From: Date: December 22 2005 3:08am Subject: Re: Are primary keys essential? List-Archive: http://lists.mysql.com/mysql/193150 Message-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Thanks the on & off-list replies, but I obviously didn't explain my situation very well! My app is essentially creating summary reports from large amounts of data. It is _not_ doing the actual data warehousing. It's international trade data. The data tables contain foreign keys for stuff like destination country, trade commodity category etc., but they are _not_ themselves referenced by any other table. Therefore I have not yet found, nor do I envisage finding, any use for an arbitrary auto_increment primary key. So why would/might I need a PK at all? TIA, James Harvard