Re: Entity vs. Table
Date: 14 Jun 2004 06:27:05 -0700
"Alan" <alan_at_erols.com> wrote in message news:<2ittqgFqitf3U1_at_uni-berlin.de>...
> It's not a requirement, but it is a starting point. If you start with a 3NF
> physical model, you can denormalize for the sake of performance.
Physical designs can't be 3NF. Normalization only applies to the logical level.
> > A TRY :
> > Physical datamodel is a model of the
> > database implementation ? (The databasemodel).
> > (Can contain redundancy does not have to be like the
> > logical datamodel, but MUST implement the logical model).
> Yes and no. There should be no redundancy
>, or it is not a propely
> implemented 3NF relational database. Otherwise, yes.
3NF has nothing to do with the physical level.
> Yes, with one small change. An ERD is a conceptual business model of the
> data and the realtionships(associations) among the data.
It is very incomplete and often leads to bad designs.
Alfredo Received on Mon Jun 14 2004 - 15:27:05 CEST