uni=# explain analyze
uni-# select s.id,p.name
uni-# from Students s, People p where s.id=p.id;
                      QUERY PLAN
----------------------------------------------------------
Merge Join  (cost=0.58..2829.25 rows=31361 width=18)
            (actual time=0.044..25.883 rows=31361 loops=1)
  Merge Cond: (s.id = p.id)
  ->  Index Only Scan using students_pkey on students s
            (cost=0.29..995.70 rows=31361 width=4)
            (actual time=0.033..6.195 rows=31361 loops=1)
        Heap Fetches: 31361
  ->  Index Scan using people_pkey on people p
            (cost=0.29..2434.49 rows=55767 width=18)
            (actual time=0.006..6.662 rows=31361 loops=1)
Planning time: 0.259 ms
Execution time: 27.327 ms