X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [64.117.224.130]) by svr1.postgresql.org (Postfix) with ESMTP id 0C4FBD1B948 for ; Fri, 29 Aug 2003 08:17:57 +0000 (GMT) Received: from svr1.postgresql.org ([64.117.224.193]) by localhost (neptune.hub.org [64.117.224.130]) (amavisd-new, port 10024) with ESMTP id 00122-08 for ; Fri, 29 Aug 2003 05:17:27 -0300 (ADT) Received: from mail.speakeasy.net (mail11.speakeasy.net [216.254.0.211]) by svr1.postgresql.org (Postfix) with ESMTP id 84861D1B916 for ; Fri, 29 Aug 2003 05:17:24 -0300 (ADT) Received: (qmail 8190 invoked from network); 29 Aug 2003 08:17:25 -0000 Received: from unknown (HELO speakeasy.org) (kgeis@[66.93.130.165]) (envelope-sender ) by mail11.speakeasy.net (qmail-ldap-1.03) with AES256-SHA encrypted SMTP for ; 29 Aug 2003 08:17:25 -0000 Message-ID: <3F4F0C15.6040802@speakeasy.org> Date: Fri, 29 Aug 2003 01:17:25 -0700 From: Ken Geis User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4) Gecko/20030612 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Bruno Wolff III Cc: pgsql-performance@postgresql.org Subject: Re: bad estimates References: <3F4E99F7.7080604@speakeasy.org> <20030829025109.GD4373@wolff.to> <3F4EBF7E.8020602@speakeasy.org> <20030829030156.GF4373@wolff.to> <3F4EC1D0.5010503@speakeasy.org> <20030829033818.GA5577@wolff.to> <3F4ECC78.7090502@speakeasy.org> <20030829040519.GA5746@wolff.to> <3F4ED1DC.50808@speakeasy.org> <20030829042453.GA5931@wolff.to> <3F4EFA35.90401@speakeasy.org> In-Reply-To: <3F4EFA35.90401@speakeasy.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: by amavisd-new at postgresql.org X-Archive-Number: 200308/482 X-Sequence-Number: 3298 Ken Geis wrote: > When run on 7.3.3, forcing an index scan by setting > enable_seqscan=false, the query took 55 minutes to run. The index is > about 660M in size, and the table is 1G. As I mentioned before, with > table scans enabled, it bombs, running out of temporary space. Man, I should wait a while before I send mails, because I keep having more to say! Some good news here. Doing the same as above on 7.4beta2 took 29 minutes. Now, the 7.3.3 was on reiser and 7.4 on ext2, so take that as you will. 7.4's index selectivity estimate seems much better; 7.3.3's anticipated rows was ten times the actual; 7.4's is one half of the actual. Ken