X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 7A6E852C8E for ; Mon, 18 Jul 2005 10:23:17 -0300 (ADT) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 01371-04 for ; Mon, 18 Jul 2005 13:23:12 +0000 (GMT) Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by svr1.postgresql.org (Postfix) with ESMTP id 0950A52C7F for ; Mon, 18 Jul 2005 10:23:11 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.1/8.13.1) with ESMTP id j6IDNBGE002467; Mon, 18 Jul 2005 09:23:11 -0400 (EDT) To: Robert Creager Cc: PGPerformance , Andy Hewitt Subject: Re: Huge performance problem between 7.4.1 and 8.0.3 - CS In-reply-to: <20050717235630.26a7c979@thunder.logicalchaos.org> References: <20050717213416.59dcb52e@thunder.logicalchaos.org> <24520.1121659853@sss.pgh.pa.us> <20050717235630.26a7c979@thunder.logicalchaos.org> Comments: In-reply-to Robert Creager message dated "Sun, 17 Jul 2005 23:56:30 -0600" Date: Mon, 18 Jul 2005 09:23:11 -0400 Message-ID: <2466.1121692991@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.006 tagged_above=0 required=5 tests=AWL X-Spam-Level: X-Archive-Number: 200507/256 X-Sequence-Number: 13497 Robert Creager writes: > Tom Lane confessed: >> The context swap problem was no worse in 8.0 than in prior versions, >> so that hardly seems like a good explanation. Have you tried reverting >> to the cron-based vacuuming method you used in 7.4? > I've "vacuum_cost_delay = 10" in the conf file for 803. Hmm, did you read this thread? http://archives.postgresql.org/pgsql-performance/2005-07/msg00088.php It's still far from clear what's going on there, but it might be interesting to see if turning off the vacuum delay changes your results with 8.0. regards, tom lane