Received: from localhost (unknown [200.46.208.211]) by mail.postgresql.org (Postfix) with ESMTP id 273DD6326D0 for ; Thu, 7 Jan 2010 10:02:59 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.208.211]) (amavisd-maia, port 10024) with ESMTP id 50446-07 for ; Thu, 7 Jan 2010 14:02:40 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from moutng.kundenserver.de (moutng.kundenserver.de [212.227.17.8]) by mail.postgresql.org (Postfix) with ESMTP id 4BBFD6323EB for ; Thu, 7 Jan 2010 10:02:48 -0400 (AST) Received: from webserv.wug.de ([194.25.154.138]) by mrelayeu.kundenserver.de (node=mrbap1) with ESMTP (Nemesis) id 0MDF9A-1NhAAj03LQ-00HAkv; Thu, 07 Jan 2010 15:02:45 +0100 Received: from kretschmer by webserv.wug.de with local (Exim 3.36 #1) id 1NSswm-0003FI-00 for pgsql-performance@postgresql.org; Thu, 07 Jan 2010 15:02:44 +0100 Date: Thu, 7 Jan 2010 15:02:44 +0100 From: "A. Kretschmer" To: pgsql-performance@postgresql.org Subject: Re: Air-traffic benchmark Message-ID: <20100107140244.GD9884@a-kretschmer.de> References: <852badbc1001070438j36eb10d3qa22398ffcbef405f@mail.gmail.com> <4B45E36E.4040706@tweakers.net> <852badbc1001070547p48b47175vf87efc473e3bd41b@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <852badbc1001070547p48b47175vf87efc473e3bd41b@mail.gmail.com> X-OS: Debian/GNU Linux - weil ich es mir Wert bin! User-Agent: Mutt/1.5.9i X-Provags-ID: V01U2FsdGVkX189Gwf0IBorrQOh1eMITS078KyBz8L4fwQV8xC N+ozTz8mspU5Dngveh6xj2vuAUu/cgip13gqMv8IAKlpnUSL+i Ny0Xp03l4AiRa35q26rrw== X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.167 tagged_above=-10 required=5 tests=AWL=-0.427, BAYES_20=-0.74 X-Spam-Level: X-Archive-Number: 201001/89 X-Sequence-Number: 36969 In response to Lefteris : > Hi Arjen, > > so I understand from all of you that you don't consider the use of 25k > for sorting to be the cause of the slowdown? Probably I am missing > something on the specific sort algorithm used by PG. My RAM does fill > up, mainly by file buffers from linux, but postgres process remains to > 0.1% consumption of main memory. There is no way to force sort to use > say blocks of 128MB ? wouldn't that make a difference? The result-table fits in that piece of memory. You have only this little table: [ 5, 7509643 ] [ 1, 7478969 ] [ 4, 7453687 ] [ 3, 7412939 ] [ 2, 7370368 ] [ 7, 7095198 ] [ 6, 6425690 ] Andreas -- Andreas Kretschmer Kontakt: Heynitz: 035242/47150, D1: 0160/7141639 (mehr: -> Header) GnuPG: 0x31720C99, 1006 CCB4 A326 1D42 6431 2EB0 389D 1DC2 3172 0C99