Re: Foreign key problem

From: Erwin <e.smout_at_myonline.be>
Date: 14 Jun 2006 01:18:15 -0700
Message-ID: <1150273095.922557.173400@u72g2000cwu.googlegroups.com>

> At the end of the day, foreign keys is an implementation issue. But Ted
> Codd had a lot to say about the domain of foreign keys. The "glue".

???????

Foreign keys (or better : the referential integrity rules that embody FKs) are an implementation issue to those writing DBMS's. They are very much a model issue to those writing applications that use a DBMS.

So whether or not they are an implementation issue does not depend on the hour of the day.

Date and Darwen still have a lot to say about foreign keys, and since that is based on over thirty years of additional research and the corresponding increased insights in the matter, their writings are now far more relevant than are Codd's. Incidentally : they have absolutely *nothing* to say about *the domain* of foreign keys, because they have nothing to say about the domain of attributes in general. Received on Wed Jun 14 2006 - 03:18:15 CDT