Received: from localhost (postgresql.org [64.49.215.8]) by postgresql.org (Postfix) with ESMTP id 19533475F1A for ; Fri, 1 Nov 2002 15:53:41 -0500 (EST) Received: from cypress.adhesivemedia.com (cypress.adhesivemedia.com [207.202.159.72]) by postgresql.org (Postfix) with ESMTP id 64BEB475EBD for ; Fri, 1 Nov 2002 15:53:40 -0500 (EST) Received: from cypress.adhesivemedia.com (localhost [127.0.0.1]) by cypress.adhesivemedia.com (8.12.3/8.12.3) with ESMTP id gA1KrTFk009850; Fri, 1 Nov 2002 12:53:29 -0800 (PST) (envelope-from philip@adhesivemedia.com) Received: from localhost (philip@localhost) by cypress.adhesivemedia.com (8.12.3/8.12.3/Submit) with ESMTP id gA1KrTCq009847; Fri, 1 Nov 2002 12:53:29 -0800 (PST) X-Authentication-Warning: cypress.adhesivemedia.com: philip owned process doing -bs Date: Fri, 1 Nov 2002 12:53:29 -0800 (PST) From: Philip Hallstrom To: Josh Berkus Cc: Wei Weng , Subject: Re: Does this matter? In-Reply-To: <200211011223.48962.josh@agliodbs.com> Message-ID: <20021101125052.Y6303-100000@cypress.adhesivemedia.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Virus-Scanned: by AMaViS new-20020517 X-Archive-Number: 200211/13 X-Sequence-Number: 171 > Wei, > > > Does it make a performance difference if I use a char(20) or a char(36) > > as the primary key? My thought is no, but I would like to hear more > > opinions. > > Yes, it does, though probably minor unless you have millions of records. CHAR > is padded out to the specified length. Therefore the index on a char(36) > column will be a little larger, and thus a little slower, than the char(20). > Really? According to this url (search for "Tip") there is no performance difference just a space difference. I don't know for sure either way, but if there is a difference the manual needs updating. http://www.postgresql.org/idocs/index.php?datatype-character.html -philip