Received: from localhost (unknown [200.46.204.182]) by postgresql.org (Postfix) with ESMTP id 081D59F9C61 for ; Thu, 13 Sep 2007 13:19:50 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.182]) (amavisd-maia, port 10024) with ESMTP id 57975-05 for ; Thu, 13 Sep 2007 13:19:46 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from mail.libertyrms.com (vgateway.libertyrms.info [207.219.45.62]) by postgresql.org (Postfix) with ESMTP id 54F4F9F9A32 for ; Thu, 13 Sep 2007 13:19:47 -0300 (ADT) Received: from dba5.int.libertyrms.com ([10.1.3.44]) by mail.libertyrms.com with esmtp (Exim 4.22) id 1IVrPu-0001q9-7K; Thu, 13 Sep 2007 12:19:46 -0400 Subject: Re: Long Running Commits - Not Checkpoints From: Brad Nicholson To: Greg Smith Cc: pgsql-performance@postgresql.org In-Reply-To: References: <1189692915.8624.22.camel@bnicholson-desktop> Content-Type: text/plain Date: Thu, 13 Sep 2007 12:19:45 -0400 Message-Id: <1189700385.8624.32.camel@bnicholson-desktop> Mime-Version: 1.0 X-Mailer: Evolution 2.8.1 Content-Transfer-Encoding: 7bit X-SA-Exim-Mail-From: bnichols@ca.afilias.info X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.001 tagged_above=0 required=5 tests=AWL=-0.000, BAYES_50=0.001 X-Spam-Level: X-Archive-Number: 200709/252 X-Sequence-Number: 26797 On Thu, 2007-09-13 at 12:12 -0400, Greg Smith wrote: > On Thu, 13 Sep 2007, Brad Nicholson wrote: > I'd be curious to see how you've got your background writer configured to > see if it matches situations like this I've seen in the past. The > parameters controlling the all scan are the ones you'd might consider > turning down, definately the percentage and possibly the maxpages as well. bgwriter_delay = 50 # 10-10000 milliseconds between rounds bgwriter_lru_percent = 20.0 # 0-100% of LRU buffers scanned/round bgwriter_lru_maxpages = 300 # 0-1000 buffers max written/round bgwriter_all_percent = 20 # 0-100% of all buffers scanned/round bgwriter_all_maxpages = 600 # 0-1000 buffers max written/round -- Brad Nicholson 416-673-4106 Database Administrator, Afilias Canada Corp.