Re: Normalization and DBMS

From: Dawn M. Wolthuis <dwolt_at_tincat-group.com>
Date: Tue, 11 May 2004 17:07:47 -0500
Message-ID: <c7ris1$veq$1_at_news.netins.net>


"Leandro Guimarães Faria Corsetti Dutra" <leandro_at_dutra.fastmail.fm> wrote in message news:pan.2004.05.11.21.25.17.712587_at_dutra.fastmail.fm...
> Em Tue, 11 May 2004 15:09:12 -0500, Dawn M. Wolthuis escreveu:
>
> > That is the only logic I can find behind 1NF and I have found
> > absolutely NO and I mean NO emperical data to suggest that putting
> > data into 1NF helps minimize the cost of the system for the long
> > haul.
>
> 1NF was initially applied to clean our databases of such
> horrors as:
>
> CREATE TABLE
> (
> subject,
> year,
> grade_jan,
> grade_feb,
> ...
> )
> ;

Yes, oddly enough, such constructs are much more likely in a relational database simply because there is no ability to have a "real" repeating group for the grades (a little subtable within the table).

>
> These were known as repeating groups. Now there is a debate
> about nested tables which I haven't looked into properly. But I do
> maintain that getting rid of repeating groups is The Right Thing To
> Do, and one of the reasons why relational is so much better.
>
> Now feel free to trounce me... this post was lousy, I'm too
> lazy know to do anything formal enough.

No trouncing -- I'm too bummed by the last message I read from you. ;-) --dawn

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> Av Sgto Geraldo Santana, 1100 6/71 +55 (11) 5686 9607
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Received on Wed May 12 2004 - 00:07:47 CEST

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