Re: Character string relation and functional dependencies

From: Tegiri Nenashi <>
Date: Tue, 11 Dec 2007 12:37:31 -0800 (PST)
Message-ID: <>

On Dec 11, 11:29 am, "V.J. Kumar" <> wrote:
> Tegiri Nenashi <> wrote
> > On Dec 11, 6:08 am, "V.J. Kumar" <> wrote:
> >> The formulas look very cute, no doubt about that, but immediate
> >> questions are:
> >> how do you propose to index infinite relations ?
> > First, let's establish the idea that an index for a finite relation
> > R(x,y) is a function.
> First of all, if you introduce the arbitrary function as an additional
> primitive, deus ex machina as it were, then in many cases you do not
> need any of the finitely definable infinite relation apparatus. SQL
> already has built-in or user-defined functions that make possible
> evaluating queries over a finite tuple domain with embedded infinitary
> structures. You need to try and express query evaluation in your model
> with relations only -- that's the whole point !

Well, in traditional databases index structures are auxiliary. Likewise, I would like to keep functions hidden. After all there is one relation

x + y = z

but there are three functions that can index it.

Anyway, this whole sub thread is a digression off the initial thought about connection between objects and relations on one hand, and object methods and functional dependencies on the other. I'm surprised nobody objected the idea (pun intended) that object corresponds to the relation, and not relation attribute.

In a word, are computers finite machines? Yes. Does it necessarily restrict relations (and other structures) to be be finite ones? Not necessarily. I suggest to close this rather unsophisticated discussion. Received on Tue Dec 11 2007 - 21:37:31 CET

Original text of this message