Re: Entity vs. Table

From: Alan <alan_at_erols.com>
Date: Mon, 14 Jun 2004 11:05:34 -0400
Message-ID: <2j5t5nFtq4a6U1@uni-berlin.de>

"Alfredo Novoa" <alfredo_at_ncs.es> wrote in message news:40cdb944.19049702_at_news.wanadoo.es...
> On Mon, 14 Jun 2004 09:16:27 -0400, "Alan" <alan_at_erols.com> wrote:
>
>
> >You start with business requirements, which you turn into an ERD. You
then
> >follow the rules referred to above, to turn it into an actual relational
> >schema. This is the physical model.
>
> Very very wrong!!
>
> This is the logical model!
>
>
> Regards
> Alfredo

I think we are really in agreement, but the use of wrods and relative point-of-view is getting in the way. Your view is certainly correct. Much of the confusion stems from the use of the term "model", which means different things to different people. So, how about this... (note that "model" is not used!)

The basic divisions are:

Business Requirements
flows to
Conceptual Design (ERD or other)
flows to
Logical Design (Mapping to Relational Schema (tables)) flows to
Physical Design (Indexes, Storage Structures, and other RDBMS-independent items) Received on Mon Jun 14 2004 - 10:05:34 CDT