Received: from maia.hub.org (maia-5.hub.org [200.46.204.29]) by mail.postgresql.org (Postfix) with ESMTP id CF2001337B8A for ; Mon, 7 Feb 2011 19:56:14 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.29]) (amavisd-maia, port 10024) with ESMTP id 31664-04 for ; Mon, 7 Feb 2011 23:56:08 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from www.postnewspapers.com.au (www.postnewspapers.com.au [173.230.139.50]) by mail.postgresql.org (Postfix) with ESMTP id E37F91337B95 for ; Mon, 7 Feb 2011 19:56:06 -0400 (AST) Received: from localhost (localhost [127.0.0.1]) by www.postnewspapers.com.au (Postfix) with ESMTP id C97DE14A5; Mon, 7 Feb 2011 18:56:06 -0500 (EST) X-Virus-Scanned: amavisd-new at postnewspapers.com.au.com Received: from www.postnewspapers.com.au ([127.0.0.1]) by localhost (www.postnewspapers.com.au [127.0.0.1]) (amavisd-new, port 10024) with LMTP id YAP388fakwij; Mon, 7 Feb 2011 18:56:05 -0500 (EST) Received: from mail.postnewspapers.com.au (ppp171-128.static.internode.on.net [150.101.171.128]) by www.postnewspapers.com.au (Postfix) with ESMTP id 15CC519; Mon, 7 Feb 2011 18:56:05 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mail.postnewspapers.com.au (Postfix) with ESMTP id 1566DAE40F; Tue, 8 Feb 2011 07:56:04 +0800 (WST) X-Virus-Scanned: Debian amavisd-new at postnewspapers.com.au Received: from mail.postnewspapers.com.au ([127.0.0.1]) by localhost (mail.postnewspapers.com.au [127.0.0.1]) (amavisd-new, port 10024) with LMTP id f4swcQ40VEqt; Tue, 8 Feb 2011 07:55:58 +0800 (WST) Received: from [10.1.1.5] (124-168-239-98.dyn.iinet.net.au [124.168.239.98]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "Craig Ringer", Issuer "POST Certificate Authority" (verified OK)) by mail.postnewspapers.com.au (Postfix) with ESMTPSA id 6C47DAE46A; Tue, 8 Feb 2011 07:55:58 +0800 (WST) Message-ID: <4D50868C.1020209@postnewspapers.com.au> Date: Tue, 08 Feb 2011 07:55:56 +0800 From: Craig Ringer User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101209 Fedora/3.1.7-0.35.b3pre.fc14 Thunderbird/3.1.7 MIME-Version: 1.0 To: Greg Smith CC: felix , "pgsql-performance@postgresql.org" Subject: Re: Really really slow select count(*) References: <4D4C138C.7010304@2ndquadrant.com> <4D4C1555.40209@peak6.com> <4D4C2AC3.5020804@peak6.com> <4D4F6109.1090209@postnewspapers.com.au> <4D504275.5040103@2ndquadrant.com> In-Reply-To: <4D504275.5040103@2ndquadrant.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.91 tagged_above=-10 required=5 tests=BAYES_00=-1.9, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201102/293 X-Sequence-Number: 42431 On 02/08/2011 03:05 AM, Greg Smith wrote: > Accordingly I would expect any serious > attempt to add some auto-reduction behavior to be beset with argument, > and I'd never consider writing such a thing as a result. Too many > non-controversial things I could work on instead. Yep. I expressed my own doubts in the post I suggested that in. If Pg did auto-correct down, it'd be necessary to scream about it angrily and continuously, not just once during startup. Given that it's clear many people never even look at the logs ("what logs? where are they?") I think Pg would also have to send notices to the client. Problem is, many clients don't process notices/warnings, so particularly slack admins won't see that either. I'm not particularly excited about the idea. -- Craig Ringer