Re: one-to-one

Michael,

> Thanks Josh, Jason and Adrian for your comments!
> Josh, I'm curious why you refer to a "pseudo-relational model"?

Well, SQL is a very imperfect implementation of relational theory.  SQL fails
to implement a lot of Codd's relational calculus, such as distributed keys
and database constraints, as well as making some set operations (such as "is
not a member of" and "is the greatest(col) record of") far more difficult and
inefficient than they need to be.

For more detail on this, see Fabian Pascal's web page, particularly the
articles written by CJ Date:
www.dbdebunk.com

--
-Josh Berkus
 Aglio Database Solutions
 San Francisco