Wow. That is a nice logging feature in 8.3!
Thanks,
Lance Campbell
Project Manager/Software Architect
Web Services at Public Affairs
University of Illinois
217.333.0382
http://webservices.uiuc.edu
-----Original Message-----
From: Bill Moran [mailto:wmoran@collaborativefusion.com]
Sent: Friday, November 09, 2007 2:08 PM
To: Campbell, Lance
Cc: pgsql-performance@postgresql.org
Subject: Re: [PERFORM] work_mem and shared_buffers
On Fri, 9 Nov 2007 12:08:57 -0600
"Campbell, Lance" <lance@uiuc.edu> wrote:
> How do you know when you should up the value of work_mem? Just play
> with the number. Is there a query I could do that would tell me if
> PostgreSql is performing SQL that could use more memory for sorting?
8.2 and older, it can be difficult to know, and I don't have a specific
recommendation.
8.3 includes a parameter to log the usage of temporary files by
Postgres.
When a sort can't fit in the available memory, it uses a temp file, thus
you could use this new feature to track when sorts don't fit in
work_mem.
--
Bill Moran
Potential Technologies
http://www.potentialtech.com
