Received: from localhost (maia-1.hub.org [200.46.204.191]) by postgresql.org (Postfix) with ESMTP id 9B1BB9FB276; Thu, 11 Jan 2007 17:11:50 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.191]) (amavisd-new, port 10024) with ESMTP id 39320-06; Thu, 11 Jan 2007 17:11:43 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 X-Greylist: from auto-whitelisted by SQLgrey-1.7.4 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id 30D819FB273; Thu, 11 Jan 2007 17:11:44 -0400 (AST) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.6/8.13.6) with ESMTP id l0BLBe5b005415; Thu, 11 Jan 2007 16:11:40 -0500 (EST) To: "Simon Riggs" cc: "Kim" , pgsql-performance@postgresql.org, pgsql-hackers@postgresql.org Subject: Re: [HACKERS] unusual performance for vac following 8.2 upgrade In-reply-to: <1168548006.3951.564.camel@silverbirch.site> References: <45A671CD.1050706@myemma.com> <27939.1168539652@sss.pgh.pa.us> <45A68C74.4080405@myemma.com> <28949.1168544710@sss.pgh.pa.us> <1168548006.3951.564.camel@silverbirch.site> Comments: In-reply-to "Simon Riggs" message dated "Thu, 11 Jan 2007 20:40:06 +0000" Date: Thu, 11 Jan 2007 16:11:40 -0500 Message-ID: <5414.1168549900@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200701/186 X-Sequence-Number: 22787 "Simon Riggs" writes: > It's not clear to me how this fix will alter the INSERT issue Kim > mentions. I didn't say that it would; we have no information on the INSERT issue, so I'm just concentrating on the problem that he did provide info on. (BTW, I suppose the slow-\d issue is the regex planning problem we already knew about.) I'm frankly not real surprised that there are performance issues with such a huge pg_class; it's not a regime that anyone's spent any time optimizing. It is interesting that 8.2 seems to have regressed but I can think of several places that would've been bad before. One is that there are seqscans of pg_inherits ... regards, tom lane