On 2016-10-19 09:43:10 +0530, Dilip Kumar wrote: > On Tue, Oct 18, 2016 at 1:42 AM, Robert Haas <robertmh...@gmail.com> wrote: > > But what's the impact on performance? Presumably parallel bitmap heap > > scan was already slower than the non-parallel version, and that commit > > presumably widens the gap. Seems like something to worry about... > > I have checked the performance in my local machine and there is no > impact on the gap.
Try measuring with something more heavy on bitmap scan time itself. E.g. SELECT SUM(l_extendedprice) FROM lineitem WHERE (l_shipdate >= '1995-01-01'::date) AND (l_shipdate <= '1996-12-31'::date); or similar. The tpch queries don't actually spend that much time in the bitmapscan itself - the parallization of the rest of the query is what matters... Greetings, Andres Freund -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers