Hi Robert, could you try with "exists" ? SELECT c.* FROM contacts c WHERE exists ( SELECT 1 FROM phone p WHERE p.addr =? and p.contact_id= c.id ) OR exists (SELECT 1 FROM email e WHERE e.addr = ? and e.contact_id=c.id );
2013/11/21 Robert DiFalco <robert.difa...@gmail.com> > I have found this: > > SELECT c.* > FROM contacts c > WHERE c.id IN ( SELECT p.contact_id FROM phone p WHERE p.addr = ? ) > OR c.id IN (SELECT e.contact_id FROM email e WHERE e.addr = ? ); > > To have a worse plan than: > > SELECT * FROM contacts where id IN ( > ( SELECT c.id FROM contacts c > JOIN phone p ON c.id = p.contact_id AND p.addr = ? > UNION > SELECT c.id FROM contacts c > JOIN email e ON c.id = e.contact_id AND e.addr = ? ); > > Maybe this is no surprise. But after discovering this my question is this, > is there another option I dont' know about that is logically the same that > can perform even better than the UNION? >
