Received: from localhost (maia-5.hub.org [200.46.204.182]) by postgresql.org (Postfix) with ESMTP id 5E28C9F938C for ; Tue, 5 Dec 2006 15:56:04 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.182]) (amavisd-new, port 10024) with ESMTP id 99090-10 for ; Tue, 5 Dec 2006 15:55:50 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from cronos.madness.at (madness.at [217.196.146.217]) by postgresql.org (Postfix) with ESMTP id B163B9F9386 for ; Tue, 5 Dec 2006 15:55:57 -0400 (AST) Received: from mastermind.kaltenbrunner.cc ([83.215.233.60]) by cronos.madness.at with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.62 (FreeBSD)) (envelope-from ) id 1GrgOD-0004wJ-57; Tue, 05 Dec 2006 20:55:55 +0100 Message-ID: <4575CEBC.9030202@kaltenbrunner.cc> Date: Tue, 05 Dec 2006 20:55:40 +0100 From: Stefan Kaltenbrunner User-Agent: Thunderbird 1.5.0.7 (X11/20060927) MIME-Version: 1.0 To: sgunderson@bigfoot.com CC: pgsql-performance@postgresql.org Subject: Re: Performance of ORDER BY References: <4575A863.6040504@varianinc.com> <7090.1165341726@sss.pgh.pa.us> <20061205181733.GA10309@uio.no> In-Reply-To: <20061205181733.GA10309@uio.no> X-Enigmail-Version: 0.94.0.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200612/93 X-Sequence-Number: 22149 Steinar H. Gunderson wrote: > On Tue, Dec 05, 2006 at 01:02:06PM -0500, Tom Lane wrote: >> In 8.0 that might be counterproductively high --- we have seen cases >> where more sort_mem = slower with the older sorting code. I concur >> with Luke's advice that you should update to 8.2 (not 8.1) to get the >> improved sorting code. > > By the way, is the new sorting code any better for platforms that already > have a decent qsort() (like Linux)? yes - especially on-disk sorts will get some tremendous speedups in 8.2. Stefan