Re: Functional Dependencies > Uniqueness Constraints

Marshall wrote:
>
> ... (And of course there must be a rule that
> says every base table must have at least one functional
> dependency in which the union of the determinant set
> and the dependent set equals the set of attributes. (This
> restriction is sufficient to ensure every base table is a
> relation; is it necessary?))
> ...

I would say not necessary. If a table is a representation of a relation, then I`d think that even if no rule is stated, by definition the union of the attributes is a CK, eg., if there is no stated determinant set, all the attributes are in the dependent set. I can`t think why one would want to state this, shouldn`t a dbms assume itÉ

p Received on Wed Aug 30 2006 - 19:35:20 CEST