On Thu, May 27, 2021 at 1:03 PM tsunakawa.ta...@fujitsu.com <tsunakawa.ta...@fujitsu.com> wrote: > > From: houzj.f...@fujitsu.com <houzj.f...@fujitsu.com> > > Although, the 4 workers case still has performance degradation compared to > > serial case. > > > > SERIAL: 58759.213 ms > > PARALLEL 2 WORKER [NOT SKIP FSM]: 68390.221 ms [SKIP FSM]: > > 58633.924 ms > > PARALLEL 4 WORKER [NOT SKIP FSM]: 67448.142 ms [SKIP FSM]: > > 66,960.305 ms > > Can you see any difference in table sizes?
Also, the number of pages the table occupies in each case along with table size would give more insights. I do as follows to get the number of pages a relation occupies: CREATE EXTENSION pgstattuple; SELECT pg_relpages('test'); With Regards, Bharath Rupireddy. EnterpriseDB: http://www.enterprisedb.com