Re: Views for denomalizing

On Wed, 2 Feb 2005 22:34:40 -0600, "Dawn M. Wolthuis" <dwolt_at_tincat-group.comREMOVE> wrote:

>1) SQL-DBMS's (at least those that conform to SQL92) provide no constraints
>on the user creating new tables to restrict base tables from being
>denormalized EXCEPT in the case of the first normal form.

But SQL allows the definition of table variables that does not fulfill the prerequisites for being in 1NF (nulls and duplicates).

>1NF is the only normal form that is forced upon us by many common industry
>tools.

So this is wrong.

>Yet SQL-DBMS's and
>related tools consider it so much more important than the other normal forms
>that even in the views, where denormalization is common, acceptable, and
>clearly useful, non-1NF is still not (typically, as best I can tell)
>employed.

And this is wrong too.

> But
>we as a profession will need to attend to those who already graduated to
>eliminate the bias against lists within attributes, at least when it comes
>to views of the data, if not base relations.

Lists within attributes break the Information Principle, the most fundamental principle of the Relational Model.

Regards Received on Fri Feb 04 2005 - 15:03:08 CET