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 '%white%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3377518.10..3377522.55 rows=127 width=46) (actual time=175071.466..178063.985 rows=175 loops=1)
   Buffers: shared hit=30702567 read=299131 written=1570
   ->  Sort  (cost=3377518.10..3377518.42 rows=127 width=46) (actual time=175059.570..175922.468 rows=3269103 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 558022kB
         Buffers: shared hit=30702567 read=299131 written=1570
         ->  Nested Loop  (cost=2710590.73..3377513.66 rows=127 width=46) (actual time=87272.008..156226.878 rows=3269103 loops=1)
               Buffers: shared hit=30702559 read=299131 written=1570
               ->  Nested Loop  (cost=2710590.73..3377477.44 rows=127 width=24) (actual time=87271.923..146444.755 rows=3269103 loops=1)
                     Buffers: shared hit=24164353 read=299131 written=1570
                     ->  Nested Loop  (cost=2710590.73..3377228.77 rows=127 width=24) (actual time=87271.835..107473.866 rows=3269103 loops=1)
                           Buffers: shared hit=11086787 read=282498 written=3
                           ->  Merge Join  (cost=2710590.73..3377191.79 rows=127 width=28) (actual time=87271.784..95871.685 rows=3269103 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=1261905 read=282497 written=3
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.025..3564.913 rows=7999933 loops=1)
                                       Buffers: shared hit=434203 read=5
                                 ->  Sort  (cost=2710588.56..2718425.48 rows=3134770 width=28) (actual time=87271.625..89332.250 rows=3269103 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 353703kB
                                       Buffers: shared hit=827702 read=282492 written=3
                                       ->  Hash Join  (cost=66823.26..2372348.00 rows=3134770 width=28) (actual time=1274.481..83232.072 rows=3269103 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=827699 read=282492 written=3
                                             ->  Seq Scan on lineitem  (cost=0.00..1671921.52 rows=60225552 width=24) (actual time=0.026..15135.589 rows=59985781 loops=1)
                                                   Buffers: shared hit=821847 read=247819 written=3
                                             ->  Hash  (cost=65522.00..65522.00 rows=104101 width=4) (actual time=1274.284..1274.284 rows=109063 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3835kB
                                                   Buffers: shared hit=5849 read=34673
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=104101 width=4) (actual time=0.033..1218.398 rows=109063 loops=1)
                                                         Filter: ((p_name)::text ~~ '%white%'::text)
                                                         Rows Removed by Filter: 1890937
                                                         Buffers: shared hit=5849 read=34673
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.003..0.003 rows=1 loops=3269103)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9824882 read=1
                     ->  Index Scan using pk_orders on orders  (cost=0.00..1.95 rows=1 width=8) (actual time=0.011..0.011 rows=1 loops=3269103)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Buffers: shared hit=13077566 read=16633 written=1567
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.002..0.002 rows=1 loops=3269103)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6538206
 Total runtime: 178172.392 ms
(43 rows)

COMMIT;
COMMIT