Re: Character string relation and functional dependencies

From: Jan Hidders <hidders_at_gmail.com>
Date: Mon, 10 Dec 2007 09:49:17 -0800 (PST)
Message-ID: <f2db5eb0-d13b-48fc-aaf4-ac670b751416_at_d21g2000prf.googlegroups.com>


On 10 dec, 02:09, "V.J. Kumar" <vjkm..._at_gmail.com> wrote:
> Jan Hidders <hidd..._at_gmail.com> wrote innews:dd39930a-d971-43a1-8d13-779cd635f632@s8g2000prg.googlegroups.com:
>
>
>
> > On 7 dec, 01:24, Tegiri Nenashi <TegiriNena..._at_gmail.com> wrote:
> >> On Dec 6, 2:38 pm, Jonathan Leffler <jleff..._at_earthlink.net> wrote:
>
> >> > Tegiri Nenashi wrote:
> >> > > On Dec 6, 9:40 am, rp..._at_pcwin518.campus.tue.nl (rpost) wrote:
> >> > >> Another difference is that database tables are finite and
> >> > >> variable,
>
> >> > > Oh, relations in database world are certainly not restricted by
> >> > > finite cardinality.
>
> >> > I thought that computers are finite, so the relations containable
> >> > in them are too - even if damn large. There's a big difference
> >> > between very large and infinite.
>
> >> This doesn't really matter. You can still reason about infinite
> >> relations with finite resources available on you computer platform.
>
> > Indeed you can. In case anyone is interested in a concrete example:
>
> This kind of "reasoning" is an illusion. The constraint database the
> link refers to works with a finite set of first-order formulas ("extended
> tuples") that permit quantifier elimination rather than with a finite set
> of actual tuples as the relational model would. It is a simple
> observation that a first-order formula under certain conditions can
> "represent" a possibly infinite set. However, formula-set
> interpretation happens in the user brain only, not in the database
> itself as would be the case with the traditional relational model [...]

Come on, V.J., I'm quite sure that you can make much more interesting contributions to this newsgroup than this kind of quibbling. Please don't let your ego cloud the brightness of your mind.

  • Jan Hidders
Received on Mon Dec 10 2007 - 18:49:17 CET

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