Received: from localhost (unknown [200.46.204.184]) by postgresql.org (Postfix) with ESMTP id 28EA32E0066 for ; Tue, 19 Feb 2008 18:58:25 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.184]) (amavisd-maia, port 10024) with ESMTP id 70308-01-5 for ; Tue, 19 Feb 2008 18:58:12 -0400 (AST) Received: from westnet.com (westnet.com [216.187.52.2]) by postgresql.org (Postfix) with ESMTP id EE37E2E0098 for ; Tue, 19 Feb 2008 18:57:25 -0400 (AST) Received: from westnet.com (localhost [127.0.0.1]) by westnet.com (8.14.0/8.14.0) with ESMTP id m1JMvMst003164; Tue, 19 Feb 2008 17:57:22 -0500 (EST) Received: from localhost (gsmith@localhost) by westnet.com (8.14.0/8.13.2/Submit) with ESMTP id m1JMvLJb003161; Tue, 19 Feb 2008 17:57:21 -0500 (EST) X-Authentication-Warning: westnet.com: gsmith owned process doing -bs Date: Tue, 19 Feb 2008 17:57:21 -0500 (EST) From: Greg Smith X-X-Sender: gsmith@westnet.com To: JP Fletcher cc: pgsql-performance@postgresql.org Subject: Re: Fwd: wal_sync_methods for AIX In-Reply-To: <47BB3A3C.90407@ca.afilias.info> Message-ID: References: <20080215140453.4fafd9b1@commandprompt.com> <8B5845E3-6846-4335-888A-4EB94730C0B5@langille.org> <47BB3A3C.90407@ca.afilias.info> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200802/235 X-Sequence-Number: 28777 On Tue, 19 Feb 2008, JP Fletcher wrote: > Shared buffers are set to 50000, bgwriter settings are as follows: > > bgwriter_delay = 50 # 10-10000 milliseconds between > rounds > bgwriter_lru_percent = 20.0 # 0-100% of LRU buffers scanned/round > bgwriter_lru_maxpages = 300 # 0-1000 buffers max written/round > bgwriter_all_percent = 5 # 0-100% of all buffers scanned/round > bgwriter_all_maxpages = 600 # 0-1000 buffers max written/round Not that it impacts what you're asking about, but that's probably an excessive setting for bgwriter_lru_percent. With the reduced delay and scanning that much, you're burning a lot of CPU time doing that for little benefit. -- * Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD