Re: Slow left outer join

Alexander Staubo <alex@purefiction.net> writes:
> select comments.*, users.*
> from comments
> left outer join users on
>    users.id = comments.creator_id
> inner join events_comments on
>    comments.id = events_comments.comment_id
>    and events_comments.event_id = 9244

> The outer join seems unnecessarily slow.

Try flipping the order of the two joins.  PG 8.2 will be smart enough to
do that for itself, but no existing release understands when it's safe
to rearrange outer-join order.

            regards, tom lane