Received: from localhost (maia-5.hub.org [200.46.204.182]) by postgresql.org (Postfix) with ESMTP id B9C4A9FB3FC for ; Fri, 20 Jul 2007 01:37:50 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.182]) (amavisd-maia, port 10024) with ESMTP id 08927-06 for ; Fri, 20 Jul 2007 01:37:46 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from davinci.ethosmedia.com (server227.ethosmedia.com [209.128.84.227]) by postgresql.org (Postfix) with ESMTP id 3057F9FB3BC for ; Fri, 20 Jul 2007 01:37:47 -0300 (ADT) X-EthosMedia-Virus-Scanned: no infections found Received: from [63.195.55.98] (account josh@agliodbs.com HELO [192.168.2.3]) by davinci.ethosmedia.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 12701125; Thu, 19 Jul 2007 21:41:58 -0700 From: Josh Berkus Organization: PostgreSQL @ Sun To: Tom Lane Subject: Re: User concurrency thresholding: where do I look? Date: Thu, 19 Jul 2007 21:38:39 -0700 User-Agent: KMail/1.8.2 Cc: pgsql-performance@postgresql.org, Alvaro Herrera References: <200707190828.59088.josh@agliodbs.com> <200707191819.13899.josh@agliodbs.com> <15685.1184895926@sss.pgh.pa.us> In-Reply-To: <15685.1184895926@sss.pgh.pa.us> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200707192138.39679.josh@agliodbs.com> X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200707/256 X-Sequence-Number: 25940 Tom, > Well, if the load is a lot of short writing transactions then you'd > expect the throughput to depend on how fast stuff can be pushed down to > WAL. What have you got wal_buffers set to? Are you using a commit > delay? What's the I/O system anyway (any BB write cache on the WAL > disk?) and what wal sync method are you using? You know, I think Jignesh needs to me on this list so I can stop relaying questions on a workload I didn't design. Let me get him. -- Josh Berkus PostgreSQL @ Sun San Francisco