Received: from localhost (unknown [200.46.204.183]) by postgresql.org (Postfix) with ESMTP id 04C9D9F9B60 for ; Tue, 4 Sep 2007 01:56:54 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 10994-03 for ; Tue, 4 Sep 2007 01:56:51 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id 4D22B9F994D for ; Tue, 4 Sep 2007 01:56:51 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.1/8.14.1) with ESMTP id l844ukvC014041; Tue, 4 Sep 2007 00:56:46 -0400 (EDT) To: Bryce Nesbitt cc: pgsql-sql@postgresql.org Subject: Re: Difference between "foo is false" and "foo=false"? Partial index on boolean. In-reply-to: <46DCE263.6040207@obviously.com> References: <46DCE263.6040207@obviously.com> Comments: In-reply-to Bryce Nesbitt message dated "Mon, 03 Sep 2007 21:43:15 -0700" Date: Tue, 04 Sep 2007 00:56:46 -0400 Message-ID: <14040.1188881806@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200709/20 X-Sequence-Number: 29233 Bryce Nesbitt writes: > Could someone explain > the difference between "foo=false" and "foo is false", for a boolean > type column? They give different results for NULL --- specifically, NULL for the former and FALSE for the latter. Don't blame me, it's in the spec... regards, tom lane