One or more QUEL statements enclosed within a begin transaction-end transaction block constitutes a multi-query transaction (MQT). Any QUEL statement not within a begin transaction-end transaction block is a single-query transaction (SQT).

MQTs guarantee the atomic execution of a group of QUEL statements. Within MQTs you can declaring savepoints, which enable you to partially undo the effects of a transaction without aborting the transaction.

The following QUEL statements must not appear within an MQT: