Message-ID: <547E1A3D.8040502@gmail.com>
Date: Tue, 02 Dec 2014 14:59:57 -0500
From: John Scalia <jayknowsunix@gmail.com>
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To: "pgsql-admin@postgresql.org" <pgsql-admin@postgresql.org>
Subject: 9.2 documentation/configuration question
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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


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