Re: Objects and Relations

On Feb 26, 3:59 pm, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
> Alfredo Novoa wrote:
> > On 24 feb, 13:43, "Cimode" <cim..._at_hotmail.com> wrote:
>
> >>If you define class by domain then what is the RM equivalent for
> >>relation?
>
> > You probably mean the OO equivalent for relation.
>

> > OO lacks an equivalent for relation. That's why it is so difficult to
> > write database applications using OO languages.
>
> >>In RM, a domain is *not* the same* as a type or a relation.
>
> > In RM domain is used as a synonym of type and it is completely
> > different to relation.
>
> The above is arguable and depends on one's definitions for domain and
> type. Specialization by constraint makes them essentially synonymous.
>
>
>
> >>(
> >>domain = set of *possible* values for which a relation draws
> >>*possibly* values
>
> > When you say "relation" we assume that you mean "relation value". If
> > you mean "relation variable" please write: "relation variable" or
> > "relvar".
>
> > On the other hand, a domain is a set of any kind of values: scalar,
> > relational, tuple, array, etc.
>
> >>typing = making a domain from a relation body and name (therefore
> >>only *existing* values for a specific relation).
>
> > I don't see any sense here.
>
> As usual, Cimod uses a definition derived solely from his own imagination.
That would suppose that in the first place, I was trying to establish a new definition...In this case the intent was simply into summarizing in one sentence important concepts for communication purposes with Alfredo Novoa.

Once again, BB attempts to draw the discussion to conflict. He does not miss one occasion to point out errors in others but never applies such treatment to himself. Classical worthless immature and hyppocrit attitude. Received on Mon Feb 26 2007 - 16:24:27 CET