X-Original-To: pgsql-sql-postgresql.org@localhost.postgresql.org Received: from localhost (unknown [200.46.204.144]) by svr1.postgresql.org (Postfix) with ESMTP id 5CAEA3A561E for ; Thu, 2 Dec 2004 01:53:22 +0000 (GMT) Received: from svr1.postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 43061-04 for ; Thu, 2 Dec 2004 01:53:10 +0000 (GMT) Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by svr1.postgresql.org (Postfix) with ESMTP id EEDAE3A55B3 for ; Thu, 2 Dec 2004 01:53:11 +0000 (GMT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.1/8.13.1) with ESMTP id iB21rB6K028994; Wed, 1 Dec 2004 20:53:11 -0500 (EST) To: db@ke5in.com Cc: pgsql-sql@postgresql.org Subject: Re: find the "missing" rows In-reply-to: <33080.67.87.27.161.1101915810.squirrel@www.ke5in.com> References: <33080.67.87.27.161.1101915810.squirrel@www.ke5in.com> Comments: In-reply-to "Kevin B." message dated "Wed, 01 Dec 2004 10:43:30 -0500" Date: Wed, 01 Dec 2004 20:53:11 -0500 Message-ID: <28993.1101952391@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.001 tagged_above=0 required=5 tests=AWL X-Spam-Level: X-Archive-Number: 200412/15 X-Sequence-Number: 19635 "Kevin B." writes: > Select a.i, b.i > from t as a > left join t as b on a.i = b.i > where a.n = 'a' and b.n = 'b' and b.i is null This can't succeed since the b.n = 'b' condition is guaranteed to fail when b.* is nulled out ... regards, tom lane