Received: from localhost (maia-3.hub.org [200.46.204.184]) by postgresql.org (Postfix) with ESMTP id 25DC59FB916 for ; Tue, 31 Jul 2007 18:32:05 -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 70718-07 for ; Tue, 31 Jul 2007 18:31:52 -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 F401B9FB8B0 for ; Tue, 31 Jul 2007 18:31:57 -0300 (ADT) X-EthosMedia-Virus-Scanned: no infections found Received: from [64.81.245.111] (account josh@agliodbs.com HELO [192.168.1.27]) by davinci.ethosmedia.com (CommuniGate Pro SMTP 4.1.8) with ESMTP-TLS id 12802146 for pgsql-performance@postgresql.org; Tue, 31 Jul 2007 14:36:07 -0700 From: Josh Berkus Reply-To: josh@agliodbs.com Organization: Aglio Database Solutions To: pgsql-performance@postgresql.org Subject: Re: User concurrency thresholding: where do I look? Date: Tue, 31 Jul 2007 14:33:20 -0700 User-Agent: KMail/1.8 References: <200707190828.59088.josh@agliodbs.com> <46A90F83.8050401@sun.com> <1185527727.4191.22.camel@ebony.site> In-Reply-To: <1185527727.4191.22.camel@ebony.site> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200707311433.20568.josh@agliodbs.com> X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200707/444 X-Sequence-Number: 26128 Simon, > Well thats pretty weird. That code path clearly only happens once per > transaction and ought to be fast. The other code paths that take > ProcArrayLock like TransactionIdIsInProgress() and GetSnapshotData() > ought to spend more time holding the lock. Presumably you are running > with a fair number of SERIALIZABLE transactions? Given that this is TPCC-analog, I'd assume that we are. Jignesh? -- --Josh Josh Berkus PostgreSQL @ Sun San Francisco