You point out, with painful illustration, the "achilles heel" of using migrated primary keys in database design: the keys can multiply rapidly, making it very tiresome to construct "join clauses".

But as my article points out, you lose the relational database's capability of enforcing powerful "business rules" such as the Unification Rule, as I illustrate in my article.

Here is an article that explains and illustrates the Unification Rule. The article was written by a data modeling guru, Bert Scalzo (chief architect of the popular TOAD data modeling product):

http://www.toadworld.com/LinkClick.aspx?fileticket=hZvoqN6j0js=&tabid=321

Marvin Elder