Received: from localhost (unknown [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id AC3B3650221 for ; Sun, 24 Aug 2008 21:48:49 -0300 (ADT) Received: from postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 91674-03-2 for ; Sun, 24 Aug 2008 21:48:37 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from www.postnewspapers.com.au (www.postnewspapers.com.au [202.61.230.242]) by postgresql.org (Postfix) with ESMTP id 416B5650273 for ; Sun, 24 Aug 2008 21:30:21 -0300 (ADT) Received: from mail.postnewspapers.com.au (202-89-185-120.static.dsl.amnet.net.au [202.89.185.120]) by www.postnewspapers.com.au (Postfix) with ESMTP id D79EB5C0A1; Mon, 25 Aug 2008 08:30:18 +0800 (WST) Received: from [10.0.0.53] (wallace.localnet [10.0.0.53]) by mail.postnewspapers.com.au (Postfix) with ESMTP id BC21E1E0434; Mon, 25 Aug 2008 08:30:18 +0800 (WST) Message-ID: <48B1FD1A.7040807@postnewspapers.com.au> Date: Mon, 25 Aug 2008 08:30:18 +0800 From: Craig Ringer User-Agent: Icedove 1.5.0.14eol (X11/20080509) MIME-Version: 1.0 To: Peter Schuller Cc: pgsql-performance@postgresql.org Subject: Re: Identifying the nature of blocking I/O References: <20080822115243.GA10981@hyperion.scode.org> In-Reply-To: <20080822115243.GA10981@hyperion.scode.org> X-Enigmail-Version: 0.94.2.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0 tagged_above=0 required=5 tests=none X-Spam-Level: X-Archive-Number: 200808/313 X-Sequence-Number: 31194 Peter Schuller wrote: > But in general, it would be very interesting to see, at any given > moment, what PostgreSQL backends are actually blocking on from the > perspective of PostgreSQL. The recent work on DTrace support for PostgreSQL will probably give you the easiest path to useful results. You'll probably need an OpenSolaris or (I think) FreeBSD host, though, rather than a Linux host. -- Craig Ringer