Re: Normalization and DBMS
Date: Wed, 12 May 2004 12:03:36 +0300
Message-ID: <40a1e7a4$1_at_post.usenet.com>
"Dawn M. Wolthuis" <dwolt_at_tincat-group.com> wrote in message
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> "x" <x-false_at_yahoo.com> wrote in message
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> > Codd 1970 ACM paper:
> > "A first-order predicate calculus suffices if the collection of
relations
> is
> > in normal form."
> > "Such a language would provide a YARDSTICK of linguistic power for all
> other
> > proposed data languages."
> >
> > Someone claimed in this group that normalization is not "good" .
> > How powerful is the data language of an (existing) DBMS not based on
> > "normalization" ?
>
> It is 1NF with which I disagree and all other normal forms are based on
> this. 2nd and 3rd normal forms (for example) are semantic and related to
> "functional dependencies" and they make a lot of sense for designing for
> minimizing the costs of the database over time as requirements change.
1NF
> is not based on semantics, but on a "guess" that making our mathematics
> simplest wrt to the language of the propositions/predicates would make the
> most sense. 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. In fact, the
> anecdotal evidence that I have seen (which could very well be skewed as I
> have done no scientific survey) is heavily skewed toward databases that
are
> not in 1NF.
>
> If you use Date's terminology, you need GROUP and UNGROUP operators in
your
> language. This could also be NEST and UNNEST. The language used with
PICK,
> for example, reads easier than SQL and includes such language as "WITH
> EVERY" so you get
>
> LIST STUDENTS WITH EVERY MAJOR <> "MATH"
>
> Did that answer the question? --dawn
No. PICK is an inferential or a non-inferential DBMS ? If it is an inferential DBMS, what logic does it use ? How this logic compare to first order logic in a RDBMS (in terms of linguistic power, not performance)
If it is not an inferential DBMS, how it manages to enforce data integrity ?
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