Re: Normalization and DBMS

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"Leandro Guimaraes 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,
> ...
> )
> ;
>
> 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.

In addition, 1NF was initially applied to clean our databases of such "horrors" as:
 CREATE TABLE
 (
   ...,
   date(day/month/year),
   ...
 )
These were known as composite domains.
If you consider the active domain of a composite domain, it looks like a relationship.

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