ABORT [ WORK | TRANSACTION ]
The ABORT command rolls back the transaction currently in progress and discards any updates it may have made to the database. The command is used exactly the same as the SQL92 compliant command, ROLLBACK, and is included only for compatibility reasons. Remember to use the COMMIT to complete termination of a transaction.
The following example demonstrates the use of ABORT to undo an accidental delete.
booktown=# BEGIN WORK; BEGIN booktown=# DELETE FROM publishers WHERE id < 100; DELETE 6 booktown=# ABORT WORK; ROLLBACK