On Fri, 21 Dec 2018 at 06:26, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Pushed with some fiddling with the comment.
Great. Thanks!
> I wasn't excited about the test case you offered --- on HEAD, it pretty
> much all devolves to file access operations (probably, checking the
> current length of all the child relations). Instead I experimented
> with an old test case I had for a complex-to-plan query, and got these
> results:
oh meh. I forgot to mention I was running with plan_cache_mode =
force_generic_plan and max_parallel_workers_per_gather = 0. If you
tried without those then you'd have seen a massively different result.
Your test seems better, regardless.
--
David Rowley http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services