On Wed, Dec 23, 2020 at 7:15 AM Hou, Zhijie <houzj.f...@cn.fujitsu.com> wrote: > > Hi > > I have an issue about the parallel-safety checks. > > If target table is foreign table or temporary table, > rel_max_parallel_hazard_for_modify will return PROPARALLEL_UNSAFE, > which not only disable parallel insert but also disable underlying parallel > SELECT. > > +create temporary table temp_names (like names); > +explain (costs off) insert into temp_names select * from names; > + QUERY PLAN > +------------------------- > + Insert on temp_names > + -> Seq Scan on names > +(2 rows) > > I may be wrong, and if I miss sth in previous mails, please give me some > hints. > IMO, serial insertion with underlying parallel SELECT can be considered for > foreign table or temporary table, > as the insertions only happened in the leader process. >
I don't think we support parallel scan for temporary tables. Can you please try once both of these operations without Insert being involved? If you are able to produce a parallel plan without Insert then we can see why it is not supported with Insert. -- With Regards, Amit Kapila.
