INSERT INTO tab1 VALUES ('val1', 'val2', 'val3'); COMMIT;
 Sync COMMITs
This is the default behavior.
COMMIT WRITE IMMEDIATE WAIT;
 Async COMMITs
COMMIT WRITE BATCH NOWAIT;
Async commits are normally a bad idea (transactions may be lost if the system crashes) and should only be allowed under very limited and controlled conditions.
When doing batch loads, you should rather do batch commits. This feature should only be used if batch commits cannot be done (which, in general should not be the case).
 COMMIT performance
To increase COMMIT performance, look at:
- don't COMMIT after each record, batch COMMITS together
- put your redo logs on faster disks
- ensure the DB doesn't switch too many logs (increase redo log size)
- use Async COMMITs