Received: from localhost (maia-1.hub.org [200.46.204.191]) by postgresql.org (Postfix) with ESMTP id C5ACB9FB33F for ; Fri, 18 May 2007 07:11:50 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.191]) (amavisd-maia, port 10024) with ESMTP id 20910-05 for ; Fri, 18 May 2007 07:11:46 -0300 (ADT) X-Greylist: delayed 00:22:12.176373 by SQLgrey-1.7.5 Received: from svr4.postgresql.org (svr4.postgresql.org [66.98.251.159]) by postgresql.org (Postfix) with ESMTP id AAFDE9FB34E for ; Fri, 18 May 2007 07:11:46 -0300 (ADT) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.3 Received: from cassarossa.samfundet.no (cassarossa.samfundet.no [129.241.93.19]) by svr4.postgresql.org (Postfix) with ESMTP id 718335AF038 for ; Fri, 18 May 2007 09:49:34 +0000 (GMT) Received: from trofast.sesse.net ([129.241.93.32]) by cassarossa.samfundet.no with esmtp (Exim 4.50) id 1Hoz5O-0007OU-4i; Fri, 18 May 2007 11:49:22 +0200 Received: from sesse by trofast.sesse.net with local (Exim 3.36 #1 (Debian)) id 1Hoz5N-0003Xy-00; Fri, 18 May 2007 11:49:21 +0200 Date: Fri, 18 May 2007 11:49:21 +0200 From: "Steinar H. Gunderson" To: Liviu Ionescu Cc: pgsql-performance@postgresql.org Subject: Re: performance drop on 8.2.4, reverting to 8.1.4 Message-ID: <20070518094921.GA13598@uio.no> Mail-Followup-To: Liviu Ionescu , pgsql-performance@postgresql.org References: <006501c7992b$4d29ffb0$653e10ac@ilgvaio> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <006501c7992b$4d29ffb0$653e10ac@ilgvaio> X-Operating-System: Linux 2.6.20.4 on a x86_64 X-Message-Flag: Outlook? --> http://www.mozilla.org/products/thunderbird/ User-Agent: Mutt/1.5.13 (2006-08-11) X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200705/313 X-Sequence-Number: 24703 On Fri, May 18, 2007 at 12:02:44PM +0300, Liviu Ionescu wrote: > the 8.2.4 plan with join_collapse_limit = 1 (with default it was worse, full of nested loops) It will probably be useful with EXPLAIN ANALYZE of your queries, not just the EXPLAIN. > "Nested Loop Left Join (cost=32.01..2012.31 rows=1 width=230)" It looks like the planner thinks this is going to be really cheap -- so it's misestimating something somewhere. Have you ANALYZEd recently? /* Steinar */ -- Homepage: http://www.sesse.net/