On Wed, Jan 28, 2009 at 12:19 AM, Abdul Rahman <abr_ora@xxxxxxxxx> wrote: > Dear All, > > PostgreSQL does not perform rollback action. Is it true? > no. postgresql executes all statements that are outside an explicit transaction in its own implicit one [1] executing commit at the end, if you cancelled the query the commit never executed and the records were never deleted... even more to the point, postgres never delete tuples on delete just mark them as invalid since transaction number X. at commit time the transaction is marked as correctly finished and all changes are WAL logged then suddenly changes take effect... rollback never mark the transaction as finished and doesn't save WAL records (that meaning that changes never spread to the datafiles) actually ROLLBACK is very cheap just don't save changes, COMMIT makes all the work... now, your post make me think that you think the ROLLBACK never executed based on... reponse time? very unscientific (there are plenty other reasons for that to happen) [1] http://www.postgresql.org/docs/8.3/static/tutorial-transactions.html -- Atentamente, Jaime Casanova Soporte y capacitación de PostgreSQL Asesoría y desarrollo de sistemas Guayaquil - Ecuador Cel. +59387171157 -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
