Re: Storing data and code in a Db with LISP-like interface

Marshall Spight wrote:
> Alvin Ryder wrote:
> > Marshall Spight wrote:
> >
> > > And anyway, I wouldn't say the RM is the best tool for
> > > *everything.* Just the best tool for data management.
> >
> > Only certain kinds of data, it's not very good for: temporal, spatial,
> > logic, oo, multimedia, unstructured and document libraries, ... but yes
> > it has some strengths too.
>
> The RM is a practical application of set theory. Is set theory
> good for some kinds of data but not others? Set theory
> is foundational. The analogy to what you are saying ("good
> for some things, not for others") would be like saying that
> some parts of a house need a foundation, but not others.
>
> What kinds of data can't you put in sets?
>
>
> Marshall

Hmm, yes and no.

The original RM was defined circa 1969/70 but was then extended by Codd (and others) many times and in many different directions. For instance in '79 Codd wrote "Extending the Relational Model to Capture More Meaning".

Why extend the RM if it was set in stone and never needed maturing?

He writes, "The intent is to capture (in a more or less formal way) more of the meaning of the data so that database design can become more systemetic and the database system itself can behave more intelligently ..."

But once we try to capture the "meaning" of data to provide more intelligence in the db, we enter a wide open never ending pursuit. Now we are not using sets in a blind way.

The areas I identified previously are widely accepted as worthy of such research and extension. Neither Codd nor peers have been idle in pursuit of bridging the sementic gaps. Of course it may be decades before the wider community and commercial systems catch up.

Cheers. Received on Mon May 01 2006 - 23:58:12 CEST