===========MASTER:
 Hash Join  (cost=3085.45..23948.76 rows=1000000 width=12) (actual time=36.048..36.432 rows=4 loops=1)                          
   Hash Cond: (aa1.b = bb.b)                                                                                                    
   ->  Nested Loop  (cost=1.46..34.85 rows=1000000 width=8) (actual time=0.048..0.091 rows=4 loops=1)                           
         ->  Unique  (cost=1.03..1.04 rows=2 width=4) (actual time=0.015..0.018 rows=2 loops=1)                                 
               ->  Sort  (cost=1.03..1.03 rows=2 width=4) (actual time=0.015..0.016 rows=2 loops=1)                             
                     Sort Key: ai.a                                                                                             
                     Sort Method: quicksort  Memory: 25kB                                                                       
                     ->  Seq Scan on ai  (cost=0.00..1.02 rows=2 width=4) (actual time=0.008..0.009 rows=2 loops=1)             
         ->  Append  (cost=0.42..16.89 rows=2 width=8) (actual time=0.019..0.033 rows=2 loops=2)                                
               ->  Index Scan using aa1_pkey on aa1  (cost=0.42..8.44 rows=1 width=8) (actual time=0.018..0.020 rows=1 loops=2) 
                     Index Cond: (a = ai.a)                                                                                     
               ->  Index Scan using aa2_pkey on aa2  (cost=0.42..8.44 rows=1 width=8) (actual time=0.011..0.011 rows=1 loops=2) 
                     Index Cond: (a = ai.a)                                                                                     
   ->  Hash  (cost=1443.00..1443.00 rows=100000 width=8) (actual time=35.871..35.871 rows=100000 loops=1)                       
         Buckets: 131072  Batches: 2  Memory Usage: 2976kB                                                                      
         ->  Seq Scan on bb  (cost=0.00..1443.00 rows=100000 width=8) (actual time=0.008..15.230 rows=100000 loops=1)           
 Planning time: 0.334 ms                                                                                                        
 Execution time: 37.217 ms                                                                                                      

===========PATCHED:
 Nested Loop  (cost=1.75..36.10 rows=1 width=12) (actual time=0.021..0.040 rows=4 loops=1)                                      
   ->  Nested Loop  (cost=1.46..34.85 rows=4 width=8) (actual time=0.017..0.029 rows=4 loops=1)                                 
         ->  Unique  (cost=1.03..1.04 rows=2 width=4) (actual time=0.008..0.009 rows=2 loops=1)                                 
               ->  Sort  (cost=1.03..1.03 rows=2 width=4) (actual time=0.007..0.008 rows=2 loops=1)                             
                     Sort Key: ai.a                                                                                             
                     Sort Method: quicksort  Memory: 25kB                                                                       
                     ->  Seq Scan on ai  (cost=0.00..1.02 rows=2 width=4) (actual time=0.003..0.004 rows=2 loops=1)             
         ->  Append  (cost=0.42..16.89 rows=2 width=8) (actual time=0.005..0.009 rows=2 loops=2)                                
               ->  Index Scan using aa1_pkey on aa1  (cost=0.42..8.44 rows=1 width=8) (actual time=0.005..0.005 rows=1 loops=2) 
                     Index Cond: (a = ai.a)                                                                                     
               ->  Index Scan using aa2_pkey on aa2  (cost=0.42..8.44 rows=1 width=8) (actual time=0.003..0.003 rows=1 loops=2) 
                     Index Cond: (a = ai.a)                                                                                     
   ->  Index Scan using bb_pkey on bb  (cost=0.29..0.31 rows=1 width=8) (actual time=0.002..0.002 rows=1 loops=4)               
         Index Cond: (b = aa1.b)                                                                                                
 Planning time: 0.222 ms                                                                                                        
 Execution time: 0.076 ms