Message-ID: <48E2A10C.9060602@pinpointresearch.com>
Date: Tue, 30 Sep 2008 14:58:36 -0700
From: Steve Crawford <scrawford@pinpointresearch.com>
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To: Carol Walter <walterc@indiana.edu>
CC: pgsql-admin@postgresql.org
Subject: Re: What process clears the logs?
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Carol Walter wrote:
> Ah-h-h, that's exactly my question.  What part of Postgres "takes care 
> of this itself."  I'm asking because I had 86 pg_clog files dated back 
> to mid-May.  I got the impression from something Tom said that backups 
> should prune this directory.  Perhaps my "impression" was wrong.  Most 
> databases I've used in the past have gotten rid of the transaction 
> logs, etc, when a backup is done. The restore process used that last 
> backup and then applied the transaction logs to it.  Once another 
> backup was completed the old transaction logs were no longer needed.  
> I'm trying to understand what happens "under the hood" so to speak.  
> What checkpoint_settings value are you referring to?
Sorry. I had a brain/fingers disconnect. I meant the 
"checkpoint_segments" setting. Anyway, answers to a number of your 
questions regarding write-ahead logging may be found here:
http://www.postgresql.org/docs/8.3/interactive/wal-configuration.html

Cheers,
Steve