Received: from maia.hub.org (maia-2.hub.org [200.46.204.251]) by mail.postgresql.org (Postfix) with ESMTP id 3244A133798F for ; Tue, 26 Oct 2010 08:59:12 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.251]) (amavisd-maia, port 10024) with ESMTP id 64272-06 for ; Tue, 26 Oct 2010 11:59:05 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from hermes.mejor.pl (hermes.mejor.pl [193.238.12.139]) by mail.postgresql.org (Postfix) with ESMTP id A70991336FA7 for ; Tue, 26 Oct 2010 08:59:04 -0300 (ADT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mejor.pl; s=cokolwiek; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:References:Subject:To:MIME-Version:From:Date:Message-ID; bh=VDZdZmXMJHTtrAoqBVhs28IbbyuKxh/KXgWGTykg1iU=; b=Q113IHzoOitpQY2desimHTmJPiGR7EgzwN1BhdvnUl2tJ/9Lp+zLcKrCKSXQlYD0RODkET1VfNL9fbaQG2TWcGV7BrffP9tWq5DLW1v/rLvBdZuPHrqSb/lOr5LfzIUW; Received: from 127-goc-33.acn.waw.pl ([94.75.108.127] helo=[192.168.138.87]) by hermes.mejor.pl with esmtpsa (TLSv1:DHE-RSA-CAMELLIA256-SHA:256) (Exim 4.72) (envelope-from ) id 1PAiBE-0005SX-4n for pgsql-performance@postgresql.org; Tue, 26 Oct 2010 13:59:04 +0200 Message-ID: <4CC6C287.8070803@mejor.pl> Date: Tue, 26 Oct 2010 13:59:03 +0200 From: =?UTF-8?B?TWFyY2luIE1pcm9zxYJhdw==?= User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.11) Gecko/20101020 Lightning/1.0b3pre Mnenhy/0.8.3 Thunderbird/3.1.5 MIME-Version: 1.0 To: pgsql-performance@postgresql.org Subject: Re: which one is faster References: In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-2.61 tagged_above=-10 required=5 tests=BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201010/421 X-Sequence-Number: 40839 W dniu 26.10.2010 12:59, Szymon Guz pisze: > both queries are the same. IMHO they aren't the same, but they returns the same value in this case. I mean count(field) doesn't count NULL values, count(*) does it. I'm writing this only for note:) Regards