On Mon, 14 Jun 2004, Tom Lane wrote:
> "Jaime Casanova" <el_vigia_ec@hotmail.com> writes:
> > AND
> > CPA.cur_paralelo = ALL (SELECT cur_paralelo FROM aca_t_curso ...)
>
> Wait a second ... we are all overthinking the problem. The subselect
> returns three *different* values. It is not possible for any
> CPA.cur_paralelo values to be simultaneously equal to all three.
> So this test certainly fails at every row of CPA.
>
> Perhaps you meant "= ANY"?
I think what he wants is to output distinct sets of output columns where
for each of these sets of output columns there exists a set of rows that
meet the other conditions and that the set of cur_paralelo values for
that set of rows is the same as (or perhaps is a superset of) the set of
values returned from the subselect.