David Rowley <dgrowleyml@gmail.com> writes:
> As for fixing it; testing for a Const-false havingClause can't be done
> as that only works for this case which const-folding happens to figure
> out during planning. You could equally have something Var-less like:
Yeah, I don't think the havingClause being constant-false is the
key point here. I've not looked closely at 67a54b9e, but I suspect
that anything Var-free is potentially an issue. Or it might even
fail for something that has Vars but is non-strict.
The core of the problem though is that the aggregation node will
issue an all-nulls row that did not come from its input, and we
have to be sure that the HAVING clause is properly evaluated
for that row.
regards, tom lane
