Received: from localhost (maia-2.hub.org [200.46.204.187]) by postgresql.org (Postfix) with ESMTP id 8DE6E9FB72B for ; Thu, 7 Jun 2007 20:05:19 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.187]) (amavisd-maia, port 10024) with ESMTP id 01237-07 for ; Thu, 7 Jun 2007 20:05:02 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from smtp3.clear.net.nz (smtp3.clear.net.nz [203.97.33.64]) by postgresql.org (Postfix) with ESMTP id 885D49FB902 for ; Thu, 7 Jun 2007 20:05:13 -0300 (ADT) Received: from [192.168.1.11] (121-72-72-14.dsl.telstraclear.net [121.72.72.14]) by smtp3.clear.net.nz (CLEAR Net Mail) with ESMTP id <0JJA008YRG4MYX30@smtp3.clear.net.nz> for pgsql-performance@postgresql.org; Fri, 08 Jun 2007 11:05:11 +1200 (NZST) Date: Fri, 08 Jun 2007 11:04:54 +1200 From: Mark Kirkwood Subject: Re: Weird 8.2.4 performance In-reply-to: To: Kurt Overberg Cc: pgsql-performance@postgresql.org Message-id: <46688F16.90207@paradise.net.nz> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7bit References: <371D1936-E96B-4865-AEEF-C82AC41C2982@hotdogrecords.com> <46674AEF.6040803@paradise.net.nz> <4667CE87.30101@archonet.com> User-Agent: Thunderbird 1.5.0.10 (X11/20070313) X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200706/144 X-Sequence-Number: 25177 Kurt Overberg wrote: > work_mem = 100MB # when I ran the original query, > this was set to 1MB, increased on Mark Kirkwood's advice, seemed to help > a bit but not really > For future reference, be careful with this parameter, as *every* connection will use this much memory for each sort or hash (i.e it's not shared and can be allocated several times by each connection!)...yeah, I know I suggested increasing it to see what effect it would have :-). And I'd agree with Steiner and others, looks like caching effects are the cause of the timing difference between production and the mac! Cheers Mark