QUERY PLAN
Sort  (cost=41235.33..41386.96 rows=60652 width=65) (actual time=310.160..311.069 rows=25680 loops=1)
  Sort Key: sem.student_id, sem.semester
  Sort Method: quicksort  Memory: 3546kB
  ->  Hash Join  (cost=17188.20..36417.05 rows=60652 width=65) (actual time=120.278..277.411 rows=25680 loops=1)
        Hash Cond: (sem.student_id = s.student_id)
        ->  Nested Loop  (cost=16161.52..30416.22 rows=698820 width=69) (actual time=114.485..251.311 rows=199740 loops=1)
              ->  HashAggregate  (cost=16161.52..16183.00 rows=2148 width=4) (actual time=114.447..117.146 rows=9987 loops=1)
                    ->  Seq Scan on student_semester s2  (cost=0.00..16054.25 rows=42908 width=4) (actual time=0.015..107.698 rows=42331 loops=1)
                          Filter: ((college)::text = 'AS'::text)
              ->  Index Scan using student_id_index on student_semester sem  (cost=0.00..6.38 rows=20 width=65) (actual time=0.003..0.011 rows=20 loops=9987)
                    Index Cond: (student_id = s2.student_id)
        ->  Hash  (cost=988.73..988.73 rows=3036 width=4) (actual time=5.677..5.677 rows=3026 loops=1)
              Buckets: 1024  Batches: 1  Memory Usage: 107kB
              ->  Bitmap Heap Scan on student s  (cost=71.78..988.73 rows=3036 width=4) (actual time=0.926..4.008 rows=3026 loops=1)
                    Recheck Cond: (entryyear = 2006)
                    ->  Bitmap Index Scan on student_act_sat_entryyear_index  (cost=0.00..71.03 rows=3036 width=0) (actual time=0.856..0.856 rows=3026 loops=1)
                          Index Cond: (entryyear = 2006)
Total runtime: 312.338 ms