On Tue, Mar 7, 2017 at 5:16 AM, Dilip Kumar <dilipbal...@gmail.com> wrote: > I am confused about whether to call > "get_cheapest_parallel_safe_total_inner" with > innerrel->cheapest_parameterized_paths like we do in case of > hash_inner_and_outer or with > innerrel->pathlist. The reason behind I am calling this with complete > pathlist (innerrel->pathlist) is that inside generate_mergejoin_paths > it calls "get_cheapest_path_for_pathkeys" for complete pathlist and if > we decide not to call consider_parallel_mergejoin if the cheapest > parallel safe path in innerrel->cheapest_parameterized_paths is NULL > then it will not be fair (we might have some parallel safe paths in > innerrel->pathlist).
You're right to be confused, because that seems to be a bug in the existing code. There seems to be no guarantee that the cheapest parallel-safe path will be in the cheapest_parameterized_paths list. I'll go fix that. As a matter of style, when testing a value of type "bool", write if (x) or if (!x). When testing a variable of some other type, say int, write if (x == 0) or if (x != 0) or whatever. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
