Re: Database design, Keys and some other things

Marshall Spight wrote:
> mAsterdam wrote:
> > Marshall Spight wrote:
> > >
> > > However, there is a definite trap in this general area, which
> > > is the trap of thinking that there is anything profound to
> > > be said about the relationship between the internal and the
> > > external predicate. That relationship, between the database
> > > and the world it models, exists only in the minds of the users
> > > of the system, and it is wholly an illusion, if you will.
> > > This is an important point, and it is also a philosophical one.
> >
> > And both profound and relevant.
>
> I guess you're saying it's profound that there's
> nothing profound to be said about the relationship between
> internal and externa predicate. I guess I could buy that.

I'll admit I didn't read the entire thread to this point, and I won't claim profundity, but surely we can say many things about the relationship between the predicates we are modeling and the implementation model of those predicates.

If you start in the real world with an external predicate corresponding to a fact (or opinion ;-), you could classify instances when a lossy (rather than lossless) internal predicate is selected. We can look at instances when a single external predicate is mapped to multiple internal predicates. We can identify which data modeling techniques and models produce which variations in these mappings.

On the other hand, if you see the source of your propositions as associated with the internal predicate (and there are some database-centric thinkers that I'm guessing think about it that way) and you derive the external (the real world) proposition from that, then I've got nothing to say about the relationship between internal and external. If you want to derive the real world from a database, then I have no doubt profundity will be lacking.

Or did I miss the point? --dawn Received on Sat Oct 01 2005 - 23:17:24 CEST