Received: from localhost (unknown [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id ED8BA6346BB for ; Mon, 30 Mar 2009 18:07:39 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 05094-01 for ; Mon, 30 Mar 2009 18:07:38 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from sprite.sidhe.org (75-54-192-43.uvs.wlfrct.sbcglobal.net [75.54.192.43]) by mail.postgresql.org (Postfix) with SMTP id 1F75463464B for ; Mon, 30 Mar 2009 18:07:37 -0300 (ADT) Received: (qmail 27406 invoked by uid 1021); 30 Mar 2009 21:07:36 -0000 Received: from localhost (HELO www.sidhe.org) (127.0.0.1) by sprite.sidhe.org (qpsmtpd/0.33-dev) with SMTP; Mon, 30 Mar 2009 17:07:36 -0400 Received: from 199.172.169.17 (SquirrelMail authenticated user dan) by localhost with HTTP; Mon, 30 Mar 2009 17:07:36 -0400 (EDT) Message-ID: <51413.199.172.169.17.1238447256.squirrel@localhost> In-Reply-To: <20090330210022.GG23023@alvh.no-ip.org> References: <603c8f070903301131p8086067ob552d09e8b21c82@mail.gmail.com> <56921.199.172.169.36.1238438533.squirrel@localhost> <57654.199.172.169.17.1238442145.squirrel@localhost> <56164.199.172.169.17.1238443348.squirrel@localhost> <603c8f070903301313u1a9606a3m27da187b5e376785@mail.gmail.com> <56504.199.172.169.35.1238445194.squirrel@localhost> <20090330203939.GF23023@alvh.no-ip.org> <61646.199.172.169.32.1238446195.squirrel@localhost> <20090330210022.GG23023@alvh.no-ip.org> Date: Mon, 30 Mar 2009 17:07:36 -0400 (EDT) Subject: Re: Trying to track down weird query stalls From: dan@sidhe.org To: "Alvaro Herrera" Cc: dan@sidhe.org,"Robert Haas" , "Scott Marlowe" , pgsql-performance@postgresql.org User-Agent: SquirrelMail/1.4.2 MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Priority: 3 Importance: Normal X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.1 tagged_above=0 required=5 tests=RDNS_DYNAMIC=0.1 X-Spam-Level: X-Archive-Number: 200903/431 X-Sequence-Number: 33353 > dan@sidhe.org escribió: >> > dan@sidhe.org escribió: >> > >> >> where libinstance.libdate <= 1238445044 >> >> and libinstance.enddate > 1238445044 >> >> and libinstance.libinstanceid = libobject.libinstanceid >> >> and libinstance.architecture = ? >> > >> > How are you generating the explain? My bet is that you're just >> > substituting a literal in the architecture condition, but if the >> driver >> > is smart then maybe it's preparating the query beforehand. You'll get >> a >> > different plan in that case. >> >> I don't think so. Perl's DBI is involved, but the statement's in a >> variable. > > So what's the "?" in the query you pasted earlier? The first ? (for architecture) is 1, the second ? (for branchid) is 0. They both should get passed to Postgres as $1 and $2, respectively, assuming DBD::Pg does its substitution right. (They're both supposed to go in as placeholders) -Dan