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 6949952875 for ; Sun, 12 Jun 2005 23:43:48 -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 68574-10 for ; Mon, 13 Jun 2005 02:43:43 +0000 (GMT) Received: from linda-4.paradise.net.nz (bm-4a.paradise.net.nz [202.0.58.23]) by svr1.postgresql.org (Postfix) with ESMTP id D6D3152864 for ; Sun, 12 Jun 2005 23:43:39 -0300 (ADT) Received: from smtp-1.paradise.net.nz (smtp-1a.paradise.net.nz [202.0.32.194]) by linda-4.paradise.net.nz (Paradise.net.nz) with ESMTP id <0II000LAJ4WVTT@linda-4.paradise.net.nz> for pgsql-performance@postgresql.org; Mon, 13 Jun 2005 14:43:43 +1200 (NZST) Received: from [192.168.1.11] (218-101-14-40.paradise.net.nz [218.101.14.40]) by smtp-1.paradise.net.nz (Postfix) with ESMTP id C30E582985; Mon, 13 Jun 2005 14:43:42 +1200 (NZST) Date: Mon, 13 Jun 2005 14:43:41 +1200 From: Mark Kirkwood Subject: Re: Updates on large tables are extremely slow In-reply-to: <579bc853ef3957c736c2773f13c444f7@implements.be> To: Yves Vindevogel Cc: pgsql-performance@postgresql.org Message-id: <42ACF2DD.8090409@paradise.net.nz> MIME-version: 1.0 Content-type: text/plain; format=flowed; charset=ISO-8859-1 Content-transfer-encoding: 7bit X-Accept-Language: en-us, en User-Agent: Mozilla Thunderbird 1.0.2 (X11/20050511) References: <579bc853ef3957c736c2773f13c444f7@implements.be> X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.151 tagged_above=0 required=5 tests=AWL X-Spam-Level: X-Archive-Number: 200506/267 X-Sequence-Number: 12904 Yves Vindevogel wrote: > > I'm trying to update a table that has about 600.000 records. > The update query is very simple : update mytable set pagesdesc = - pages ; > > The query takes about half an hour to an hour to execute. I have tried a > lot of things. > Half an hour seem a bit long - I would expect less than 5 minutes on reasonable hardware. You may have dead tuple bloat - can you post the output of 'ANALYZE VERBOSE mytable' ? Cheers Mark