Received: from localhost (maia-1.hub.org [200.46.204.191]) by postgresql.org (Postfix) with ESMTP id C8F089FC1BB for ; Thu, 21 Jun 2007 12:08:53 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.191]) (amavisd-maia, port 10024) with ESMTP id 06574-09 for ; Thu, 21 Jun 2007 12:08:50 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from developer.pgadmin.org (developer.pgadmin.org [63.246.23.140]) by postgresql.org (Postfix) with ESMTP id 6E95D9FC1AC for ; Thu, 21 Jun 2007 12:08:50 -0300 (ADT) Received: from [172.16.0.67] ([89.240.45.36]) (authenticated bits=0) by developer.pgadmin.org (8.13.8/8.13.8) with ESMTP id l5LF8hms025395 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 21 Jun 2007 15:08:45 GMT Message-ID: <467A9493.2090906@postgresql.org> Date: Thu, 21 Jun 2007 16:09:07 +0100 From: Dave Page User-Agent: Thunderbird 1.5.0.12 (Windows/20070509) MIME-Version: 1.0 To: Tom Lane CC: Greg Smith , pgsql-performance@postgresql.org Subject: Re: Volunteer to build a configuration tool References: <1182298719.4482.133.camel@ipso.snappymail.ca> <7621.1182318230@sss.pgh.pa.us> <9001.1182323187@sss.pgh.pa.us> <16078.1182436152@sss.pgh.pa.us> In-Reply-To: <16078.1182436152@sss.pgh.pa.us> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200706/466 X-Sequence-Number: 25499 Tom Lane wrote: > There's another reason for not setting shared_buffers huge, beyond the > good ones Greg listed: the kernel may or may not consider a large > shared-memory segment as potentially swappable. Another is that on Windows, shared memory access is more expensive and various people have noted that the smallest value for shared_buffers you can get away with can yield better performance as it leaves more free for the kernel to use, more efficiently. Regards, Dave.