2011/5/25 Hitoshi Harada <umi.tan...@gmail.com>: > So I'm still > thinking which of pulling up and parameterized scan is better.
After more investigation I came up with third idea, pushing down RangeTblEntry to aggregate subquery. This sounds like a crazy idea, but it seems to me like it is slightly easier than pulling up agg-subquery. The main point is that when you want to pull up, you must care if the final output would be correct with other join relations than the aggregate-related one. In contrast, when pushing down the target relation to agg-subquery it is simple to ensure the result. I'm looking around pull_up_subqueries() in subquery_planner() to add the pushing down logic. It could be possible to do it around make_one_rel() but I bet query structure changes are doable against Query, not PlannerInfo. I appreciate any comments. Regards, -- Hitoshi Harada -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
