Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1TdvmG-0008FM-Pk for pgsql-performance@arkaria.postgresql.org; Thu, 29 Nov 2012 04:31:08 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.72) (envelope-from ) id 1TdvmF-00078C-Qv for pgsql-performance@arkaria.postgresql.org; Thu, 29 Nov 2012 04:31:07 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1TdvmF-000787-1T for pgsql-performance@postgresql.org; Thu, 29 Nov 2012 04:31:07 +0000 Received: from [2404:130:0:10::40:2] (helo=mail.catalyst.net.nz) by magus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1Tdvm8-00059J-S6 for pgsql-performance@postgresql.org; Thu, 29 Nov 2012 04:31:05 +0000 Received: from localhost (localhost [127.0.0.1]) by mail.catalyst.net.nz (Postfix) with ESMTP id AC82567A38; Thu, 29 Nov 2012 17:30:53 +1300 (NZDT) X-Virus-Scanned: Debian amavisd-new at catalyst.net.nz Received: from mail.catalyst.net.nz ([127.0.0.1]) by localhost (bertrand.catalyst.net.nz [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id RbXthDObR9AN; Thu, 29 Nov 2012 17:30:53 +1300 (NZDT) Received: from [192.168.1.65] (122-60-64-230.jetstream.xtra.co.nz [122.60.64.230]) (Authenticated sender: mark.kirkwood) by mail.catalyst.net.nz (Postfix) with ESMTPSA id CB04E32CF6; Thu, 29 Nov 2012 17:30:52 +1300 (NZDT) Message-ID: <50B6E4FC.8040605@catalyst.net.nz> Date: Thu, 29 Nov 2012 17:30:52 +1300 From: Mark Kirkwood User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: =?ISO-8859-1?Q?Niels_Kristian_Schj=F8dt?= CC: sthomas@optionshouse.com, Willem Leenen , pgsql-performance@postgresql.org Subject: Re: Optimize update query References: <1C199C0D-13DF-47B3-944A-B0560C6D2E5A@autouncle.com> <50B61ABF.4070000@optionshouse.com>, <50B6223B.6000100@mejor.pl> <50B641AD.3020204@optionshouse.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable X-Host-Lookup-Failed: Reverse DNS lookup failed for 2404:130:0:10::40:2 (failed) X-Pg-Spam-Score: -1.1 (-) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-performance Precedence: bulk Sender: pgsql-performance-owner@postgresql.org In later kernels these have been renamed: Welcome to Ubuntu 12.04.1 LTS (GNU/Linux 3.2.0-32-generic x86_64) $ sysctl -a|grep dirty vm.dirty_background_ratio =3D 5 vm.dirty_background_bytes =3D 0 vm.dirty_ratio =3D 10 vm.dirty_bytes =3D 0 vm.dirty_writeback_centisecs =3D 500 vm.dirty_expire_centisecs =3D 3000 You the option of specifying either a ratio, or - more usefully for=20 machines with a lot of ram - bytes. Regards Mark P.s: People on this list usually prefer it if you *bottom* post (i.e=20 reply underneath the original). On 29/11/12 16:32, Niels Kristian Schj=F8dt wrote: > Hi, I have started to implement your suggestions . I have a small error s= o far though. The "vm.dirty_writeback_ratio =3D 1" command rerurns: > error: "vm.dirty_writeback_ratio" is an unknown key > I'm on ubuntu 12.04 > > --=20 Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance