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 '%lawn%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3504465.77..3504470.49 rows=135 width=46) (actual time=399143.921..402756.269 rows=175 loops=1)
   Buffers: shared hit=30016593 read=911209 dirtied=2 written=2924
   ->  Sort  (cost=3504465.77..3504466.10 rows=135 width=46) (actual time=399129.737..400198.851 rows=3260082 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 556754kB
         Buffers: shared hit=30016593 read=911209 dirtied=2 written=2924
         ->  Nested Loop  (cost=2835528.57..3504460.99 rows=135 width=46) (actual time=165371.456..374748.548 rows=3260082 loops=1)
               Buffers: shared hit=30016585 read=911209 dirtied=2 written=2924
               ->  Nested Loop  (cost=2835528.57..3504422.49 rows=135 width=24) (actual time=165371.369..348353.355 rows=3260082 loops=1)
                     Buffers: shared hit=23496421 read=911209 dirtied=2 written=2924
                     ->  Nested Loop  (cost=2835528.57..3504155.04 rows=135 width=24) (actual time=165371.232..226429.779 rows=3260082 loops=1)
                           Buffers: shared hit=10659566 read=690122 written=2427
                           ->  Merge Join  (cost=2835528.57..3504115.73 rows=135 width=28) (actual time=165371.167..181824.061 rows=3260082 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=861735 read=690122 written=2427
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.015..8848.248 rows=7999993 loops=1)
                                       Buffers: shared hit=321252 read=112957 written=2422
                                 ->  Sort  (cost=2835528.42..2844027.09 rows=3399471 width=28) (actual time=165371.069..168158.070 rows=3260082 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 352998kB
                                       Buffers: shared hit=540483 read=577165 written=5
                                       ->  Hash Join  (cost=66923.39..2466738.87 rows=3399471 width=28) (actual time=3692.973..158892.781 rows=3260082 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=540480 read=577165 written=5
                                             ->  Seq Scan on lineitem  (cost=0.00..1683567.42 rows=60644742 width=24) (actual time=0.029..43140.448 rows=60044872 loops=1)
                                                   Buffers: shared hit=536245 read=540875 written=5
                                             ->  Hash  (cost=65522.00..65522.00 rows=112111 width=4) (actual time=3692.549..3692.549 rows=108565 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3817kB
                                                   Buffers: shared hit=4232 read=36290
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=112111 width=4) (actual time=0.028..3600.952 rows=108565 loops=1)
                                                         Filter: ((p_name)::text ~~ '%lawn%'::text)
                                                         Rows Removed by Filter: 1891435
                                                         Buffers: shared hit=4232 read=36290
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.012..0.012 rows=1 loops=3260082)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9797831
                     ->  Index Only Scan using orders_o_orderkey_o_orderdate_idx on orders  (cost=0.00..1.97 rows=1 width=8) (actual time=0.036..0.036 rows=1 loops=3260082)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Heap Fetches: 3260082
                           Buffers: shared hit=12836855 read=221087 dirtied=2 written=497
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.005..0.006 rows=1 loops=3260082)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6520164
 Total runtime: 402869.578 ms
(44 rows)

COMMIT;
COMMIT