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 D32A9D1B182 for ; Tue, 29 Jun 2004 11:57:52 -0300 (ADT) 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 11381-10 for ; Tue, 29 Jun 2004 14:57:51 +0000 (GMT) Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by svr1.postgresql.org (Postfix) with ESMTP id A5C35D1B188 for ; Tue, 29 Jun 2004 11:57:46 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.12.11/8.12.11) with ESMTP id i5TEvjpK029591; Tue, 29 Jun 2004 10:57:45 -0400 (EDT) To: Rich Hall Cc: pgsql-sql@postgresql.org Subject: Re: FW: "=" operator vs. "IS" In-reply-to: <40E17C81.3090308@micropat.com> References: <7A4ADADFC8AFF0478D47F63BEDD57CE33A320C@gpmail.gphq.genpathpharma.com> <40E17C81.3090308@micropat.com> Comments: In-reply-to Rich Hall message dated "Tue, 29 Jun 2004 10:28:17 -0400" Date: Tue, 29 Jun 2004 10:57:45 -0400 Message-ID: <29590.1088521065@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, hits=0.0 tagged_above=0.0 required=5.0 tests= X-Spam-Level: X-Archive-Number: 200406/288 X-Sequence-Number: 18233 Rich Hall writes: > My question is why is the form > "(anything) = NULL" > allowed? If you think it shouldn't be, you can turn on the transform_null_equals flag. However, past experience has shown that that breaks more things than it fixes. In any case, few people like to depend on such a thoroughly nonstandard behavior ... regards, tom lane