Re: Counting propositions

"Laconic2" <laconic2_at_comcast.net> wrote in message news:RYKdnQ02bsxjNFDdRVn-vg_at_comcast.com...
>
> "x" <x-false_at_yahoo.com> wrote in message news:40cd9b6a_at_post.usenet.com...
>
> > If tuples in a relational relation(ship) (or relvar) are propositions,
> what
> > is the meaning of :
> >
> > select count(distinct *) as nr
> > from <relvar>
> >
> > and the like ?
>
> Before dealing with your question, we have to decode the intent behind
the
> wildcard.
>
> In particular, when does the wildcard get expanded to the list of all the
> columns? At compile time? at execution time?
>
> It makes a difference.

Why does it make a difference? Exotic operators aside (e.g. Pivot by Microsoft), could you give an example, simple select-project-join preferrably? Received on Mon Jun 14 2004 - 19:57:40 CEST