reset enable_hashjoin=false;
set enable_mergejoin=false;
set random_page_cost=20;

HashAggregate  (cost=126233158.01..126233163.21 rows=347 width=53) (actual time=82471.963..82471.983 rows=26 loops=1)
  ->  Nested Loop  (cost=0.00..125974847.48 rows=248974 width=53) (actual time=473.558..39846.799 rows=414249 loops=1)
        Join Filter: (a.product_operation = o.id)
        Rows Removed by Join Filter: 16569960
        ->  Nested Loop Left Join  (cost=0.00..125821726.96 rows=248974 width=42) (actual time=473.500..35090.816 rows=414249 loops=1)
              ->  Index Scan using trans_posted_1_trans_date_idx on table_a_1 a  (cost=0.00..371973.35 rows=248974 width=36) (actual time=81.080..27242.825 rows=414249 loops=1)
                    Index Cond: ((transaction_date >= '2013-01-01 00:00:00+00'::timestamp with time zone) AND (transaction_date < '2013-02-01 00:00:00+00'::timestamp with time zone))
                    Filter: ((twin_id IS NULL) AND (product_id = 1) AND ((trans_type_id = ANY ('{2,3,4}'::integer[])) OR (trans_type_id IS NULL)))
                    Rows Removed by Filter: 546641
              ->  Index Scan using table_b_1_ptid_orgid_ym_unq on table_b_1 b  (cost=0.00..503.86 rows=1 width=10) (actual time=0.016..0.017 rows=1 loops=414249)
                    Index Cond: ((a.id = a_id) AND (organization_id = 2) AND (year = 2013) AND (month = 3))
                    Filter: (product_id = 1)
        ->  Materialize  (cost=0.00..1.62 rows=41 width=19) (actual time=0.000..0.004 rows=41 loops=414249)
              ->  Seq Scan on product_operations o  (cost=0.00..1.41 rows=41 width=19) (actual time=0.026..0.036 rows=41 loops=1)
Total runtime: 82472.294 ms
(15 rows)

set enable_hashjoin=true;
set enable_mergejoin=true;
set random_page_cost=20;

HashAggregate  (cost=19998189.54..19998194.75 rows=347 width=53) (actual time=825795.403..825795.420 rows=26 loops=1)
  ->  Nested Loop  (cost=375085.52..19739879.02 rows=248974 width=53) (actual time=727075.300..782232.417 rows=414249 loops=1)
        Join Filter: (a.product_operation = o.id)
        Rows Removed by Join Filter: 16569960
        ->  Hash Right Join  (cost=375085.52..19586758.50 rows=248974 width=42) (actual time=727075.034..777530.559 rows=414249 loops=1)
              Hash Cond: (b.a_id = a.id)
              ->  Seq Scan on table_b_1 b  (cost=0.00..19153996.20 rows=4605486 width=10) (actual time=193813.645..733574.903 rows=6416840 loops=1)
                    Filter: ((product_id = 1) AND (organization_id = 2) AND (year = 2013) AND (month = 3))
                    Rows Removed by Filter: 596869132
              ->  Hash  (cost=371973.35..371973.35 rows=248974 width=36) (actual time=23994.832..23994.832 rows=414249 loops=1)
                    Buckets: 32768  Batches: 1  Memory Usage: 27509kB
                    ->  Index Scan using table_a_1_trans_date_idx on table_a_1 a  (cost=0.00..371973.35 rows=248974 width=36) (actual time=1.051..23615.761 rows=414249 loops=1)
                          Index Cond: ((transaction_date >= '2013-01-01 00:00:00+00'::timestamp with time zone) AND (transaction_date < '2013-02-01 00:00:00+00'::timestamp with time zone))
                          Filter: ((twin_id IS NULL) AND (product_id = 1) AND ((trans_type_id = ANY ('{2,3,4}'::integer[])) OR (trans_type_id IS NULL)))
                          Rows Removed by Filter: 546641
        ->  Materialize  (cost=0.00..1.62 rows=41 width=19) (actual time=0.000..0.004 rows=41 loops=414249)
              ->  Seq Scan on product_operations o  (cost=0.00..1.41 rows=41 width=19) (actual time=0.175..0.189 rows=41 loops=1)
Total runtime: 825802.496 ms