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: Entity vs. Table

Re: Entity vs. Table

From: Alan <alan_at_erols.com>
Date: Thu, 17 Jun 2004 12:48:23 -0400
Message-ID: <2je0aqF104437U1@uni-berlin.de>

"Alfredo Novoa" <alfredo_at_ncs.es> wrote in message news:40d1baa0.14945460_at_news.wanadoo.es...
> On Thu, 17 Jun 2004 09:17:50 -0400, "Alan" <alan_at_erols.com> wrote:
>
> >> It is perfectly valid to have redundancy in the physical tables.
> >
> >Yes, if you denormalize to less than 3NF.
>
> No, you don't catch this.
>
> You can have a 5 or 6NF logical design and to have a lot of redundancy
> in the physical structures.
>
> On the other hand you can have a 5 or 6NF logical design and to have a
> lot of redundancy in the logical tables (aggregated tables for
> instance).
>
> It seems you don't understand the difference between the physical and
> the logical levels.
>
> > This is done often for performance
> >purposes, or ease of reporting, as well as some other reasons. But the
> >argument was about 3NF and redundancy.
>
> Normal forms have nothing to do with redundancy in the physical
> structures and they also allow redundancy in the logical level.
>
> With a good DBMS you could introduce redundance for performance
> purposes without affecting the 5NF design.
>
> >I guess the often ranked number 1 university in the U.S. (by U.S. News &
> >World Report) in I.S. grad programs is wrong and you are right.
>
> I don't know what university is, but it is rather probable that your
> guess is right.
>

I give up. Received on Thu Jun 17 2004 - 11:48:23 CDT

Original text of this message

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