tpro=# select count(*) from log.students_processed_by_apperson log where exists ( select * from scores.answers_given ag where log.student_id = ag.student_id and log.admin_id = ag.admin_id and ag.admin_id > 8 ) and log.batch = '2009-11-20' a
nd last_modified > '2009-11-25 18:00:00' and log.answers_recorded > 0;
 count
-------
   128
(1 row)

tpro=#