Received: from localhost (unknown [200.46.204.184]) by postgresql.org (Postfix) with ESMTP id 8A68B9F9980 for ; Mon, 10 Sep 2007 17:53:01 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.184]) (amavisd-maia, port 10024) with ESMTP id 08592-09 for ; Mon, 10 Sep 2007 17:52:54 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from ironport2-out.pppoe.ca (ironport2-out.pppoe.ca [206.248.154.182]) by postgresql.org (Postfix) with ESMTP id 74CA19F9839 for ; Mon, 10 Sep 2007 17:52:58 -0300 (ADT) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ao8CAMdJ5UbO+Igp/2dsb2JhbAA X-IronPort-AV: E=Sophos;i="4.20,233,1186372800"; d="scan'208";a="6202327" Received: from smtp.pppoe.ca ([65.39.196.238]) by ironport2-out.pppoe.ca with ESMTP; 10 Sep 2007 16:52:56 -0400 Received: from [206.248.136.41] ([206.248.136.41]) by smtp.pppoe.ca (Internet Mail Server v1.0) with ESMTP id PDK64456; Mon, 10 Sep 2007 16:52:56 -0400 Message-ID: <46E5AEA8.4010809@mark.mielke.cc> Date: Mon, 10 Sep 2007 16:52:56 -0400 From: Mark Mielke User-Agent: Thunderbird 2.0.0.5 (X11/20070719) MIME-Version: 1.0 To: Luke Lonergan CC: Carlo Stonebanks , pgsql-performance@postgresql.org Subject: Re: random_page_costs - are defaults of 4.0 realistic for SCSI RAID 1 References: In-Reply-To: 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: 200709/160 X-Sequence-Number: 26705 Luke Lonergan wrote: > Should be a lot higher, something like 10-15 is approximating accurate. > In my own case, I have a much smaller database that I normally work with, where everything should fit in memory (100 Mbytes?), and reducing it to 3.0 has resulted in consistently better timings for me. I think this means that the planner doesn't understand my database size : effective memory size ratio. :-) Anyways - my point is that if you change the default to 10 you may hurt people like me. Cheers, mark -- Mark Mielke