Received: from magus.postgresql.org (magus.postgresql.org [87.238.57.229]) by mail.postgresql.org (Postfix) with ESMTP id 4F751C24699 for ; Fri, 30 Dec 2011 13:40:41 -0400 (AST) Received: from sss.pgh.pa.us ([66.207.139.130]) by magus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1RggRW-000860-20 for pgsql-performance@postgresql.org; Fri, 30 Dec 2011 17:40:40 +0000 Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.2/8.14.2) with ESMTP id pBUHeJCq019328; Fri, 30 Dec 2011 12:40:19 -0500 (EST) To: miguel.silva@tactis.pt cc: pgsql-performance@postgresql.org Subject: Re: Query performance - normal on 9.0.4, slow from 9.0.5 onwards In-reply-to: <4EFDE928.50807@tactis.pt> References: <4EFDE928.50807@tactis.pt> Comments: In-reply-to Miguel Silva message dated "Fri, 30 Dec 2011 16:39:04 +0000" Date: Fri, 30 Dec 2011 12:40:19 -0500 Message-ID: <19327.1325266819@sss.pgh.pa.us> From: Tom Lane X-Pg-Spam-Score: -3.2 (---) X-Archive-Number: 201112/209 X-Sequence-Number: 46008 Miguel Silva writes: > But with postgresql version 9.0.5 (in version 9.0.4 all was fine), we > noticed the program was taking longer to start. In fact, in some clients > that had older hardware, it could take around 20 minutes when it usually > takes only a few seconds. To make a long story short, the problem was > traced and narrowed down to a single auto generated query. Here it is: > "SELECT [ snip ]" > ... Here are the explain analyzes. > enable_material ON: http://explain.depesz.com/s/wen > enable_material OFF: http://explain.depesz.com/s/Zaa It doesn't really accomplish anything to post anonymized explain output when you've already shown us the actual query, does it? Especially when said query involves only the system catalogs and by no stretch of the imagination could be thought to contain anything proprietary? regards, tom lane