Re: A Normalization Question

From: Paul Vernon <paul.vernon_at_ukk.ibmm.comm>
Date: Tue, 13 Jul 2004 12:07:24 +0100
Message-ID: <cd0g13$kea$1_at_gazette.almaden.ibm.com>


"Christopher Browne" <cbbrowne_at_acm.org> wrote in message news:2lh84eFcbvkeU1_at_uni-berlin.de...
[snip]
> > With respect to dbs, normalization is the process of eliminating or
> > replacing duplicate (redundant) things with a reference to the
> > original thing being represented. If one interprets it as treating
> > redundancy and normalization as the same thing, one is correct (in
> > their own mind).
>
> No, normalization is a _two_-fold process.
>
> 1. It is a process of eliminating redundant data. Not of "replacing
> things with references," but of _eliminating redundant data_.
>
> 2. It is also a matter of making sure that data dependancies make
> sense.

Surly that second process is something to do with 'business modelling' and nothing to do with the mathematical concept of normalisation. The fact that many users use the term to include that second process is a confusion on their part and symptomatic of general confusion about database theory.

> If it was true to say that "normalization" meant "eliminating
> redundancy," then it would make sense to not bother using the word
> normalization, as it, itself, is redundant. Far simpler to say
> "eliminating redundancy," as that more clearly says what was intended.

Well, it might be far simpler, but it wouldn't sound quite so impressive would it? ;-)
Anyway as Jan has pointed out "eliminating redundancy" might capture the idea informally, but more formal treatment requires more precision, and I guess giving the topic a specific name like Normalisation helps indicate that there is a little more to it than just "eliminating redundancy", even if it is arguable.

Regards
Paul Vernon
Business Intelligence, IBM Global Services Received on Tue Jul 13 2004 - 13:07:24 CEST

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