Hi all

I have a piece of SQL that really needs to be performed quicker, I have 2 tables:

Person
Referral

Person has a date of birth and I am fetching all persons who were under 18 on their first referral, here is the SQL:

select *;
  from person p
 inner join referral r on p.cl_ref = r.cl_ref and !empty(r.re_date);
      where gomonth(p.cl_dob, 216) > (select min(rr.re_date) from referral rr;
                                             where rr.cl_ref = p.cl_ref and !empty(rr.re_date))

According to Fox none of this is optimised, both cl_ref fields on each table are indexed.

Can anyone suggest an alternative that may be quicker - or is there anything else I could do to speed up the query?

Thanks
Kev