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 '%midnight%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3390861.86..3390866.27 rows=126 width=46) (actual time=276539.271..280121.856 rows=175 loops=1)
   Buffers: shared hit=30148639 read=928090 dirtied=147 written=20845
   ->  Sort  (cost=3390861.86..3390862.17 rows=126 width=46) (actual time=276525.580..277578.208 rows=3276721 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 559093kB
         Buffers: shared hit=30148639 read=928090 dirtied=147 written=20845
         ->  Nested Loop  (cost=2723817.08..3390857.46 rows=126 width=46) (actual time=124343.853..255247.565 rows=3276721 loops=1)
               Buffers: shared hit=30148631 read=928090 dirtied=147 written=20845
               ->  Nested Loop  (cost=2723817.08..3390821.53 rows=126 width=24) (actual time=124343.785..234208.114 rows=3276721 loops=1)
                     Buffers: shared hit=23595189 read=928090 dirtied=147 written=20845
                     ->  Nested Loop  (cost=2723817.08..3390572.74 rows=126 width=24) (actual time=124343.609..161362.665 rows=3276721 loops=1)
                           Buffers: shared hit=10858233 read=540177 written=9863
                           ->  Merge Join  (cost=2723817.08..3390536.05 rows=126 width=28) (actual time=124343.573..138025.421 rows=3276721 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=1009535 read=540177 written=9863
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.33 rows=8000000 width=12) (actual time=0.009..6467.972 rows=7999949 loops=1)
                                       Buffers: shared hit=332470 read=101738 written=9859
                                 ->  Sort  (cost=2723816.97..2731692.82 rows=3150338 width=28) (actual time=124343.469..127002.178 rows=3276721 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 354298kB
                                       Buffers: shared hit=677065 read=438439 written=4
                                       ->  Hash Join  (cost=66823.27..2383784.06 rows=3150338 width=28) (actual time=1535.458..120701.930 rows=3276721 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=677062 read=438439 written=4
                                             ->  Seq Scan on lineitem  (cost=0.00..1680216.70 rows=60524070 width=24) (actual time=0.027..22296.753 rows=60044082 loops=1)
                                                   Buffers: shared hit=677057 read=397919 written=4
                                             ->  Hash  (cost=65522.00..65522.00 rows=104102 width=4) (actual time=1535.256..1535.256 rows=109013 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3833kB
                                                   Buffers: shared hit=2 read=40520
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=104102 width=4) (actual time=0.022..1463.785 rows=109013 loops=1)
                                                         Filter: ((p_name)::text ~~ '%midnight%'::text)
                                                         Rows Removed by Filter: 1890987
                                                         Buffers: shared hit=2 read=40520
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.006..0.006 rows=1 loops=3276721)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9848698
                     ->  Index Only Scan using orders_o_orderkey_o_orderdate_idx on orders  (cost=0.00..1.96 rows=1 width=8) (actual time=0.021..0.021 rows=1 loops=3276721)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Heap Fetches: 3276721
                           Buffers: shared hit=12736956 read=387913 dirtied=147 written=10982
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.004..0.004 rows=1 loops=3276721)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6553442
 Total runtime: 280228.923 ms
(44 rows)

COMMIT;
COMMIT