Received: from localhost (unknown [200.46.204.191]) by postgresql.org (Postfix) with ESMTP id 602902E3C70 for ; Wed, 16 Jan 2008 11:38:08 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.191]) (amavisd-maia, port 10024) with ESMTP id 19287-05-3 for ; Wed, 16 Jan 2008 11:38:03 -0400 (AST) Received: from westnet.com (westnet.com [216.187.52.2]) by postgresql.org (Postfix) with ESMTP id 8DC352E37E8 for ; Wed, 16 Jan 2008 11:38:03 -0400 (AST) Received: from westnet.com (localhost [127.0.0.1]) by westnet.com (8.14.0/8.14.0) with ESMTP id m0GFbxfe018965; Wed, 16 Jan 2008 10:37:59 -0500 (EST) Received: from localhost (gsmith@localhost) by westnet.com (8.14.0/8.13.2/Submit) with ESMTP id m0GFbxJ8018961; Wed, 16 Jan 2008 10:37:59 -0500 (EST) X-Authentication-Warning: westnet.com: gsmith owned process doing -bs Date: Wed, 16 Jan 2008 10:37:58 -0500 (EST) From: Greg Smith X-X-Sender: gsmith@westnet.com cc: Adrian Moisey , pgsql-performance@postgresql.org Subject: Re: strange pauses In-Reply-To: <478DE16F.50308@archonet.com> Message-ID: References: <478DDF83.8070106@careerjunction.co.za> <478DE16F.50308@archonet.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200801/135 X-Sequence-Number: 28374 On Wed, 16 Jan 2008, Richard Huxton wrote: > 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. -- * Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD