On 5 December 2012 23:37, David Rowley <dgrowle...@gmail.com> wrote: > Though this plan might not be quite as optimal as it could be as it performs > the grouping after the join.
PostgreSQL always calculates aggregation as the last step. It's a well known optimisation to push-down GROUP BY clauses to the lowest level, but we don't do that, yet. You're right that it can make a massive difference to many queries. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
