On Tue, Jun 14, 2016 at 2:16 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > > Robert Haas <robertmh...@gmail.com> writes: > > In practice, we don't yet have the ability for > > parallel-safe paths from subqueries to affect planning at higher query > > levels, but that's because the pathification stuff landed too late in > > the cycle for me to fully react to it. > > I wonder if that's not just from confusion between subplans and > subqueries. >
Won't the patch as written will allow parallel-restricted things to be pushed to workers for UNION ALL kind of queries? Explain verbose Select * from (SELECT c1+1 FROM t1 UNION ALL SELECT c1+1 FROM t2 where c1 < 10) ss(a); In above kind of queries, set_rel_consider_parallel() might set consider_parallel as true for rel, but later in set_append_rel_size(), it might pull some unsafe clauses in target of childrel. Basically, I am wondering about the same problem as we discussed here [1]. [1] - https://www.postgresql.org/message-id/CAA4eK1Jz5tG2D2PCNYqYob2cb4dKowKYwVJ7OmP5vwyRyCMx4g%40mail.gmail.com With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
