Re: Database-valued attributes?

"Paul Vernon" <paul.vernon_at_ukk.ibmm.comm> wrote in message news:boqjj0$18lk$1_at_gazette.almaden.ibm.com...
>
> Just need to agree on what a database value actually is. If it is a 'set of
> relations' what happens if two relations contain the same set of tuples (of
> the same type), but have different 'relation names'? Are they different
> relations?

Well, if you have two "top level" relvars in a database with exactly the same contents but different names, is that any problem? I'm not aware of any problems. I would say "yes, they are different relations."

Consider: we create a relation var "Primes" for interesting prime numbers we've calculated, and a relvar "Perfect" for interesting perfect numbers we have calculated. We're just about to run the applications that will be filling these relvars, so they're both currently empty. So they have the same set of tuples of the same type, but are different relvars.

> If so does that mean that if *relation variables* have names,
> then *relation values* must also have names? I.e. I suggest that either
> neither relation values and relation variables have names, or that both do.
> I suggest we cannot have either-or.
>
> :-)

I guess I'm not following you. Maybe the smiley means you're being funny? But I don't get the humor.

Perhaps I'm just in overly-literal mode today.

Marshall Received on Tue Nov 11 2003 - 17:16:11 CET