a maximum
length of 64 characters. A namespace or lock name specified
as
<code class="literal">
NULL
</code>
, the empty string, or a string
longer than 64 characters results in an
<a class="ulink" href="/doc/mysql-errors/8.4/en/server-error-reference.html#error_er_locking_service_wrong_name" target="_top">
<code class="literal">
ER_LOCKING_SERVICE_WRONG_NAME
</code>
</a>
error.
</p>
</li>
<li class="listitem">
<p>
The locking interface treats namespace and lock names as
binary strings, so comparisons are case-sensitive.
</p>
</li>
<li class="listitem">
<p>
The locking interface provides functions to acquire locks
and release locks. No special privilege is required to call
these functions. Privilege checking is the responsibility of
the calling application.
</p>
</li>
<li class="listitem">
<p>
Locks can be waited for if not immediately available. Lock
acquisition calls take an integer timeout value that
indicates how many seconds to wait to acquire locks before
giving up. If the timeout is reached without successful lock
acquisition, an
<a class="ulink" href="/doc/mysql-errors/8.4/en/server-error-reference.html#error_er_locking_service_timeout" target="_top">
<code class="literal">
ER_LOCKING_SERVICE_TIMEOUT
</code>
</a>
error occurs. If the timeout is 0, there is no waiting and
the call produces an error if locks cannot be acquired
immediately.
</p>
</li>
<li class="listitem">
<p>
The locking interface detects deadlock between
lock-acquisition calls in different sessions. In this case,
the locking service chooses a caller and terminates its
lock-acquisition request with an
<a class="ulink" href="/doc/mysql-errors/8.4/en/server-error-reference.html#error_er_locking_service_deadlock" target="_top">
<code class="literal">
ER_LOCKING_SERVICE_DEADLOCK
</code>
</a>
error. This error does not cause transactions to roll back.
To choose a session in case of deadlock, the locking service
prefers sessions that hold read locks over sessions that
hold write locks.
</p>
</li>
<li class="listitem">
<p>
A session can acquire multiple locks with a single
lock-acquisition call. For a given call, lock acquisition is
atomic: The call succeeds if all locks are acquired. If
acquisition of any lock fails, the call acquires no locks
and fails, typically with an
<a class="ulink" href="/doc/mysql-errors/8.4/en/server-error-reference.html#error_er_locking_service_timeout" target="_top">
<code class="literal">
ER_LOCKING_SERVICE_TIMEOUT
</code>
</a>
or
<a class="ulink" href="/doc/mysql-errors/8.4/en/server-error-reference.html#error_er_locking_service_deadlock" target="_top">
<code class="literal">
ER_LOCKING_SERVICE_DEADLOCK
</code>
</a>
error.
</p>
</li>
<li class="listitem">
<p>
A session can acquire multiple locks for the same lock
identifier (namespace and lock name combination). These lock
instances can be read locks, write locks, or a mix of both.
</p>
</li>
<li class="listitem">
<p>
Locks acquired within a session are released explicitly by
calling a release-locks function, or implicitly when the
session terminates (either normally or abnormally). Locks
are not released when transactions commit or roll back.
</p>
</li>
<li class="listitem">
<p>
Within a session, all locks for a given namespace when
released are released together.
</p>
</li>
</ul>
</div>
<p>
The interface provided by the locking service is distinct from
that provided by
<a class="link" href="locking-functions.html#function_get-lock">
<code class="literal">
GET_LOCK()
</code>
</a>
and
related SQL functions (see
<a class="xref" href="locking-functions.html" title="14.14 Locking Functions">
Section 14.14, “Locking Functions”
</a>
).
For example,
<a class="link" href="locking-functions.html#function_get-lock">
<code class="literal">
GET_LOCK()
</code>
</a>
does not
implement namespaces and provides only exclusive locks, not
distinct read and write locks.
