Hi, https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=spurfowl&dt=2018-04-05%2003%3A22%3A05
*** /home/pgbuild/buildfarm/HEAD/pgsql.build/src/test/regress/expected/select_parallel.out 2018-04-04 23:22:07.297108347 -0400 --- /home/pgbuild/buildfarm/HEAD/pgsql.build/src/test/regress/results/select_parallel.out 2018-04-04 23:24:11.709955623 -0400 *************** *** 103,109 **** ----------------------------------------------------- Finalize Aggregate -> Gather ! Workers Planned: 1 -> Partial Aggregate -> Append -> Parallel Seq Scan on a_star --- 103,109 ---- ----------------------------------------------------- Finalize Aggregate -> Gather ! Workers Planned: 3 -> Partial Aggregate -> Append -> Parallel Seq Scan on a_star This is the query like this: -- Disable Parallel Append alter table a_star reset (parallel_workers); alter table b_star reset (parallel_workers); alter table c_star reset (parallel_workers); alter table d_star reset (parallel_workers); alter table e_star reset (parallel_workers); alter table f_star reset (parallel_workers); set enable_parallel_append to off; explain (costs off) select round(avg(aa)), sum(aa) from a_star; I don't see why... -- Thomas Munro http://www.enterprisedb.com