Re: Is relational theory incomplete?

Tom,

The catalog in an rdbms is entirely meta-data and is a rich source of meta-data. Goedel's proof basically states that the conceptual level of discourse is necessary, which does not in any way invalidate any part of a logical data model.

The combination of conceptual, logical and physical is complete. The relational model is the best known logical data model, and it specifically limits itself to the logical level of discourse for important reasons like separation of concerns.

Regards,
Bob

"Tom Hester" <tom_at_metadata.com> wrote in message news:f488$3fafcb95$45033832$28183_at_msgid.meganewsservers.com...
> Gödel's proof is of the incompleteness of arithmetic, not relational
algebra
> (or calculus, or...). Essentially, Gödel demonstrated that a theory of
> arithmetic must contain at least one intensional statement of the form:
> 'this sentence is false'.
>
> Arithmetic had always been assumed to be purely extensional. Codd's
> relational theory was purely extensional. Remember all of the early
caveats
> on relational theory of the form 'first order function free'. Those
caveats
> were to insure that the theory was only extensional. To put it in other
> words, it only dealt with sets of things in the real world. A relational
> model is a first order description of some subset of the real world.
>
> The cost of this purely extensional restriction is the almost total lack
of
> metadata information available in a relational system.
>
> "mountain man" <hobbit_at_southern_seaweed.com.op> wrote in message
> news:xJzrb.4373$aT.2467_at_news-server.bigpond.net.au...
> > Did Date ever make reference to Godel's
> > incompleteness theorem? If so, how did
> > he handle it?
> >
> > How does relational theory come to terms
> > with Godel's incompleteness theorem?
> >
> >
> >
> >
> >
> > Farmer Brown
> > Falls Creek
> > OZ
> > www.mountainman.com.au
> >
> >
> >
>
>
Received on Mon Nov 10 2003 - 19:44:04 CET