BEGIN;
BEGIN
EXPLAIN (ANALYZE, BUFFERS)
select
	nation,
	o_year,
	sum(amount) as sum_profit
from
	(
		select
			n_name as nation,
			extract(year from o_orderdate) as o_year,
			l_extendedprice * (1 - l_discount) - ps_supplycost * l_quantity as amount
		from
			part,
			supplier,
			lineitem,
			partsupp,
			orders,
			nation
		where
			s_suppkey = l_suppkey
			and ps_suppkey = l_suppkey
			and ps_partkey = l_partkey
			and p_partkey = l_partkey
			and o_orderkey = l_orderkey
			and s_nationkey = n_nationkey
			and p_name like '%red%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3361413.38..3361417.51 rows=118 width=46) (actual time=236562.024..240103.313 rows=175 loops=1)
   Buffers: shared hit=30668742 read=393509 written=2734
   ->  Sort  (cost=3361413.38..3361413.67 rows=118 width=46) (actual time=236547.874..237599.505 rows=3275442 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 558914kB
         Buffers: shared hit=30668742 read=393509 written=2734
         ->  Nested Loop  (cost=2695796.96..3361409.32 rows=118 width=46) (actual time=109296.019..216025.609 rows=3275442 loops=1)
               Buffers: shared hit=30668734 read=393509 written=2734
               ->  Nested Loop  (cost=2695796.96..3361375.66 rows=118 width=24) (actual time=109295.934..198255.318 rows=3275442 loops=1)
                     Buffers: shared hit=24117850 read=393509 written=2734
                     ->  Nested Loop  (cost=2695796.96..3361143.45 rows=118 width=24) (actual time=109295.803..141940.211 rows=3275442 loops=1)
                           Buffers: shared hit=10998839 read=393064 written=2729
                           ->  Merge Join  (cost=2695796.96..3361108.80 rows=119 width=28) (actual time=109295.750..122103.423 rows=3275442 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=1154529 read=393064 written=2729
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.33 rows=8000000 width=12) (actual time=0.019..6004.116 rows=7999993 loops=1)
                                       Buffers: shared hit=309389 read=124820 written=2728
                                 ->  Sort  (cost=2695796.85..2703203.68 rows=2962730 width=28) (actual time=109295.506..111817.593 rows=3275442 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 354198kB
                                       Buffers: shared hit=845140 read=268244 written=1
                                       ->  Hash Join  (cost=66748.20..2377325.66 rows=2962730 width=28) (actual time=1832.142..105050.341 rows=3275442 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=845137 read=268244 written=1
                                             ->  Seq Scan on lineitem  (cost=0.00..1676903.08 rows=60404708 width=24) (actual time=0.043..20051.884 rows=60045310 loops=1)
                                                   Buffers: shared hit=838034 read=234822 written=1
                                             ->  Hash  (cost=65522.00..65522.00 rows=98096 width=4) (actual time=1831.775..1831.775 rows=109094 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3836kB
                                                   Buffers: shared hit=7100 read=33422
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=98096 width=4) (actual time=0.039..1745.405 rows=109094 loops=1)
                                                         Filter: ((p_name)::text ~~ '%red%'::text)
                                                         Rows Removed by Filter: 1890906
                                                         Buffers: shared hit=7100 read=33422
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.005..0.005 rows=1 loops=3275442)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9844310
                     ->  Index Only Scan using orders_o_orderkey_o_orderdate_idx on orders  (cost=0.00..1.96 rows=1 width=8) (actual time=0.016..0.016 rows=1 loops=3275442)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Heap Fetches: 3275442
                           Buffers: shared hit=13119011 read=445 written=5
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.003..0.003 rows=1 loops=3275442)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6550884
 Total runtime: 240221.353 ms
(44 rows)

COMMIT;
COMMIT