</p>
<div class="section">
<div class="titlepage">
<div>
<div>
<h5 class="title">
<a name="locking-service-c-interface">
</a>
7.6.9.1.1 The Locking Service C Interface
</h5>
</div>
</div>
</div>
<p>
This section describes how to use the locking service C
language interface. To use the function interface instead, see
<a class="xref" href="locking-service.html#locking-service-interface" title="7.6.9.1.2 The Locking Service Function Interface">
Section 7.6.9.1.2, “The Locking Service Function Interface”
</a>
For general
characteristics of the locking service interface, see
<a class="xref" href="locking-service.html" title="7.6.9.1 The Locking Service">
Section 7.6.9.1, “The Locking Service”
</a>
. For general information
about plugin services, see
<a class="xref" href="plugin-services.html" title="7.6.9 MySQL Plugin Services">
Section 7.6.9, “MySQL Plugin Services”
</a>
.
</p>
<p>
Source files that use the locking service should include this
header file:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-c"><div class="docs-select-all right" id="sa83413049"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-c"><span class="token macro property">#<span class="token directive keyword">include</span> <span class="token string"><mysql/service_locking.h></span></span></code></pre>
</div>
<p>
To acquire one or more locks, call this function:
</p>
<a class="indexterm" name="idm46045254474112">
</a>
<a class="indexterm" name="idm46045254472592">
</a>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-c"><div class="docs-select-all right" id="sa39112813"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-c"><span class="token keyword">int</span> <span class="token function">mysql_acquire_locking_service_locks</span><span class="token punctuation">(</span>MYSQL_THD opaque_thd<span class="token punctuation">,</span>
<span class="token keyword">const</span> <span class="token keyword">char</span><span class="token operator">*</span> lock_namespace<span class="token punctuation">,</span>
<span class="token keyword">const</span> <span class="token keyword">char</span><span class="token operator">*</span><span class="token operator">*</span>lock_names<span class="token punctuation">,</span>
size_t lock_num<span class="token punctuation">,</span>
<span class="token keyword">enum</span> enum_locking_service_lock_type lock_type<span class="token punctuation">,</span>
<span class="token keyword">unsigned</span> <span class="token keyword">long</span> lock_timeout<span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
The arguments have these meanings:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
opaque_thd
</code>
: A thread handle. If
specified as
<code class="literal">
NULL
</code>
, the handle for the
current thread is used.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
lock_namespace
</code>
: A null-terminated
string that indicates the lock namespace.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
lock_names
</code>
: An array of null-terminated
strings that provides the names of the locks to acquire.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
lock_num
</code>
: The number of names in the
<code class="literal">
lock_names
</code>
array.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
lock_type
</code>
: The lock mode, either
<code class="literal">
LOCKING_SERVICE_READ
</code>
or
<code class="literal">
LOCKING_SERVICE_WRITE
</code>
to acquire read
locks or write locks, respectively.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
lock_timeout
</code>
: An integer number of
seconds to wait to acquire the locks before giving up.
</p>
</li>
</ul>
</div>
<p>
To release locks acquired for a given namespace, call this
function:
</p>
<a class="indexterm" name="idm46045254456160">
</a>
<a class="indexterm" name="idm46045254454640">
</a>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-c"><div class="docs-select-all right" id="sa49687193"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-c"><span class="token keyword">int</span> <span class="token function">mysql_release_locking_service_locks</span><span class="token punctuation">(</span>MYSQL_THD opaque_thd<span class="token punctuation">,</span>
<span class="token keyword">const</span> <span class="token keyword">char</span><span class="token operator">*</span> lock_namespace<span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
The arguments have these meanings:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<code class="literal">
opaque_thd
</code>
: A thread handle. If
specified as
<code class="literal">
NULL
</code>
, the handle for the
current thread is used.
</p>
</li>
<li class="listitem">
<p>
<code class="literal">
lock_namespace
</code>
: A null-terminated
string that indicates the lock namespace.
