So in the grouping sets patch post, I said: >> There is one current weakness which I don't see a good solution for: >> the planner code still has to pick a single value for group_pathkeys >> before planning the input path. This means that we sometimes can't >> choose a minimal set of sorts, because we may have chosen a sort >> order for a grouping set that should have been hashed,
Of course there is one good solution, which is to have query_planner take a set of acceptable output sort orders rather than just a single one. How wild an idea is this? I guess a possible hazard is an increase in the number of possible mergejoin paths to consider. What other possible issues are there? -- Andrew (irc:RhodiumToad) -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
