Re: E/R modeling: relationship's attributes

paul c wrote:
> Mikito Harakiri wrote:
> > U-gene wrote:
> >
> >>... it tryes to describe some enterprise, its
> >>entitites, relationships ets, what exist in real world ...
> >
> >
> > Do you understand the difference between the model and the real world?
> >
> > (Prof Krasnoselsky used to puzzle his students with a linear control
> > system that was supposed to output the input signal shifted forth in
> > time -- predict the future in other words. After a humble student's
> > attempt to explain that such system would be unstable prof asked such
> > question. I interpret it as a retorical question that ends the
> > discussion.)
> >
>
>
> Could have been Prof. Raskelnikov for all I know, just kidding. It's
> certainly a rhetorical question and a darned good one IYAM. William
> Kent, widely-quoted practioner and writer (died recently, not exactly
> Codd's generation in years, but certainly the same DP generation) wrote
> this in the preface to his neat little book, "Data and Reality":
>
>
> "Along the way, we implicitly suggest a hypothesis (by sheer weight of
> examples, rather than any kind of proof -- such a hypothesis is beyond
> proof): there is probably no adequate formal modelling system.
> Information in its "real" essence is probably too amorphous, too
> ambiguous, too subjective, too slippery and elusive, to ever be pinned
> down precisely by the objective and deterministic processes embodied in
> a computer."
>
>
> more excerpts at: http://www.bkent.net/Doc/darxrp.htm
>
>
> It might be interesting if the OO/MV people would reference Kent's
> examples so that the rest of us could know exactly which one they're
> talking about at any particular time!
>
>
> p

A great book, and way ahead of its time. Went out of print for quite a while, to the detriment of the literature. Received on Thu May 04 2006 - 19:48:41 CEST