Received: from localhost (maia-3.hub.org [200.46.204.184]) by postgresql.org (Postfix) with ESMTP id 2AAED9FB22E for ; Thu, 18 Jan 2007 18:11:42 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.184]) (amavisd-new, port 10024) with ESMTP id 23291-10 for ; Thu, 18 Jan 2007 18:11:35 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id 068F09FA2D3 for ; Thu, 18 Jan 2007 18:11:38 -0400 (AST) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.6/8.13.6) with ESMTP id l0IMBbri006827; Thu, 18 Jan 2007 17:11:37 -0500 (EST) To: Arjen van der Meijden cc: Jeremy Haile , Adam Rich , "'Bricklen Anderson'" , pgsql-performance@postgresql.org Subject: Re: Configuration Advice In-reply-to: <45AFE234.70301@tweakers.net> References: <090501c73a90$7f154330$6400a8c0@dualcore> <45AF4ACA.5060805@tweakers.net> <1169141307.10693.1169947257@webmail.messagingengine.com> <45AFE234.70301@tweakers.net> Comments: In-reply-to Arjen van der Meijden message dated "Thu, 18 Jan 2007 22:10:12 +0100" Date: Thu, 18 Jan 2007 17:11:37 -0500 Message-ID: <6826.1169158297@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200701/326 X-Sequence-Number: 22927 Arjen van der Meijden writes: > PS, In case any of the planner-hackers are reading, here are the plans > of the first two queries, just to see if something can be done to > decrease the differences between them. Increase work_mem? It's not taking the hash because it thinks it won't fit in memory ... There is a bug here, I'd say: the rowcount estimate ought to be the same either way. Dunno why it's not, but will look --- I see the same misbehavior with a toy table here. regards, tom lane