Received: from localhost (unknown [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id AB906650E82 for ; Wed, 2 Jul 2008 13:35:44 -0300 (ADT) Received: from postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 66381-03 for ; Wed, 2 Jul 2008 13:35:37 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id EFF14650E8A for ; Wed, 2 Jul 2008 13:35:37 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.2/8.14.2) with ESMTP id m62GZVF2012785; Wed, 2 Jul 2008 12:35:31 -0400 (EDT) To: "Gauri Kanekar" cc: "Jonah H. Harris" , "=?ISO-8859-1?Q?Devrim_G=DCND=DCZ?=" , pgsql-performance@postgresql.org Subject: Re: Hot Issue In-reply-to: <7e4ba9550807020748r5b4749c2i6148d62573722368@mail.gmail.com> References: <7e4ba9550807020531w5480956fs2a1b5b630babda41@mail.gmail.com> <1215004084.2842.32.camel@laptop.gunduz.org> <7e4ba9550807020611x3dac7fffw8497d168c7a0e9d8@mail.gmail.com> <36e682920807020629h2b0432e9k39cc01f1693e6a40@mail.gmail.com> <7e4ba9550807020644j4f41530axd43317c7f180faed@mail.gmail.com> <36e682920807020721s3e537ef8k3189c8ce3b47e6c7@mail.gmail.com> <11126.1215009603@sss.pgh.pa.us> <7e4ba9550807020748r5b4749c2i6148d62573722368@mail.gmail.com> Comments: In-reply-to "Gauri Kanekar" message dated "Wed, 02 Jul 2008 20:18:11 +0530" Date: Wed, 02 Jul 2008 12:35:31 -0400 Message-ID: <12784.1215016531@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200807/30 X-Sequence-Number: 30630 "Gauri Kanekar" writes: > Better HOT performance means.... 1st stat showed most of the updated tuples > getting hot. > But the 2nd stat showed that most of the updated tuples are NOT getting hot. Well, as was noted upthread, you'd want to reduce the table fillfactor (not index fillfactor) below 100 to improve the odds of being able to do HOT updates. But I wonder whether your application behavior changed. Are you updating the rows in a way that'd make them wider? regards, tom lane