Re: Character string relation and functional dependencies
Date: Tue, 11 Dec 2007 12:37:31 -0800 (PST)
Message-ID: <10f55733-a741-4db7-95f8-eca69c7648f3_at_s19g2000prg.googlegroups.com>
On Dec 11, 11:29 am, "V.J. Kumar" <vjkm..._at_gmail.com> wrote:
> Tegiri Nenashi <TegiriNena..._at_gmail.com> wrote innews:f7283774-a81f-417a-9942-ca25012ff6d3_at_i29g2000prf.googlegroups.com:
>
> > On Dec 11, 6:08 am, "V.J. Kumar" <vjkm..._at_gmail.com> 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 !