Re: Occasional Slow Commit - Mailing list pgsql-performance

From Andrew Sullivan
Subject Re: Occasional Slow Commit
Date
Msg-id 20081028124716.GE13363@crankycanuck.ca
Whole thread Raw
In response to Occasional Slow Commit  ("David Rees" <drees76@gmail.com>)
List pgsql-performance
On Mon, Oct 27, 2008 at 05:23:37PM -0700, David Rees wrote:

> However, occasionally, processing time will jump up significantly -
> the average processing time is around 20ms with the maximum processing
> time taking 2-4 seconds for a small percentage of transactions. Ouch!
>
> Turning on statement logging and analyzing the logs of the application
> itself shows that step #4 is the culprit of the vast majority of the
> slow transactions.

My bet is that you're waiting on checkpoints.  Given that you're on
8.3, start fiddling with the checkpoint_completion_target parameter.
0.7 might help.

A

--
Andrew Sullivan
ajs@commandprompt.com
+1 503 667 4564 x104
http://www.commandprompt.com/

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