I wrote:
> Yeah. That's a hangover from an ancient decision that sort/limit
> would always be applied at the top of the plan tree. I'm too
> lazy to check the details right now, but I think we already relaxed
> that in some cases (or maybe it was about evaluating stuff
> before/after GROUP BY?).
Ah, right: see make_sort_input_target() and its very extensive
comment in planner.c. I wonder why that didn't trigger in
your example.
regards, tom lane
