Received: from localhost (maia-3.hub.org [200.46.204.184]) by postgresql.org (Postfix) with ESMTP id 0A89E9FBB88 for ; Mon, 14 May 2007 10:52:42 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.184]) (amavisd-maia, port 10024) with ESMTP id 00786-03-3 for ; Mon, 14 May 2007 10:52:27 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id E41A19FBB94 for ; Mon, 14 May 2007 10:52:32 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.1/8.14.1) with ESMTP id l4EDqUMD009815; Mon, 14 May 2007 09:52:30 -0400 (EDT) To: Greg Smith cc: pgsql-patches@postgresql.org Subject: Re: Automatic adjustment of bgwriter_lru_maxpages In-reply-to: References: <461E108D.6080709@enterprisedb.com> <20070514174531.71E0.ITAGAKI.TAKAHIRO@oss.ntt.co.jp> Comments: In-reply-to Greg Smith message dated "Mon, 14 May 2007 09:34:21 -0400" Date: Mon, 14 May 2007 09:52:30 -0400 Message-ID: <9814.1179150750@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200705/185 X-Sequence-Number: 2285 Greg Smith writes: > Since the whole background writer setup is kind of complicated, the other > thing I was working on is writing a guide on how to use the new > pg_stat_bgwriter information to figure out if you need to increase > bgwriter_[all|lru]_pages (and the other parameters too). It makes it much > easier to write that if you can say "You can safely set > bgwriter_lru_maxpages high because it only writes what it needs to based > on your usage". If you can write something like that, why do we need the parameter at all? regards, tom lane