</p>
</li>
</ul>
</div>
<p>
Locks acquired or waited for by the locking service can be
monitored at the SQL level using the Performance Schema. For
details, see
<a class="xref" href="locking-service.html#locking-service-monitoring" title="Locking Service Monitoring">
Locking Service Monitoring
</a>
.
</p>
</div>
<div class="section">
<div class="titlepage">
<div>
<div>
<h5 class="title">
<a name="locking-service-interface">
</a>
7.6.9.1.2 The Locking Service Function Interface
</h5>
</div>
</div>
</div>
<p>
This section describes how to use the locking service
interface provided by its loadable functions. To use the C
language interface instead, see
<a class="xref" href="locking-service.html#locking-service-c-interface" title="7.6.9.1.1 The Locking Service C Interface">
Section 7.6.9.1.1, “The Locking Service C Interface”
</a>
For general
characteristics of the locking service interface, see
<a class="xref" href="locking-service.html" title="7.6.9.1 The Locking Service">
Section 7.6.9.1, “The Locking Service”
</a>
. For general information
about loadable functions, see
<a class="ulink" href="/doc/extending-mysql/8.4/en/adding-loadable-function.html" target="_top">
Adding a Loadable Function
</a>
.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a class="xref" href="locking-service.html#locking-service-function-installation" title="Installing or Uninstalling the Locking Service Function Interface">
Installing or Uninstalling the Locking Service Function Interface
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="locking-service.html#locking-service-function-usage" title="Using the Locking Service Function Interface">
Using the Locking Service Function Interface
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="locking-service.html#locking-service-monitoring" title="Locking Service Monitoring">
Locking Service Monitoring
</a>
</p>
</li>
<li class="listitem">
<p>
<a class="xref" href="locking-service.html#locking-service-function-reference" title="Locking Service Interface Function Reference">
Locking Service Interface Function Reference
</a>
</p>
</li>
</ul>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h6 class="title">
<a name="locking-service-function-installation">
</a>
Installing or Uninstalling the Locking Service Function Interface
</h6>
</div>
</div>
</div>
<a class="indexterm" name="idm46045254436272">
</a>
<a class="indexterm" name="idm46045254434784">
</a>
<p>
The locking service routines described in
<a class="xref" href="locking-service.html#locking-service-c-interface" title="7.6.9.1.1 The Locking Service C Interface">
Section 7.6.9.1.1, “The Locking Service C Interface”
</a>
need not be
installed because they are built into the server. The same
is not true of the loadable functions that map onto calls to
the service routines: The functions must be installed before
use. This section describes how to do that. For general
information about loadable function installation, see
<a class="xref" href="function-loading.html" title="7.7.1 Installing and Uninstalling Loadable Functions">
Section 7.7.1, “Installing and Uninstalling Loadable Functions”
</a>
.
</p>
<p>
The locking service functions are implemented in a plugin
library file located in the directory named by the
<a class="link" href="server-system-variables.html#sysvar_plugin_dir">
<code class="literal">
plugin_dir
</code>
</a>
system variable.
The file base name is
<code class="literal">
locking_service
</code>
.
The file name suffix differs per platform (for example,
<code class="filename">
.so
</code>
for Unix and Unix-like systems,
<code class="filename">
.dll
</code>
for Windows).
</p>
<p>
To install the locking service functions, use the
<a class="link" href="create-function.html" title="15.1.14 CREATE FUNCTION Statement">
<code class="literal">
CREATE FUNCTION
</code>
</a>
statement,
adjusting the
<code class="filename">
.so
</code>
suffix for your
platform as necessary:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa4666306"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">CREATE</span> <span class="token keyword">FUNCTION</span> service_get_read_locks <span class="token keyword">RETURNS</span> <span class="token datatype">INT</span>
<span class="token keyword">SONAME</span> <span class="token string">'locking_service.so'</span><span class="token punctuation">;</span>
<span class="token keyword">CREATE</span> <span class="token keyword">FUNCTION</span> service_get_write_locks <span class="token keyword">RETURNS</span> <span class="token datatype">INT</span>
<span class="token keyword">SONAME</span> <span class="token string">'locking_service.so'</span><span class="token punctuation">;</span>
<span class="token keyword">CREATE</span> <span class="token keyword">FUNCTION</span> service_release_locks <span class="token keyword">RETURNS</span> <span class="token datatype">INT</span>
<span class="token keyword">SONAME</span> <span class="token string">'locking_service.so'</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
If the functions are used on a replication source server,
install them on all replica servers as well to avoid
replication problems.
