On Sat, Jul 3, 2010 at 8:47 PM, Maksym Boguk <maxim.bo...@gmail.com> wrote: > notable planner had correctly estimated amount of rows in one side of the > join: > (Append (cost=0.00..0.98 rows=2 width=4)) > and planner hard correctly estimated amount of rows in the another side of > the join: > Index Scan using t3_value_key on t3 (cost=0.00..0.49 rows=1 width=8) > > And instead of use 2(from append)*1(from scan on t3)=2 as final row > estimation, planner chooses use heuristic value 1000.
2 isn't necessarily correct, because the two rows on the outer side needn't match the 1 row on the inner side - it could be less. But I agree with you that the estimate of 1000 doesn't seem to make much sense. I'm not sure where that's coming from. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise Postgres Company -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs
