Read the docs on "exists" that should be what you are looking for.
--rob
----- Original Message -----
From: "Diehl, Jeffrey" <jdiehl@sandia.gov>
To: <pgsql-sql@postgresql.org>; <pgsql-general@postgresql.org>
Cc: "Diehl, Jeffrey" <jdiehl@sandia.gov>
Sent: Tuesday, January 16, 2001 3:42 PM
Subject: Help with query. (*)
> I'm having difficulty writing a query which I really can't live without...
>
> I need to get a list of records from table A for which there are
> corresponding records in table B. I've tried to use the intersect clause,
> but it doesn't seem to work, or it runs far too long. For example:
>
> select * from A
> where 1=1
> intersect select * from A where
> B.x=A.x
> and A.y=B.y
> and A.z=B.z
> limit 100
>
> I need the most efficient method possible; my A tables have upward of 5
> Million records. The B table, btw, only has about 100 records.
>
>
> Any help will be most appreciated.
>
>