</p>
<p>
Once installed, the functions remain installed until
uninstalled. To remove them, use the
<a class="link" href="drop-function.html" title="15.1.26 DROP FUNCTION Statement">
<code class="literal">
DROP FUNCTION
</code>
</a>
statement:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa60427808"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">DROP</span> <span class="token keyword">FUNCTION</span> service_get_read_locks<span class="token punctuation">;</span>
<span class="token keyword">DROP</span> <span class="token keyword">FUNCTION</span> service_get_write_locks<span class="token punctuation">;</span>
<span class="token keyword">DROP</span> <span class="token keyword">FUNCTION</span> service_release_locks<span class="token punctuation">;</span></code></pre>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h6 class="title">
<a name="locking-service-function-usage">
</a>
Using the Locking Service Function Interface
</h6>
</div>
</div>
</div>
<p>
Before using the locking service functions, install them
according to the instructions provided at
<a class="xref" href="locking-service.html#locking-service-function-installation" title="Installing or Uninstalling the Locking Service Function Interface">
Installing or Uninstalling the Locking Service Function Interface
</a>
.
</p>
<p>
To acquire one or more read locks, call this function:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa56185116"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> service_get_read_locks<span class="token punctuation">(</span><span class="token string">'mynamespace'</span><span class="token punctuation">,</span> <span class="token string">'rlock1'</span><span class="token punctuation">,</span> <span class="token string">'rlock2'</span><span class="token punctuation">,</span> <span class="token number">10</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> service_get_read_locks('mynamespace', 'rlock1', 'rlock2', 10) <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
<p>
The first argument is the lock namespace. The final argument
is an integer timeout indicating how many seconds to wait to
acquire the locks before giving up. The arguments in between
are the lock names.
</p>
<p>
For the example just shown, the function acquires locks with
lock identifiers
<code class="literal">
(mynamespace, rlock1)
</code>
and
<code class="literal">
(mynamespace, rlock2)
</code>
.
</p>
<p>
To acquire write locks rather than read locks, call this
function:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa63793966"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> service_get_write_locks<span class="token punctuation">(</span><span class="token string">'mynamespace'</span><span class="token punctuation">,</span> <span class="token string">'wlock1'</span><span class="token punctuation">,</span> <span class="token string">'wlock2'</span><span class="token punctuation">,</span> <span class="token number">10</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> service_get_write_locks('mynamespace', 'wlock1', 'wlock2', 10) <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
<p>
In this case, the lock identifiers are
<code class="literal">
(mynamespace, wlock1)
</code>
and
<code class="literal">
(mynamespace, wlock2)
</code>
.
