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 3985B5E46C1 for ; Wed, 18 Aug 2004 10:57:01 -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 81678-01 for ; Wed, 18 Aug 2004 13:57:01 +0000 (GMT) Received: from web11.manitu.net (web11.manitu.net [217.11.48.111]) by svr1.postgresql.org (Postfix) with ESMTP id 338665E46EA for ; Wed, 18 Aug 2004 10:56:58 -0300 (ADT) Received: from [62.165.4.166] (dicaprio.akademie1.de [62.165.4.166]) (authenticated) by web11.manitu.net (8.10.2-SOL3/8.10.2) with ESMTP id i7IDnQg07367; Wed, 18 Aug 2004 15:49:26 +0200 Subject: Re: multi column foreign key for implicitly unique columns From: Markus Bertheau To: Jan Wieck Cc: Josh Berkus , olly@lfix.co.uk, pgsql-sql@postgresql.org In-Reply-To: <41235A90.1080300@Yahoo.com> References: <1092734724.2627.4.camel@dicaprio.akademie1.de> <1092735576.28365.48.camel@linda> <1092736197.2627.12.camel@dicaprio.akademie1.de> <200408171945.15663.josh@agliodbs.com> <41235A90.1080300@Yahoo.com> Content-Type: text/plain; charset=UTF-8 Message-Id: <1092836961.2630.3.camel@dicaprio.akademie1.de> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Wed, 18 Aug 2004 15:49:21 +0200 Content-Transfer-Encoding: quoted-printable 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: 200408/190 X-Sequence-Number: 18687 =D0=92 =D0=A1=D1=80=D0=B4, 18.08.2004, =D0=B2 15:33, Jan Wieck =D0=BF=D0=B8= =D1=88=D0=B5=D1=82: > Meaning that not enforcing the uniqueness of those columns isn't an=20 > option. The thing is that the columns _are_ unique, there's just no unique constraint on them. They are unique because there's a unique constraint on a subset of these columns. So no additional uniqueness enforcing needed. --=20 Markus Bertheau