Received: from maia.hub.org (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id 44967632DF6 for ; Thu, 12 Nov 2009 10:50:03 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 71940-05 for ; Thu, 12 Nov 2009 14:49:55 +0000 (UTC) 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 487EF632557 for ; Thu, 12 Nov 2009 10:49:55 -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 nACEnr2P024026; Thu, 12 Nov 2009 09:49:53 -0500 (EST) To: Wayne Beaver cc: pgsql-performance@postgresql.org Subject: Re: Manual vacs 5x faster than autovacs? In-reply-to: <20091112093301.11953uc4r7pgqzy8@www.aceinnovative.com> References: <20091112093301.11953uc4r7pgqzy8@www.aceinnovative.com> Comments: In-reply-to Wayne Beaver message dated "Thu, 12 Nov 2009 09:33:01 -0500" Date: Thu, 12 Nov 2009 09:49:52 -0500 Message-ID: <24025.1258037392@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-2.599 tagged_above=-10 required=5 tests=BAYES_00=-2.599 X-Spam-Level: X-Archive-Number: 200911/124 X-Sequence-Number: 36292 Wayne Beaver writes: > Running Pg 8.3RC2, Linux server, w/8GB RAM, OpenSuSE 10.2 OS (yes, I > know that's old). I have seen *really* long-running autovacs eating up > system resources. While the below is not an example of *really* long, > it shows how I killed an autovac which had been running for more than > 10 minutes, then ran a VAC FULL ANALYZE on same exact table in about > ~2 min. Any wisdom here? Attributable to autovac_worker settings? autovacuum_vacuum_cost_delay. Is the slow autovac *really* eating a noticeable amount of system resources? I would think that a full speed manual vacuum would be a lot worse. regards, tom lane