Hi, At Sun, 02 Apr 2017 16:30:24 +0300, Konstantin Knizhnik <k.knizh...@postgrespro.ru> wrote in <58e0fcf0.2070...@postgrespro.ru> > Hi hackers and personally Robet (you are the best expert in both > areas). > I want to ask one more question concerning parallel execution and FDW. > Below are two plans for the same query (TPC-H Q5): one for normal > tables, another for FDW to vertical representation of the same data. > FDW supports analyze function and is expected to produce the similar > statistic as for original tables. <big explain> > The plans look very similar, but first one is parallel and second - > not. > My FDW provides implementation for IsForeignScanParallelSafe which > returns true. > I wonder what can prevent optimizer from using parallel plan in this > case?
Parallel execution requires partial paths. It's the work for GetForeignPaths of your FDW. regards, -- Kyotaro Horiguchi NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