</p>
<p>
To release all locks for a namespace, use this function:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa30672818"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> service_release_locks<span class="token punctuation">(</span><span class="token string">'mynamespace'</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> service_release_locks('mynamespace') <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
</div>
<p>
Each locking function returns nonzero for success. If the
function fails, an error occurs. For example, the following
error occurs because lock names cannot be empty:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa36409363"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> service_get_read_locks<span class="token punctuation">(</span><span class="token string">'mynamespace'</span><span class="token punctuation">,</span> <span class="token string">''</span><span class="token punctuation">,</span> <span class="token number">10</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output">ERROR 3131 (42000)<span class="token punctuation">:</span> Incorrect locking service lock name ''.</span></code></pre>
</div>
<p>
A session can acquire multiple locks for the same lock
identifier. As long as a different session does not have a
write lock for an identifier, the session can acquire any
number of read or write locks. Each lock request for the
identifier acquires a new lock. The following statements
acquire three write locks with the same identifier, then
three read locks for the same identifier:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa30486410"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> service_get_write_locks<span class="token punctuation">(</span><span class="token string">'ns'</span><span class="token punctuation">,</span> <span class="token string">'lock1'</span><span class="token punctuation">,</span> <span class="token string">'lock1'</span><span class="token punctuation">,</span> <span class="token string">'lock1'</span><span class="token punctuation">,</span> <span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">SELECT</span> service_get_read_locks<span class="token punctuation">(</span><span class="token string">'ns'</span><span class="token punctuation">,</span> <span class="token string">'lock1'</span><span class="token punctuation">,</span> <span class="token string">'lock1'</span><span class="token punctuation">,</span> <span class="token string">'lock1'</span><span class="token punctuation">,</span> <span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
If you examine the Performance Schema
<code class="literal">
metadata_locks
</code>
table at this point, you
should find that the session holds six distinct locks with
the same
<code class="literal">
(ns, lock1)
</code>
identifier. (For
details, see
<a class="xref" href="locking-service.html#locking-service-monitoring" title="Locking Service Monitoring">
Locking Service Monitoring
</a>
.)
</p>
<p>
Because the session holds at least one write lock on
<code class="literal">
(ns, lock1)
</code>
, no other session can acquire
a lock for it, either read or write. If the session held
only read locks for the identifier, other sessions could
acquire read locks for it, but not write locks.
</p>
<p>
Locks for a single lock-acquisition call are acquired
atomically, but atomicity does not hold across calls. Thus,
for a statement such as the following, where
<a class="link" href="locking-service.html#function_service-get-write-locks">
<code class="literal">
service_get_write_locks()
</code>
</a>
is
called once per row of the result set, atomicity holds for
each individual call, but not for the statement as a whole:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa68678949"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SELECT</span> service_get_write_locks<span class="token punctuation">(</span><span class="token string">'ns'</span><span class="token punctuation">,</span> <span class="token string">'lock1'</span><span class="token punctuation">,</span> <span class="token string">'lock2'</span><span class="token punctuation">,</span> <span class="token number">0</span><span class="token punctuation">)</span> <span class="token keyword">FROM</span> t1 <span class="token keyword">WHERE</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token punctuation">;</span></code></pre>
</div>
<div class="caution" style="margin-left: 0.5in; margin-right: 0.5in;">
<div class="admon-title">
Caution
</div>
<p>
Because the locking service returns a separate lock for
each successful request for a given lock identifier, it is
possible for a single statement to acquire a large number
of locks. For example:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa90683664"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">INSERT</span> <span class="token keyword">INTO</span> <span class="token punctuation">.</span><span class="token punctuation">.</span><span class="token punctuation">.</span> <span class="token keyword">SELECT</span> service_get_write_locks<span class="token punctuation">(</span><span class="token string">'ns'</span><span class="token punctuation">,</span> t1<span class="token punctuation">.</span>col_name<span class="token punctuation">,</span> <span class="token number">0</span><span class="token punctuation">)</span> <span class="token keyword">FROM</span> t1<span class="token punctuation">;</span></code></pre>
</div>
<p>
These types of statements may have certain adverse
effects. For example, if the statement fails part way
through and rolls back, locks acquired up to the point of
failure still exist. If the intent is for there to be a
correspondence between rows inserted and locks acquired,
that intent is not satisfied. Also, if it is important
that locks are granted in a certain order, be aware that
result set order may differ depending on which execution
plan the optimizer chooses. For these reasons, it may be
best to limit applications to a single lock-acquisition
call per statement.
</p>
</div>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h6 class="title">
<a name="locking-service-monitoring">
</a>
Locking Service Monitoring
</h6>
</div>
</div>
</div>
<p>
The locking service is implemented using the MySQL Server
metadata locks framework, so you monitor locking service
locks acquired or waited for by examining the Performance
Schema
<code class="literal">
metadata_locks
</code>
table.
