On Jan 17, 2008 12:50 AM, Adrian Moisey <adrian@careerjunction.co.za> wrote:
> Hi
>
> >> Search this list for references to "checkpoints". If you run
> >> vmstat/iostat for a bit you should see bursts of disk activity at
> >> those times.
> >
> > The most straightforward way to prove or disprove that the slow queries
> > line up with checkpoints is to set to checkpoint_warning to a high value
> > (3600 should work), which should log every checkpoint, and then see if
> > they show up at the same time in the logs.
>
> You guys were spot on. During these pauses the IO goes up high.
You need to tune your background writer process. See this link:
http://www.westnet.com/~gsmith/content/postgresql/chkp-bgw-83.htm