Postgres support (transactions)

[nene]

• BEGIN
  • BEGIN [WORK | TRANSACTION]
  • START TRANSACTION
  • [transaction_mode [, ...]]:
    • ISOLATION LEVEL { SERIALIZABLE | REPEATABLE READ | READ COMMITTED | READ UNCOMMITTED }
    • READ WRITE | READ ONLY
    • [ NOT ] DEFERRABLE
• COMMIT
  • [ WORK | TRANSACTION ]
  • [ AND [ NO ] CHAIN ]
• END
  • [ WORK | TRANSACTION ]
  • [ AND [ NO ] CHAIN ]
• SAVEPOINT
  • SAVEPOINT savepoint_name
• ROLLBACK
  • [ WORK | TRANSACTION ]
  • [ AND [ NO ] CHAIN ]
• ABORT
  • [ WORK | TRANSACTION ]
  • [ AND [ NO ] CHAIN ]
• ROLLBACK TO SAVEPOINT
  • ROLLBACK TO name
  • [ WORK | TRANSACTION ]
  • [ SAVEPOINT ]
• RELEASE SAVEPOINT
  • RELEASE [ SAVEPOINT ] savepoint_name