It looks to me like set_append_rel_pathlist builds a partial path for an appendrel only if there exist partial paths for all members of the appendrel. I don't understand this restriction. Why could you not build it from a regular path for each appendrel child? You'd have to farm out entire childrels to workers, which might be larger chunks of work than one could wish, but it seems better than failing to parallelize at all.
regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers