Robert Haas <robertmh...@gmail.com> writes: > Another awkwardness of this patch is that it makes > create_append_path() and consequently set_dummy_rel_pathlist() take an > additional "root" argument. While there's nothing terribly > unreasonable about this on its face, it's only necessary so that > create_append_path() can call cost_sort(), which takes "root" but > doesn't actually use it. I'm not sure whether it's better to leave > this as-is or to remove the root argument from cost_sort().
Right offhand the cleanest answer to that seems to be to leave create_append_path alone, and make a separate function named something like create_ordered_append_path that handles the case where cost_sort might be needed. I rather wonder if we don't want two separate execution-time node types anyway, since what Append does seems significantly different from Merge (and MergeAppend would be just a misnomer). I have to run off for a doctors appointment, will continue looking at this patch when I get back. regards, tom lane -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers