Received: from maia.hub.org (maia-2.hub.org [200.46.204.251]) by mail.postgresql.org (Postfix) with ESMTP id B5F28B5DBD3 for ; Tue, 24 May 2011 06:12:37 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.251]) (amavisd-maia, port 10024) with ESMTP id 07882-05 for ; Tue, 24 May 2011 09:12:31 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail-bw0-f46.google.com (mail-bw0-f46.google.com [209.85.214.46]) by mail.postgresql.org (Postfix) with ESMTP id 9EB0CB5DBD9 for ; Tue, 24 May 2011 06:12:30 -0300 (ADT) Received: by bwz15 with SMTP id 15so5432906bwz.19 for ; Tue, 24 May 2011 02:12:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:message-id:date:from:user-agent:mime-version:to :cc:subject:references:in-reply-to:content-type :content-transfer-encoding; bh=VVhZu/cigeo9CNgIvLpzxLqJPoWTUoiO8Dr0sk4thr0=; b=iQEldMHPpxkYF0F0mED+rrzd94DYb5VyojQp7ba6tcDgJVgp7uoZjUzOX8tEn/NzJh WZWe5A1rqClcnkOl3lOkXaCBOeZ9mo5p/mHHfamLDD8J1Ur71C8a6TAMP1YIkbbVwmfK 23ETMQDu77uWyv3tDoZCCoNPP3EZaFjqNB1yQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=cuh9jje3YGxQQl/xLcWixeJFS2AXSF+LB9SozPiPZUjqRj6jrR0Tnxyo6iBErsX6y8 rvF+9CI0tfjqa5UzIh4Xpxyaewy4bZxVZPAhMf909lLmWMq8oSaiLDDE4ncfFU4lfaDO abERyH1Ek+uTEp9/PvOu8VWntC4aPMJLCYByw= Received: by 10.205.83.3 with SMTP id ae3mr3061798bkc.71.1306228350151; Tue, 24 May 2011 02:12:30 -0700 (PDT) Received: from [10.64.1.26] ([213.108.72.250]) by mx.google.com with ESMTPS id q25sm4415868bkk.10.2011.05.24.02.12.28 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 24 May 2011 02:12:28 -0700 (PDT) Message-ID: <4DDB7682.9040402@gmail.com> Date: Tue, 24 May 2011 12:12:34 +0300 From: Vitalii Tymchyshyn User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110424 Lightning/1.0b2 Thunderbird/3.1.10 MIME-Version: 1.0 To: Robert Haas CC: Josh Berkus , pgsql-performance@postgresql.org Subject: Re: reducing random_page_cost from 4 to 2 to force index scan References: <2823.1305314437@sss.pgh.pa.us> <4DCD90F5.2010501@agliodbs.com> <4DD0195A.9040305@agliodbs.com> <4DD07855.8080907@postnewspapers.com.au> <4DD07B4E.1020503@2ndquadrant.com> <4DD0AB16.5060808@krogh.cc> <4DD0ACD0.1090801@krogh.cc> <16676.1305560805@sss.pgh.pa.us> <4DD487CF.8010003@2ndquadrant.com> <091662B1-58B5-489D-8A92-0251A1E01E7C@nasby.net> <4DDAB097.9070505@agliodbs.com> 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-Spam-Status: No, hits=-0.345 tagged_above=-10 required=5 tests=BAYES_00=-1.9, FREEMAIL_ENVFROM_END_DIGIT=1.553, FREEMAIL_FROM=0.001, RFC_ABUSE_POST=0.001 X-Spam-Level: X-Archive-Number: 201105/322 X-Sequence-Number: 43831 Hello. As of me, all this "hot" thing really looks like uncertain and dynamic enough. Two things that I could directly use right now (and they are needed in pair) are: 1)Per-table/index/database bufferpools (split shared buffer into parts, allow to specify which index/table/database goes where) 2)Per-table/index cost settings If I had this, I could allocate specific bufferpools for tables/indexes that MUST be hot in memory and set low costs for this specific tables. P.S. Third thing, great to have to companion this two is "Load on startup" flag to automatically populate bufferpools with fast sequential read, but this can be easily emulated with a statement. Best regards, Vitalii Tymchyshyn