Received: from localhost (unknown [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id 4F8672E02B8 for ; Wed, 12 Dec 2007 07:40:02 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 73238-04 for ; Wed, 12 Dec 2007 07:39:59 -0400 (AST) Received: from an-out-0708.google.com (an-out-0708.google.com [209.85.132.242]) by postgresql.org (Postfix) with ESMTP id 733182E02AE for ; Wed, 12 Dec 2007 07:39:59 -0400 (AST) Received: by an-out-0708.google.com with SMTP id c36so49647ana.33 for ; Wed, 12 Dec 2007 03:39:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; bh=NF3AuxiI/HyDWD5BmA53Eg3GJ30pXDElwQ1WgHBV9yw=; b=VholF1sBg8CO+o/WP6yhkKilH9sqVt0Hs3GjyEeg3IdPQ6bDZLSuYVyLzpHps9J79P+dTV+0EnkXj7aC1TYy9wu+5C+vdNSBUhe3H4PfWXj46HMc0ZSziSL4LR2vImJJJ5/KzrEaQHYRJkuINfZyWGEMM1tJlj11iv+l9YS/6pQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=jBMZkjyiTHQ9IJ+OLZVqgagX/+p5t+qWpxuHYbr3u1h0LXb/diAA98uku6S+No37TMB/kx+uE0NmIRLXsRhfeyrXmLxhjzVjzLX7UldOuRrnHnLLUUTe0RUrObpZz9/ZpV16zYe1E0NKVcpJogm82TfnMDXoOYCPTkcOIhbJ54s= Received: by 10.101.70.5 with SMTP id x5mr1284681ank.24.1197459598141; Wed, 12 Dec 2007 03:39:58 -0800 (PST) Received: by 10.100.242.10 with HTTP; Wed, 12 Dec 2007 03:39:58 -0800 (PST) Message-ID: Date: Wed, 12 Dec 2007 12:39:58 +0100 From: "Claus Guttesen" To: mlunnon@rwa-net.co.uk Subject: Re: Limited performance on multi core server Cc: pgsql-performance@postgresql.org In-Reply-To: <475FC22A.2070505@rwa-net.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <475FB50B.8060701@rwa-net.co.uk> <475FC22A.2070505@rwa-net.co.uk> X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200712/169 X-Sequence-Number: 27985 > Thanks for the information Claus, Why would reducing the effective cache > size help the processor usage? It seems that there is plenty of resources > on the box although I can see that 10MB of sort space could mount up if we > had 500 connections but at the moment we do not have anything like that > number. There is a discussion at http://archives.postgresql.org/pgsql-performance/2005-06/msg00477.php which can give a clearer picture. But in general rasing values can be counterproductive. If you know that you won't need more than 250 connections that would be a reasonable value. You may wan't to read http://www.varlena.com/GeneralBits/Tidbits/annotated_conf_e.html as well. This has some rules of thumb on the settings for 7.4.x. -- regards Claus When lenity and cruelty play for a kingdom, the gentlest gamester is the soonest winner. Shakespeare