X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org
Received: from localhost (unknown [200.46.204.144])
	by svr1.postgresql.org (Postfix) with ESMTP id 783EF529BC;
	Fri, 22 Jul 2005 15:06:31 -0300 (ADT)
Received: from svr1.postgresql.org ([200.46.204.71])
	by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024)
	with ESMTP id 66823-02; Fri, 22 Jul 2005 18:06:21 +0000 (GMT)
Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130])
	by svr1.postgresql.org (Postfix) with ESMTP id 0670B52806;
	Fri, 22 Jul 2005 15:06:20 -0300 (ADT)
Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1])
	by sss.pgh.pa.us (8.13.1/8.13.1) with ESMTP id j6MI6HT8007215;
	Fri, 22 Jul 2005 14:06:17 -0400 (EDT)
To: Simon Riggs <simon@2ndquadrant.com>
Cc: Dawid Kuroczko <qnex42@gmail.com>,
	pgsql-performance@postgresql.org, pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] Planner doesn't look at LIMIT? 
In-reply-to: <1122053518.21502.180.camel@localhost.localdomain> 
References: <758d5e7f0507220210bfa4978@mail.gmail.com>
	<29473.1122043197@sss.pgh.pa.us> <6440.1122049220@sss.pgh.pa.us>
	<1122053518.21502.180.camel@localhost.localdomain>
Comments: In-reply-to Simon Riggs <simon@2ndquadrant.com>
	message dated "Fri, 22 Jul 2005 18:31:58 +0100"
Date: Fri, 22 Jul 2005 14:06:17 -0400
Message-ID: <7214.1122055577@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
X-Virus-Scanned: by amavisd-new at hub.org
X-Spam-Status: No, hits=0.006 tagged_above=0 required=5 tests=AWL
X-Spam-Level: 
X-Archive-Number: 200507/355
X-Sequence-Number: 13596

Simon Riggs <simon@2ndquadrant.com> writes:
> Looks good. I think it explains a few other wierd perf reports also.

Could be.  I went back to look at Sam Mason's report about three weeks
ago, and it definitely seems to explain his issue.  The "fuzzy cost
comparison" logic is new in 8.0 so it hasn't had all that much
testing...

			regards, tom lane