Thread: Select Statement Hang...

I was trying to set up a foreign key for an id field but found out that some
of the ids are not in the referenced table.  To look things up, I tried

select id from btable where id not in (select id from atable)

The query just hang.....  My tables are pretty big (200, 000?)  can anyone
help me to pinpoint the problem?

Thanks!

> I was trying to set up a foreign key for an id field but found out that
some
> of the ids are not in the referenced table.  To look things up, I tried
>
> select id from btable where id not in (select id from atable)
>
> The query just hang.....  My tables are pretty big (200, 000?)  can anyone
> help me to pinpoint the problem?
>
> Thanks!
>

You might try

select id
from btable
where not exists
(select id from atable)

I have found that this performs better.
You should also make sure that you've vacuumed your tables.

If this doesnt help, post the results of

explain analyze
select id
from btable
where not exists
(select id from atable)

HTH
Chad