Renan Alves Fonseca <renanfonseca(at)gmail(dot)com> writes:
> I'll assume that the silence about allowing GROUP BY means it is not a
> great idea...
Well, you can do grouping, ordering, or whatever else you want to the
result of the recursive WITH in the outer query level. I don't see
any advantage in allowing an additional level of that inside the WITH.
regards, tom lane