Received: from localhost (unknown [200.46.204.184]) by developer.postgresql.org (Postfix) with ESMTP id B00BE2E00C5 for ; Mon, 7 Apr 2008 14:43:49 -0300 (ADT) Received: from developer.postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.184]) (amavisd-maia, port 10024) with ESMTP id 48738-01-4 for ; Mon, 7 Apr 2008 14:43:41 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from main2.mycybernet.net (main2.mycybernet.net [209.222.63.140]) by developer.postgresql.org (Postfix) with ESMTP id 070822E006B for ; Mon, 7 Apr 2008 14:39:54 -0300 (ADT) Received: from 227-54-222-209.mycybernet.net ([209.222.54.227] helo=crankycanuck.ca) by main2.mycybernet.net with esmtp (Exim 4.62) (envelope-from ) id 1JivJy-0003Rx-BF for pgsql-admin@postgresql.org; Mon, 07 Apr 2008 13:39:54 -0400 Received: by crankycanuck.ca (Postfix, from userid 1000) id 211A95014A; Mon, 7 Apr 2008 13:39:33 -0400 (EDT) Date: Mon, 7 Apr 2008 13:39:33 -0400 From: Andrew Sullivan To: pgsql-admin@postgresql.org Subject: Re: Tuning Message-ID: <20080407173933.GA7301@crankycanuck.ca> Mail-Followup-To: Andrew Sullivan , pgsql-admin@postgresql.org References: <6F737A76-FC25-4876-A6E0-163B87ECFAB0@indiana.edu> <60myo51uml.fsf@dba2.int.libertyrms.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <60myo51uml.fsf@dba2.int.libertyrms.com> User-Agent: Mutt/1.5.13 (2006-08-11) X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200804/56 X-Sequence-Number: 28820 On Mon, Apr 07, 2008 at 12:45:38PM -0400, Chris Browne wrote: > versions of PostgreSQL. e.g. - with v7.2, there were patterns of > updates that would leave portions of indexes not usable, but the issue > was rectified in ~7.4, and people have not been observing problems > relating to this former scenario. There remain use patterns that will leave the indexes in pretty bad shape. This is an inherent limiation with btrees, though -- if you just unbalanced the tree with a large number of deletes, there's nothing you can do except REINDEX. A