Tom Lane wrote:
> 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
>
>
Thanks for the response Tom, I am a SQL neophyte, so I'll try to rework the query. The explain analyze
runs forever, or longer than a day anyway.
Regards,
Steve