Received: from maia.hub.org (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id 6DFE66330B5 for ; Mon, 9 Nov 2009 08:59:02 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 41686-02 for ; Mon, 9 Nov 2009 12:58:54 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from viefep20-int.chello.at (viefep20-int.chello.at [62.179.121.40]) by mail.postgresql.org (Postfix) with ESMTP id F4192632999 for ; Mon, 9 Nov 2009 08:58:53 -0400 (AST) Received: from edge02.upc.biz ([192.168.13.237]) by viefep20-int.chello.at (InterMail vM.7.09.01.00 201-2219-108-20080618) with ESMTP id <20091109125850.WKJK19022.viefep20-int.chello.at@edge02.upc.biz> for ; Mon, 9 Nov 2009 13:58:50 +0100 Received: from laci.sznet ([80.99.119.49]) by edge02.upc.biz with edge id 30yo1d04b1429wY020yply; Mon, 09 Nov 2009 13:58:50 +0100 X-SourceIP: 80.99.119.49 Message-ID: <4AF81207.4050008@shopzeus.com> Date: Mon, 09 Nov 2009 13:58:47 +0100 From: Laszlo Nagy User-Agent: Thunderbird 2.0.0.23 (X11/20090817) MIME-Version: 1.0 To: pgsql-performance Subject: random_page_cost for tablespace Content-Type: text/plain; charset=ISO-8859-2; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.001 tagged_above=-10 required=5 tests=BAYES_50=0.001 X-Spam-Level: X-Archive-Number: 200911/88 X-Sequence-Number: 36256 Hi All, We have a bigger table with some million rows. Number of index scans is high, number of seq reads is low. This table if often joined with others... so we want to buy a new SSD drive, create a tablespace on it and put this big table on it. Random read speed on SSD is identical to seq read. However, I need to tell the optimizer that random_page_cost is less for the new tablespace. Is there a way to do it? Thanks, Laszlo