-----Original Message----- From: pgsql-admin-owner@xxxxxxxxxxxxxx [mailto:pgsql-admin-owner@xxxxxxxxxxxxxx] On Behalf Of John Scalia Sent: Tuesday, December 02, 2014 3:00 PM To: pgsql-admin@xxxxxxxxxxxxxx Subject: 9.2 documentation/configuration question Hi All, I've been asked to assist another group in our company and their db configuration is a little confusing to me. The database is not replicated, but it is running WAL archiving. I've been looking at http://www.postgresql.org/docs/9.2/static/wal-configuration.html and my confusion regards the 4th paragraph: "The server's checkpointer process automatically performs a checkpoint every so often. A checkpoint is created every checkpoint_segments log segments, or every checkpoint_timeout seconds, whichever comes first. The default settings are 3 segments and 300 seconds (5 minutes), respectively. In cases where no WAL has been written since the previous checkpoint, new checkpoints will be skipped even if checkpoint_timeout has passed. If WAL archiving is being used and you want to put a lower limit on how often files are archived in order to bound potential data loss, you should adjust archive_timeout parameter rather than the checkpoint parameters..." So, are docs saying that checkpoint_timeout is ignored if you have a value for archive_timeout or is it still used? This server currently has: checkpoint_segments=32 checkpoint_timeout = 5min #default archive_timeout=3600 and I'm not sure these make sense together in light of this paragraph. -- Jay No, documentation says that even if WAL was not written, WAL archive will be created on archive_timeout, in your case at least once per hour. Regards, Igor Neyman -- Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
