Re: wrong query result with jit_above_cost= 0

>>>>> "Dmitry" == Dmitry Dolgov <9erthalion6(at)gmail(dot)com> writes:

Dmitry> Yep, my bad, forgot to turn it on. Now I see what's the
Dmitry> problem, one of the null fields is screwed up, will try to
Dmitry> figure out why is that.

The handling of nulls in grouping set results is a bit icky, see
prepare_projection_slot in nodeAgg.c. The comment there lists a number
of assumptions which may or may not hold true under JIT which might give
a starting point to look for problems. (Unfortunately I'm not currently
in a position to test on a JIT build)

(This wasn't my first choice of approach; originally I had a GroupedVar
node that evaluated either as the Var would or to NULL instead, and put
that into the projection. However there was a lot of resistance to this
approach at the time, and the new node idea was abandoned in favour of
poking directly into the slot.)

--
Andrew (irc:RhodiumToad)