Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Usenet -> comp.databases.theory -> Re: c.d.theory glossary - RELATION

Re: c.d.theory glossary - RELATION

From: x <x-false_at_yahoo.com>
Date: Fri, 30 Apr 2004 18:01:21 +0300
Message-ID: <4092698a@post.usenet.com>

"mAsterdam" <mAsterdam_at_vrijdag.org> wrote in message news:40925ec4$0$574$e4fe514c_at_news.xs4all.nl...
> x wrote:
> > Laconic2 wrote:
> >>I would have said that "An entity is DESCRIBED BY a set of attributes."
> >>
> >>I think REPRESENTED is too strong.
> >
> > It was not my choice.
> > As I said, I found that on a web page about ER modeling.
> >
> > Do you also think REPRESENTED is too strong in the context of
> > relational model (not in the context of ER modeling) ?
>
> This is where a difference come in:
>
> In ER-modelling the parts of the model are
> abstractions of (real or fantasized) world _things_
> and associatons between them, vs.
> the relation values in a relational model represent _facts_
> (or beliefs) about a (real or fantasized) world.
>
> In short
> RM.REPRESENT yes, *facts*.
> ER.REPRESENT yes, *things*.
>
> Just 2 Ec in trying to make sense of this mess.

If you look in a dictionary you'll find:  Fact: someTHING that exists (or happened).

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

Received on Fri Apr 30 2004 - 10:01:21 CDT

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US