X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [64.117.224.130]) by svr1.postgresql.org (Postfix) with ESMTP id 9048ED1B8CD for ; Fri, 29 Aug 2003 17:04:03 +0000 (GMT) Received: from svr1.postgresql.org ([64.117.224.193]) by localhost (neptune.hub.org [64.117.224.130]) (amavisd-new, port 10024) with ESMTP id 40119-07 for ; Fri, 29 Aug 2003 14:03:33 -0300 (ADT) Received: from perrin.nxad.com (internal.nxad.com [69.1.70.251]) by svr1.postgresql.org (Postfix) with ESMTP id EFE08D1B8D8 for ; Fri, 29 Aug 2003 14:03:31 -0300 (ADT) Received: by perrin.nxad.com (Postfix, from userid 1001) id CAFD321058; Fri, 29 Aug 2003 10:03:31 -0700 (PDT) Date: Fri, 29 Aug 2003 10:03:31 -0700 From: Sean Chittenden To: Ken Geis Cc: Bruno Wolff III , pgsql-performance@postgresql.org Subject: Re: bad estimates Message-ID: <20030829170331.GA51353@perrin.nxad.com> References: <20030829025109.GD4373@wolff.to> <3F4EBF7E.8020602@speakeasy.org> <20030829030156.GF4373@wolff.to> <3F4EC1D0.5010503@speakeasy.org> <20030829033818.GA5577@wolff.to> <3F4ECC78.7090502@speakeasy.org> <20030829040519.GA5746@wolff.to> <3F4F7A07.30404@speakeasy.org> <20030829163613.GA51475@perrin.nxad.com> <3F4F85DB.2030402@speakeasy.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3F4F85DB.2030402@speakeasy.org> X-PGP-Key: finger seanc@FreeBSD.org X-PGP-Fingerprint: 3849 3760 1AFE 7B17 11A0 83A6 DD99 E31F BC84 B341 X-Web-Homepage: http://sean.chittenden.org/ User-Agent: Mutt/1.5.4i X-Virus-Scanned: by amavisd-new at postgresql.org X-Archive-Number: 200308/508 X-Sequence-Number: 3324 > >>I found I'm suffering from an effect detailed in a previous thread titled > >> > >> Does "correlation" mislead the optimizer on large tables? > > > > > >I don't know about large tables, but this is a big problem and > >something I'm going to spend some time validating later today. I > >think Manfred's patch is pretty good and certainly better than where > >we are but I haven't used it yet to see if it's the magic ticket for > >many of these index problems. > > I had to dig through a lot of archives to find this. Is this the patch, > from last October? > > http://members.aon.at/pivot/pg/16-correlation.diff > > If so, I'll try it out and report my results. Same guy, but that patch is pretty out of date and has been replaced by some newer work that's much better. From: Manfred Koizar Cc: pgsql-hackers@postgresql.org Subject: Re: [HACKERS] Correlation in cost_index() Date: Wed, 20 Aug 2003 19:57:12 +0200 Message-ID: and From: Manfred Koizar To: pgsql-hackers@postgresql.org Subject: [HACKERS] Again on index correlation Date: Wed, 20 Aug 2003 21:21:14 +0200 Message-ID: -sc -- Sean Chittenden