Re: Unusual slowdown using subselects

> calendar=# explain select * from schedule where schedule.owner_id in
> (select group_id from groups where user_id=101);

> calendar=# explain select * from schedule where schedule.owner_id=101 or
> schedule.owner_id=102;

A sub-select is different than a join, and is tretaed differently by the
database, and they are much, much slower than simply doing a join. So, we
use subselects only when absolutely, positively necessary, otherwise, we
just do a join.

steve