On Monday 16 October 2006 16:37, Carlo Stonebanks wrote: > The facility_address_id is null statement is necessary, as this is a > sub-query from a union clause and I want to optimise the query with > the original logic intact. The value is not hard coded to true but > rather to null. Heh, you neglect to mention that this query is discovering faculty who do *not* have an address entry, which makes the "is null" a major necessity. With that, how did a "not exists (blabla faculty_address blabla)" subquery to get the same effect treat you? How about an "IN (blabla LIMIT 1)" ? -- Shaun Thomas Database Administrator Leapfrog Online 807 Greenwood Street Evanston, IL 60201 Tel. 847-440-8253 Fax. 847-570-5750 www.leapfrogonline.com