QUERY PLAN                                    
----------------------------------------------------------------------------------
 Merge Join  (cost=6385.49..6829.49 rows=2880000 width=8)
   Merge Cond: (tab3.k = b.j)
   ->  Sort  (cost=6216.75..6222.75 rows=2400 width=8)
         Sort Key: tab3.k
         ->  Nested Loop  (cost=40.00..6082.00 rows=2400 width=8)
               ->  HashAggregate  (cost=40.00..42.00 rows=200 width=4)
                     ->  Seq Scan on tab3  (cost=0.00..34.00 rows=2400 width=4)
               ->  Materialize  (cost=0.00..46.00 rows=2400 width=4)
                     ->  Seq Scan on tab1 a  (cost=0.00..34.00 rows=2400 width=4)
   ->  Sort  (cost=168.75..174.75 rows=2400 width=4)
         Sort Key: b.j
         ->  Seq Scan on tab2 b  (cost=0.00..34.00 rows=2400 width=4)
(12 rows)

                                    QUERY PLAN                                    
----------------------------------------------------------------------------------
 Merge Join  (cost=6385.49..6829.49 rows=2880000 width=8)
   Merge Cond: (tab3.k = a.i)
   ->  Sort  (cost=6216.75..6222.75 rows=2400 width=8)
         Sort Key: tab3.k
         ->  Nested Loop  (cost=40.00..6082.00 rows=2400 width=8)
               ->  HashAggregate  (cost=40.00..42.00 rows=200 width=4)
                     ->  Seq Scan on tab3  (cost=0.00..34.00 rows=2400 width=4)
               ->  Materialize  (cost=0.00..46.00 rows=2400 width=4)
                     ->  Seq Scan on tab2 b  (cost=0.00..34.00 rows=2400 width=4)
   ->  Sort  (cost=168.75..174.75 rows=2400 width=4)
         Sort Key: a.i
         ->  Seq Scan on tab1 a  (cost=0.00..34.00 rows=2400 width=4)
(12 rows)

                                      QUERY PLAN                                      
--------------------------------------------------------------------------------------
 Nested Loop Left Join  (cost=44.50..36148.50 rows=2880000 width=8)
   ->  Seq Scan on tab1 a  (cost=0.00..34.00 rows=2400 width=4)
   ->  Materialize  (cost=44.50..117.50 rows=1200 width=4)
         ->  Hash Join  (cost=44.50..111.50 rows=1200 width=4)
               Hash Cond: (b.j = tab3.k)
               ->  Seq Scan on tab2 b  (cost=0.00..34.00 rows=2400 width=4)
               ->  Hash  (cost=42.00..42.00 rows=200 width=4)
                     ->  HashAggregate  (cost=40.00..42.00 rows=200 width=4)
                           ->  Seq Scan on tab3  (cost=0.00..34.00 rows=2400 width=4)
(9 rows)

                              QUERY PLAN                               
-----------------------------------------------------------------------
 Nested Loop Left Join  (cost=0.00..115372874.00 rows=2880000 width=8)
   Join Filter: (SubPlan 1)
   ->  Seq Scan on tab1 a  (cost=0.00..34.00 rows=2400 width=4)
   ->  Materialize  (cost=0.00..46.00 rows=2400 width=4)
         ->  Seq Scan on tab2 b  (cost=0.00..34.00 rows=2400 width=4)
   SubPlan 1
     ->  Seq Scan on tab3  (cost=0.00..40.00 rows=12 width=4)
           Filter: (k = a.i)
(8 rows)

                              QUERY PLAN                               
-----------------------------------------------------------------------
 Nested Loop Left Join  (cost=0.00..115372874.00 rows=2880000 width=8)
   Join Filter: (SubPlan 1)
   ->  Seq Scan on tab1 a  (cost=0.00..34.00 rows=2400 width=4)
   ->  Materialize  (cost=0.00..46.00 rows=2400 width=4)
         ->  Seq Scan on tab2 b  (cost=0.00..34.00 rows=2400 width=4)
   SubPlan 1
     ->  Seq Scan on tab3  (cost=0.00..40.00 rows=12 width=4)
           Filter: (k = b.j)
(8 rows)