Re: pro- foreign key propaganda?

David Cressey wrote:
...
> Well, as you've said more than once, the concept of primary key doesn't
> exist at the RDM level of abstraction. ...

Maybe not "primary key" but the idea of a key is certainly inherent in the RDM assuming you will admit 'rename' plus the original operators natural join, select and project, to it.

(Heh, the first time I saw that "aref" tag in HTML, I thought "good for them, they've lifted a useful idea of Codd's from twenty years ago and generalized it to a mere reference"! Then I realized there was no "aref constraint", so the author doesn't have an inherent way to make the html stick. The bind is so late that only the user knows - weird!) Received on Tue May 20 2008 - 00:19:00 CEST