Received: from magus.postgresql.org (magus.postgresql.org [87.238.57.229]) by mail.postgresql.org (Postfix) with ESMTP id 1C5DA19B3F2D for ; Mon, 28 Nov 2011 15:32:34 -0400 (AST) Received: from [2001:1528:137::f1] (helo=mail.gransy.com) by magus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1RV6wL-000148-II for pgsql-performance@postgresql.org; Mon, 28 Nov 2011 19:32:34 +0000 Received: from antispam.gransy.com (antispam.gransy.com [77.78.104.124]) by mail.gransy.com (Postfix) with ESMTP id D0EF94A21A7 for ; Mon, 28 Nov 2011 20:32:20 +0100 (CET) Received: from mail.gransy.com ([82.208.29.194]) by antispam.gransy.com (antispam.gransy.com [77.78.104.124]) (amavisd-new, port 10024) with ESMTP id YoHeKe9JjOA4 for ; Mon, 28 Nov 2011 20:32:20 +0100 (CET) Received: from [192.168.1.237] (ip-78-45-133-255.net.upcbroadband.cz [78.45.133.255]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.gransy.com (Postfix) with ESMTPSA id 95C824A21A4 for ; Mon, 28 Nov 2011 20:32:20 +0100 (CET) Message-ID: <4ED3E1C4.2050403@fuzzy.cz> Date: Mon, 28 Nov 2011 20:32:20 +0100 From: Tomas Vondra User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:8.0) Gecko/20111105 Thunderbird/8.0 MIME-Version: 1.0 To: pgsql-performance@postgresql.org Subject: Re: PostgreSQL 9.1 : why is this query slow? References: <1322498526.3343.22.camel@panoramix.Askesis.nl> In-Reply-To: <1322498526.3343.22.camel@panoramix.Askesis.nl> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Host-Lookup-Failed: Reverse DNS lookup failed for 2001:1528:137::f1 (failed) X-Pg-Spam-Score: 0.8 (/) X-Archive-Number: 201111/278 X-Sequence-Number: 45789 On 28.11.2011 17:42, Joost Kraaijeveld wrote: > - Why does explain say it takes "7876150720 rows"? Any idea where this number came from? No matter what I do, the nested loop row estimates are alway very close to the product of the two estimates (outer rows * inner rows). Tomas