uni=# explain analyze
uni=# select s1.code, s2.code
uni-# from Subjects s1, Subjects s2
uni-# where s1.offeredBy = s2.offeredBy;
                        QUERY PLAN
---------------------------------------------------------------
Hash Join  (cost=1286.03..108351.87 rows=7113299 width=18)
           (actual time=8.966..903.441 rows=7328594 loops=1)
  Hash Cond: (s1.offeredby = s2.offeredby)
  ->  Seq Scan on subjects s1
          (cost=0.00..1063.79 rows=17779 width=13)
          (actual time=0.013..2.861 rows=17779 loops=1)
  ->  Hash  (cost=1063.79..1063.79 rows=17779 width=13)
            (actual time=8.667..8.667 rows=17720 loops=1)
        Buckets: 32768  Batches: 1  Memory Usage: 1087kB
        ->  Seq Scan on subjects s2
                (cost=0.00..1063.79 rows=17779 width=13)
                (actual time=0.009..4.677 rows=17779 loops=1)
Planning time: 0.255 ms
Execution time: 1191.023 ms