Robert Haas <robertmh...@gmail.com> writes: > Not sure what you mean. There's already a special-case code path for > cross joins; but I think it's probably considering a lot of silly > paths. Is there a case where it makes sense to do cross joins at some > stage of the process other than last?
They *are* done last, as a rule, because of the heuristic that prefers to join where there's a join clause. (However I've gotten negative comments about that --- some people think that when joining small detail tables to a big fact table, it'd be better to cross-join the detail tables and then do one multi-clause join to the big table. I'm unconvinced myself but there does seem to be more than one school of thought about it.) 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