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Home -> Community -> Usenet -> comp.databases.theory -> Re: Counting propositions
"Paul G. Brown" <paul_geoffrey_brown_at_yahoo.com> wrote in message
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> > 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 ?
>
> Given that all relvars have a key, and assuming that your '*' is a
> macro that expands to 'all attributes' (don't matter what phase of
> query processing), then nr is going to equal the number of tuples in
> the relvar.
Ok. But why there is a need to know this number ? It is like saying "today I made 100 affirmations".
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