Received: from localhost (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id 02D2F63307C for ; Fri, 13 Feb 2009 22:02:57 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 48513-10 for ; Fri, 13 Feb 2009 22:02:54 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by mail.postgresql.org (Postfix) with ESMTP id 51482632E4B for ; Fri, 13 Feb 2009 22:02:54 -0400 (AST) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.2/8.14.2) with ESMTP id n1E22h6l023107; Fri, 13 Feb 2009 21:02:44 -0500 (EST) To: Scott Marlowe cc: Michael Monnerie , pgsql-admin@postgresql.org Subject: Re: Vacuum wait time problem In-reply-to: References: <4995ABC0.4090401@musicreports.com> <200902140102.09224@zmi.at> Comments: In-reply-to Scott Marlowe message dated "Fri, 13 Feb 2009 18:08:12 -0700" Date: Fri, 13 Feb 2009 21:02:43 -0500 Message-ID: <23106.1234576963@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0 tagged_above=0 required=5 tests=none X-Spam-Level: X-Archive-Number: 200902/97 X-Sequence-Number: 31318 Scott Marlowe writes: > On Fri, Feb 13, 2009 at 5:02 PM, Michael Monnerie > wrote: >> vacuum_cost_delay = 0 >> That was the trick for me. It was set to 250(ms), where it took 5 hours >> for a vacuum to run. Now it takes 5-15 minutes. > Wow!!! 250 ms is HUGE in the scheme of vacuum cost delay. even 10ms > is usually plenty to slow down vacuum enough to keep it out of your > way and double to quadruple your vacuum times. I wonder whether we ought to tighten the allowed range of vacuum_cost_delay. The upper limit is 1000ms at the moment; but that's clearly much higher than is useful, and it seems to encourage people to pick silly values ... regards, tom lane