input: [Property name] DFT_ISOLATION [Return type] string [Description] 
output: The default transaction isolation level supported by the server: UR Uncommitted read: changes are immediately visible by all concurrent transactions. CS Cursor stability: a row read by one transaction can be altered and committed by a second concurrent transaction. RS Read stability: a transaction can add or remove rows matching a search condition or a pending transaction. RR Repeatable read: data affected by pending transaction is not available to other transactions. NC No commit: any changes are visible at the end of a successful operation. Explicit commits and rollbacks are not allowed.