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 '%medium%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3514462.13..3514467.17 rows=144 width=46) (actual time=267221.894..270812.846 rows=175 loops=1)
   Buffers: shared hit=30408529 read=606031 dirtied=658 written=1880
   ->  Sort  (cost=3514462.13..3514462.49 rows=144 width=46) (actual time=267203.352..268346.108 rows=3270538 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 558224kB
         Buffers: shared hit=30408529 read=606031 dirtied=658 written=1880
         ->  Nested Loop  (cost=2843898.38..3514456.97 rows=144 width=46) (actual time=126076.616..246355.212 rows=3270538 loops=1)
               Buffers: shared hit=30408521 read=606031 dirtied=658 written=1880
               ->  Nested Loop  (cost=2843898.38..3514415.90 rows=144 width=24) (actual time=126076.521..227607.204 rows=3270538 loops=1)
                     Buffers: shared hit=23867445 read=606031 dirtied=658 written=1880
                     ->  Nested Loop  (cost=2843898.38..3514134.41 rows=144 width=24) (actual time=126076.478..161813.989 rows=3270538 loops=1)
                           Buffers: shared hit=10888646 read=484873 dirtied=654 written=827
                           ->  Merge Join  (cost=2843898.38..3514092.48 rows=144 width=28) (actual time=126076.429..139026.337 rows=3270538 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=1058472 read=484873 dirtied=654 written=827
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.33 rows=8000000 width=12) (actual time=0.015..6067.794 rows=7999993 loops=1)
                                       Buffers: shared hit=329424 read=104785 written=230
                                 ->  Sort  (cost=2843898.36..2852932.16 rows=3613517 width=28) (actual time=126076.249..128598.934 rows=3270538 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 353815kB
                                       Buffers: shared hit=729048 read=380088 dirtied=654 written=597
                                       ->  Hash Join  (cost=67023.48..2450296.52 rows=3613517 width=28) (actual time=1931.769..122065.484 rows=3270538 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=729045 read=380088 dirtied=654 written=597
                                             ->  Seq Scan on lineitem  (cost=0.00..1670269.12 rows=60166112 width=24) (actual time=0.035..23426.252 rows=60045379 loops=1)
                                                   Buffers: shared hit=727258 read=341350 dirtied=654 written=597
                                             ->  Hash  (cost=65522.00..65522.00 rows=120118 width=4) (actual time=1931.372..1931.372 rows=108950 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3831kB
                                                   Buffers: shared hit=1784 read=38738
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=120118 width=4) (actual time=0.027..1842.513 rows=108950 loops=1)
                                                         Filter: ((p_name)::text ~~ '%medium%'::text)
                                                         Rows Removed by Filter: 1891050
                                                         Buffers: shared hit=1784 read=38738
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.005..0.006 rows=1 loops=3270538)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9830174
                     ->  Index Scan using pk_orders on orders  (cost=0.00..1.94 rows=1 width=8) (actual time=0.019..0.019 rows=1 loops=3270538)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Buffers: shared hit=12978799 read=121158 dirtied=4 written=1053
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.003..0.004 rows=1 loops=3270538)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6541076
 Total runtime: 270922.966 ms
(43 rows)

COMMIT;
COMMIT