---------- Forwarded message ----------
From: Joseph S <jks@xxxxxxxxxxxxxxx>
To: Greg Smith <gsmith@xxxxxxxxxxxxx>, pgsql-performance@xxxxxxxxxxxxxx
Date: Fri, 28 Aug 2009 10:25:10 -0400
Subject: Re: What exactly is postgres doing during INSERT/UPDATE ?
Greg Smith wrote:
The main two things you can do to improve this on the database side:
-Increase checkpoint_segments, which reduces how often updated data has to be flushed to disk
It fsync is turned off, does this matter so much?
It still matters. The kernel is only willing to have so much dirty data sitting in the disk cache. Once it reaches that limit, user processes doing writes start blocking while the kernel flushes stuff on their behalf.
Jeff
