"Steinar H. Gunderson" <sgunderson@bigfoot.com> writes:
> Any good ideas why 8.1 would refuse to do this, when 7.4 would do it? It does
> not matter how high I set my work_mem; even at 2.000.000 it refused to hash
> the subplan.
AFAICS, subplan_is_hashable() is testing the same conditions in 7.4 and
HEAD, so this isn't clear. Want to step through it and see where it's
deciding not to hash?
regards, tom lane