Postgres Plus Advanced Server Oracle Compatibility Developer's Guide :
COMMIT -- commit the current transaction
COMMIT [ WORK ]
COMMIT commits the current transaction. All changes made by the transaction become visible to others and are guaranteed to be durable if a crash occurs.
Optional key word - has no effect.
Use ROLLBACK to abort a transaction. Issuing COMMIT when not inside a transaction does no harm.
To commit the current transaction and make all changes permanent: