Received: from localhost (maia-3.hub.org [200.46.204.184]) by postgresql.org (Postfix) with ESMTP id 4A6309FA28E for ; Mon, 1 Jan 2007 11:19:33 -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 22750-01 for ; Mon, 1 Jan 2007 11:19:01 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from web26309.mail.ukl.yahoo.com (web26309.mail.ukl.yahoo.com [217.146.176.20]) by postgresql.org (Postfix) with SMTP id D91C29F95E3 for ; Mon, 1 Jan 2007 11:19:06 -0400 (AST) Received: (qmail 55547 invoked by uid 60001); 1 Jan 2007 15:19:05 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.no; h=Message-ID:X-YMail-OSG:Received:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=2Dw3Ada7VwwEdW4+I+BGWdCXY8edQVwQ2GMhYwi8Gdz3lbnZnIJ2JhH/jq0fxKTz1rIkPI3z1TgcLhI3NwMKx5nJmWIHaz3whXO5BKqpVJxiGIOExYhcQPnFnXy9CL7fjJ5v5s7CF6wm8CGdkUKDN6i/nPL0WkocrswLR2ojMWs= ; Message-ID: <20070101151905.55545.qmail@web26309.mail.ukl.yahoo.com> X-YMail-OSG: 6_46.3oVM1krxW9ApHxUCot4l29TJrruh3Jq_Ph1GKmE1KO3SDJjNzpnksg5YPdJkkkA3QdaALI.kD.O9tWzwWP7F4qq1J6XnvUK3o9p1ekLTDrH2QUEmAEx_vUTaHHglvQSQ5wVNPnk Received: from [81.175.5.65] by web26309.mail.ukl.yahoo.com via HTTP; Mon, 01 Jan 2007 16:19:05 CET Date: Mon, 1 Jan 2007 16:19:05 +0100 (CET) From: =?iso-8859-1?q?Rolf=20=D8stvik?= Subject: Re: Worse perfomance on 8.2.0 than on 7.4.14 To: Tom Lane Cc: pgsql-performance@postgresql.org In-Reply-To: <4049.1167585088@sss.pgh.pa.us> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200701/3 X-Sequence-Number: 22604 --- Tom Lane skrev: > Rolf =?iso-8859-1?q?=D8stvik?= > writes: > > I have a simple query which uses 32ms on 7.4.14 > and 1015ms on 8.2.0. > > There's something awfully strange about that 8.2 > plan --- if it knew > that it'd have to scan all of uut_result_subset > (which it should have > known, if the stats were up-to-date), I can't really see the need for it to do an sequence scan, but that is me not knowing how things work. >why did it use > an indexscan > rather than a seqscan? Are you sure you haven't > tweaked any parameters > you didn't tell us about, such as setting > enable_seqscan = off? I haven't touched enable_seqscan. It could be that i have forgotton to tell you about a parameter i have tweaked, but i doubt it. Best regards Rolf Østvik __________________________________________________ Bruker du Yahoo!? Lei av spam? Yahoo! Mail har den beste spambeskyttelsen http://no.mail.yahoo.com