Re: Can we solve this -- NFNF and non-1NF at Loggerheads

"Dawn M. Wolthuis" <dwolt_at_tincat-group.comREMOVE> wrote in message news:cu2llf$jq3$1_at_news.netins.net...
> "Alan" <alan_at_erols.com> wrote in message
> news:36htmvF54uqs0U1_at_individual.net...
> <snip>
> > Nothing has changed. 1NF means (and has always meant) that all values
are
> > atomic (simple, indivisible),
>
> This would put you in a separate camp from Date (and Alfredo). Many
> relational theorists today have given up on the atomin/scalar concept.
Any
> attempt to define these relates them to the domain for the type. As soon
as
> you can have user-defined types, then you can have a list meet a
definition
> of "atomic" for an attribute with lists as the domain.

Yes. And as soon as you do, it is no longer in 1NF.

 You should be able
> to find plenty of information on this at dbdebunk.com, for example.
>
> > and any value must be a single value from the
> > domain of that attribute (E.g., if the attribute is date_of_birth, then
> > the
> > value must be a date_of_birth, not a hire_date or last_name). It does
not
> > allow nested data.
> > It does not allow multi-valued or composite attributes.
>
> Are you not familiar with relation-valued attributes?
>

As mentioned below, Oracle supports this concept (VARRAYS, Nested Tables), but then you are not in 1NF. Big deal.

> > It is very simple. It has been explained. Oracle, (and other RDBMSes)
> > support NFNF, in that they have constructs for nested tables, varying
> > arrays
> > and other "relation within relation", or "collection" situations.
>
> Yet many continue to believe and teach the old version of 1NF (from before
> the definition was changed to say that if you have a relation, then it
must
> be in 1NF by definition). Even you seem to be retaining that old
> definition, which requires you to make 1NF an axiom since it cannot be
> derived from even such non-obvious statements as the relational
information
> principle. If folks had not redefined the term, but rather spread the
word
> that 1NF (as it was defined, in terms of scalar values) is now dead, the
> industry would likely move forward faster in this particular area. That
> would have been a significant blow to relational theory, however, so it
was
> handled more quietly, hoping not to rock the boat (I'm guessing).
>
> --dawn
>

You remind me of someone who keeps changing from psychiatrist to psychiatrist until finding one that tells you what you want to hear. Congratulations, you found Dr. Alfredo Novoa. I'm done. I only wish I never got into this again with you from last year. I never learn. Maybe this time. You know what, if you could please do me a favor? Stop me next time. Received on Sun Feb 06 2005 - 02:56:44 CET