</p>
<p>
First, enable the metadata lock instrument:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa34829595"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">UPDATE</span> performance_schema<span class="token punctuation">.</span>setup_instruments <span class="token keyword">SET</span> ENABLED <span class="token operator">=</span> <span class="token string">'YES'</span>
<span class="token prompt"> -></span> <span class="token keyword">WHERE</span> <span class="token keyword">NAME</span> <span class="token operator">=</span> <span class="token string">'wait/lock/metadata/sql/mdl'</span><span class="token punctuation">;</span></code></pre>
</div>
<p>
Then acquire some locks and check the contents of the
<code class="literal">
metadata_locks
</code>
table:
</p>
<div class="copytoclipboard-wrapper">
<pre class="programlisting language-sql"><div class="docs-select-all right" id="sa6437262"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> service_get_write_locks<span class="token punctuation">(</span><span class="token string">'mynamespace'</span><span class="token punctuation">,</span> <span class="token string">'lock1'</span><span class="token punctuation">,</span> <span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> service_get_write_locks('mynamespace', 'lock1', 0) <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> service_get_read_locks<span class="token punctuation">(</span><span class="token string">'mynamespace'</span><span class="token punctuation">,</span> <span class="token string">'lock2'</span><span class="token punctuation">,</span> <span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> service_get_read_locks('mynamespace', 'lock2', 0) <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> 1 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token prompt">mysql></span> <span class="token keyword">SELECT</span> OBJECT_TYPE<span class="token punctuation">,</span> OBJECT_SCHEMA<span class="token punctuation">,</span> OBJECT_NAME<span class="token punctuation">,</span> LOCK_TYPE<span class="token punctuation">,</span> LOCK_STATUS
<span class="token prompt"> -></span> <span class="token keyword">FROM</span> performance_schema<span class="token punctuation">.</span>metadata_locks
<span class="token prompt"> -></span> <span class="token keyword">WHERE</span> OBJECT_TYPE <span class="token operator">=</span> <span class="token string">'LOCKING SERVICE'</span>\G
<span class="token output"><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span> 1. row <span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span>
OBJECT_TYPE<span class="token punctuation">:</span> LOCKING SERVICE
OBJECT_SCHEMA<span class="token punctuation">:</span> mynamespace
OBJECT_NAME<span class="token punctuation">:</span> lock1
LOCK_TYPE<span class="token punctuation">:</span> EXCLUSIVE
LOCK_STATUS<span class="token punctuation">:</span> GRANTED
<span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span> 2. row <span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span>
OBJECT_TYPE<span class="token punctuation">:</span> LOCKING SERVICE
OBJECT_SCHEMA<span class="token punctuation">:</span> mynamespace
OBJECT_NAME<span class="token punctuation">:</span> lock2
LOCK_TYPE<span class="token punctuation">:</span> SHARED
LOCK_STATUS<span class="token punctuation">:</span> GRANTED</span></code></pre>
</div>
<p>
Locking service locks have an
<code class="literal">
OBJECT_TYPE
</code>
value of
<code class="literal">
LOCKING SERVICE
</code>
. This is
distinct from, for example, locks acquired with the
<a class="link" href="locking-functions.html#function_get-lock">
<code class="literal">
GET_LOCK()
</code>
</a>
function, which
have an
<code class="literal">
OBJECT_TYPE
</code>
of
<code class="literal">
USER
LEVEL LOCK
</code>
.
</p>
<p>
The lock namespace, name, and mode appear in the
<code class="literal">
OBJECT_SCHEMA
</code>
,
<code class="literal">
OBJECT_NAME
</code>
, and
<code class="literal">
LOCK_TYPE
</code>
columns. Read and write locks
have
<code class="literal">
LOCK_TYPE
</code>
values of
<code class="literal">
SHARED
</code>
and
<code class="literal">
EXCLUSIVE
</code>
,
respectively.
