Re: 8.3.1 query plan

Steve Clark <sclark@netwolves.com> writes:
> explain insert into myevents select * from t_unit_event_log a where exists
>         (select b.event_log_no from myevents b
>          where a.event_status = 1 and a.event_ref_log_no IS NOT NULL
>                 and a.event_ref_log_no = b.event_log_no and a.event_log_no not in
>                         (select event_log_no from myevents)
>         )

Consider testing the conditions on A at the top level, instead of
redundantly checking them inside the sub-query on B.  I'm not certain
exactly how much that's hurting you (EXPLAIN ANALYZE output would've
been more informative), but it can't be good.

            regards, tom lane