Robert Haas <robertmh...@gmail.com> writes: > On Tue, May 3, 2022 at 2:13 PM Tom Lane <t...@sss.pgh.pa.us> wrote: >> In any case, fundamental redesign of what EXPLAIN prints is a job >> for v16 or later. Are you okay with the proposed patch as a v15 fix?
> Yes. I can't really vouch for it, but I don't object to it. I re-read the patch and noticed that I'd missed one additional change needed: - run_cost = cpu_per_tuple * baserel->tuples; + run_cost = cpu_per_tuple * path->subpath->rows; That is, we should estimate the number of qual evaluations and cpu_tuple_cost charges based on the subpath row count not the non-parallel-aware relation size. So this reduces the cost of the SubqueryScan itself, as well as its row count, in partial paths. I don't see any further change in regression test results though. Pushed with that change. regards, tom lane