</p>
<p>
The
<code class="literal">
LOCK_STATUS
</code>
value is
<code class="literal">
GRANTED
</code>
for an acquired lock,
<code class="literal">
PENDING
</code>
for a lock that is being waited
for. You can expect to see
<code class="literal">
PENDING
</code>
if one
session holds a write lock and another session is attempting
to acquire a lock having the same identifier.
</p>
</div>
<div class="simplesect">
<div class="titlepage">
<div>
<div class="simple">
<h6 class="title">
<a name="locking-service-function-reference">
</a>
Locking Service Interface Function Reference
</h6>
</div>
</div>
</div>
<p>
The SQL interface to the locking service implements the
loadable functions described in this section. For usage
examples, see
<a class="xref" href="locking-service.html#locking-service-function-usage" title="Using the Locking Service Function Interface">
Using the Locking Service Function Interface
</a>
.
</p>
<p>
The functions share these characteristics:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
The return value is nonzero for success. Otherwise, an
error occurs.
</p>
</li>
<li class="listitem">
<p>
Namespace and lock names must be
non-
<code class="literal">
NULL
</code>
, nonempty, and have a
maximum length of 64 characters.
</p>
</li>
<li class="listitem">
<p>
Timeout values must be integers indicating how many
seconds to wait to acquire locks before giving up with
an error. If the timeout is 0, there is no waiting and
the function produces an error if locks cannot be
acquired immediately.
</p>
</li>
</ul>
</div>
<p>
These locking service functions are available:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
<a name="function_service-get-read-locks">
</a>
<a class="link" href="locking-service.html#function_service-get-read-locks">
<code class="literal">
service_get_read_locks(
<em class="replaceable">
<code>
namespace
</code>
</em>
,
<em class="replaceable">
<code>
lock_name
</code>
</em>
[,
<em class="replaceable">
<code>
lock_name
</code>
</em>
] ...,
<em class="replaceable">
<code>
timeout
</code>
</em>
)
</code>
</a>
</p>
<a class="indexterm" name="idm46045254353456">
</a>
<a class="indexterm" name="idm46045254352000">
</a>
<p>
Acquires one or more read (shared) locks in the given
namespace using the given lock names, timing out with an
error if the locks are not acquired within the given
timeout value.
</p>
</li>
<li class="listitem">
<p>
<a name="function_service-get-write-locks">
</a>
<a class="link" href="locking-service.html#function_service-get-write-locks">
<code class="literal">
service_get_write_locks(
<em class="replaceable">
<code>
namespace
</code>
</em>
,
<em class="replaceable">
<code>
lock_name
</code>
</em>
[,
<em class="replaceable">
<code>
lock_name
</code>
</em>
] ...,
<em class="replaceable">
<code>
timeout
</code>
</em>
)
</code>
</a>
</p>
<a class="indexterm" name="idm46045254345600">
</a>
<a class="indexterm" name="idm46045254344096">
</a>
<p>
Acquires one or more write (exclusive) locks in the
given namespace using the given lock names, timing out
with an error if the locks are not acquired within the
given timeout value.
</p>
</li>
<li class="listitem">
<p>
<a name="function_service-release-locks">
</a>
<a class="link" href="locking-service.html#function_service-release-locks">
<code class="literal">
service_release_locks(
<em class="replaceable">
<code>
namespace
</code>
</em>
)
</code>
</a>
</p>
<a class="indexterm" name="idm46045254338896">
</a>
<a class="indexterm" name="idm46045254337440">
</a>
<p>
For the given namespace, releases all locks that were
acquired within the current session using
<a class="link" href="locking-service.html#function_service-get-read-locks">
<code class="literal">
service_get_read_locks()
</code>
</a>
and
<a class="link" href="locking-service.html#function_service-get-write-locks">
<code class="literal">
service_get_write_locks()
</code>
</a>
.
</p>
<p>
It is not an error for there to be no locks in the
namespace.
</p>
</li>
</ul>
</div>
</div>
</div>
</div>
<br/>
</div>
|