Re: By The Dawn's Normal Light

From: Alfredo Novoa <alfredo_at_ncs.es>
Date: Fri, 22 Oct 2004 11:23:19 GMT
Message-ID: <4178ed91.92089859_at_news.wanadoo.es>


On Thu, 21 Oct 2004 16:20:36 -0400, "Laconic2" <laconic2_at_comcast.net> wrote:

>The two rules I proposed were A) the no duplicates rule, and B) the atomic
>values rule. These, taken together make up 1NF.
>
>But if 1NF is defined on RELATIONS, not TABLES, part A above is
>superfluous. A RELATION is, by definition, a set. In a set, different
>elements are always distinct. The no duplicates rule is inherent in the
>definition of a set.

And partB is wrong, thus 1NF is superfluous.

>So here's the rephrasing I'm proposing:
>
>Zero Normal Form:

>The columns that make up a candidate keys must have no missing (NULL)
>Values,

Neither the rest of the columns.

>First Normal form:
>
>A Relation is in first normal form if and only if none of the domains of its
>attributes permit compound or multivalued values.
>
>(At least I think that's right).

That's wrong. It should be: A relation is in First Normal Form.

1NF is superfluous.

Regards Received on Fri Oct 22 2004 - 13:23:19 CEST

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