Received: from makus.postgresql.org (makus.postgresql.org [98.129.198.125]) by mail.postgresql.org (Postfix) with ESMTP id 6F1D41F02EF3 for ; Thu, 26 Apr 2012 16:54:18 -0300 (ADT) Received: from 30.55.colo.spiretech.net ([69.168.55.30] helo=lists.commandprompt.com) by makus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1SNUlc-0002kS-Nm for pgsql-performance@postgresql.org; Thu, 26 Apr 2012 19:54:17 +0000 Received: from [192.168.1.5] (spinlock.commandprompt.com [69.168.55.30]) by lists.commandprompt.com (Postfix) with ESMTPA id B3721131; Thu, 26 Apr 2012 12:54:16 -0700 (PDT) Received: from [192.168.1.5] ([68.118.161.194] helo=[192.168.1.5]) by assp.commandprompt.com with ESMTPS(AES256-SHA) (2.1.1); 26 Apr 2012 12:54:16 -0700 Message-ID: <4F99A7BC.3030709@commandprompt.com> Date: Thu, 26 Apr 2012 12:53:32 -0700 From: "Joshua D. Drake" Organization: Command Prompt, Inc. User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120410 Thunderbird/11.0.1 MIME-Version: 1.0 To: Craig James CC: pgsql-performance@postgresql.org Subject: Re: auto-vacuum vs. full table update References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Assp-Version: 2.1.1(11364) on assp.commandprompt.com X-Assp-Client-SSL: yes X-Assp-ID: assp.commandprompt.com m1-70056-03298 X-Assp-Envelope-From: jd@commandprompt.com X-Assp-Intended-For: cjames@emolecules.com X-Assp-Original-Subject: Re: [PERFORM] auto-vacuum vs. full table update X-Pg-Spam-Score: -1.9 (-) X-Archive-Number: 201204/166 X-Sequence-Number: 46812 On 04/26/2012 12:49 PM, Craig James wrote: > > An update to our system means I'm going to be rewriting every row of > some large tables (20 million rows by 15 columns). In a situation > like this, can auto-vacuum take care of it, or should I plan on > vacuum-full/reindex to clean up? > If you rewrite the whole table, you will end up with a table twice the size, it will not be compacted but as the table grows, the old space will be reused. jD > This is 8.4.4. > > Thanks, > Craig > -- Command Prompt, Inc. - http://www.commandprompt.com/ PostgreSQL Support, Training, Professional Services and Development The PostgreSQL Conference - http://www.postgresqlconference.org/ @cmdpromptinc - @postgresconf - 509-416-6579