What are the ids for courses in the Fall of 2009 or the Spring of 2010?
SELECT course_id FROM SECTION WHERE semester  =  'Fall' AND YEAR  =  2009 UNION SELECT course_id FROM SECTION WHERE semester  =  'Spring' AND YEAR  =  2010
ids for courses refers to course_id; in the Fall of 2009 refers to semester = 'Fall' AND year = 2009; or the Spring of 2010 refers to semester = 'Spring' AND year = 2010; UNION is used to combine the results of two SELECT queries.