Re: Queries sometimes take 1000 times the normal time

From: "Anders K(dot) Pedersen" <akp(at)cohaesio(dot)com>
To: pgsql-performance(at)postgresql(dot)org
Subject: Re: Queries sometimes take 1000 times the normal time
Date: 2003-08-29 00:49:44
Message-ID: bim7v8$dbs$1@harrier.cohaesio.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

scott.marlowe wrote:
> Just to add to the clutch here, also check your bdflush settings (if
> you're on linux) or equivalent (if you're not.)
>
> Many times the swapping algo in linux can be quite bursty if you have it
> set to move too many pages at a time during cleanup / flush.

According to vmstat it doesn't swap near the spikes, so I don't think
this is the problem. I posted a vmstat sample in another reply, where
you can see an example of what happens.

Regards,
Anders K. Pedersen

In response to

Browse pgsql-performance by date

  From Date Subject
Next Message Bill Moran 2003-08-29 01:08:05 Taking another shot at the PostgreSQL/filesystem benchmarks
Previous Message Ken Geis 2003-08-29 00:10:31 bad estimates / non-scanning aggregates