Received: from localhost (maia-2.hub.org [200.46.204.187]) by postgresql.org (Postfix) with ESMTP id AA9979FC161 for ; Thu, 29 Mar 2007 16:38:48 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.187]) (amavisd-maia, port 10024) with ESMTP id 78589-01-9 for ; Thu, 29 Mar 2007 16:38:37 -0300 (ADT) 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 699DC9FC15D for ; Thu, 29 Mar 2007 16:19:54 -0300 (ADT) 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 l2TJJnxU029111; Thu, 29 Mar 2007 15:19:49 -0400 (EDT) To: Erik Jones cc: PostgreSQL Performance Subject: Re: Shared buffers, db transactions commited, and write IO on Solaris In-reply-to: References: <9B7F4B34-7E96-4501-BCE0-D0BED739530A@myemma.com> <23286.1175184996@sss.pgh.pa.us> Comments: In-reply-to Erik Jones message dated "Thu, 29 Mar 2007 11:45:57 -0500" Date: Thu, 29 Mar 2007 15:19:49 -0400 Message-ID: <29109.1175195989@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200703/422 X-Sequence-Number: 23827 Erik Jones writes: > One very important thing to note here is that the number, or rather > rate, of disk writes has not changed. It's the volume of data in > those writes that has dropped, along with those transaction > mysterious counts. Hmm. I'm suddenly thinking about the stats collector: in existing 8.2.x releases it's got a bug that causes it to write the collected-stats file much too often. If you had done something that would shrink the size of the stats file, that might explain this observation. Do you have stats_reset_on_server_start turned on? The drop in reported transaction rate is still baffling though. Are you sure you're really doing the same amount of work? Can you estimate what you think the transaction rate *should* be from a what-are-your-clients- doing perspective? regards, tom lane