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 '%ghost%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3675964.06..3675969.73 rows=162 width=46) (actual time=269625.147..272784.502 rows=175 loops=1)
   Buffers: shared hit=30170265 read=871870 dirtied=161 written=5316
   ->  Sort  (cost=3675964.06..3675964.46 rows=162 width=46) (actual time=269612.112..270571.901 rows=3272559 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 558508kB
         Buffers: shared hit=30170265 read=871870 dirtied=161 written=5316
         ->  Nested Loop  (cost=3001884.77..3675958.11 rows=162 width=46) (actual time=120129.077..247511.739 rows=3272559 loops=1)
               Buffers: shared hit=30170257 read=871870 dirtied=161 written=5316
               ->  Nested Loop  (cost=3001884.77..3675911.91 rows=162 width=24) (actual time=120128.990..228574.731 rows=3272559 loops=1)
                     Buffers: shared hit=23625139 read=871870 dirtied=161 written=5316
                     ->  Nested Loop  (cost=3001884.77..3675589.90 rows=162 width=24) (actual time=120128.941..157345.896 rows=3272559 loops=1)
                           Buffers: shared hit=10729178 read=659753 written=2934
                           ->  Merge Join  (cost=3001884.77..3675542.44 rows=163 width=28) (actual time=120128.866..133714.102 rows=3272559 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=894830 read=659169 written=2934
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.33 rows=8000000 width=12) (actual time=0.062..6818.124 rows=7999973 loops=1)
                                       Buffers: shared hit=269594 read=164615 written=2915
                                 ->  Sort  (cost=3001884.76..3012073.01 rows=4075300 width=28) (actual time=120128.707..122537.910 rows=3272559 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 353973kB
                                       Buffers: shared hit=625236 read=494554 written=19
                                       ->  Hash Join  (cost=67198.64..2554447.90 rows=4075300 width=28) (actual time=1826.891..116628.043 rows=3272559 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=625233 read=494554 written=19
                                             ->  Seq Scan on lineitem  (cost=0.00..1686921.67 rows=60765967 width=24) (actual time=0.064..22425.872 rows=60045297 loops=1)
                                                   Buffers: shared hit=618054 read=461208 written=7
                                             ->  Hash  (cost=65522.00..65522.00 rows=134131 width=4) (actual time=1826.468..1826.468 rows=108973 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3832kB
                                                   Buffers: shared hit=7176 read=33346 written=12
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=134131 width=4) (actual time=0.035..1738.310 rows=108973 loops=1)
                                                         Filter: ((p_name)::text ~~ '%ghost%'::text)
                                                         Rows Removed by Filter: 1891027
                                                         Buffers: shared hit=7176 read=33346 written=12
                           ->  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=3272559)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9834348 read=584
                     ->  Index Scan using pk_orders on orders  (cost=0.00..1.98 rows=1 width=8) (actual time=0.020..0.021 rows=1 loops=3272559)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Buffers: shared hit=12895961 read=212117 dirtied=161 written=2382
               ->  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=3272559)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6545118
 Total runtime: 272891.730 ms
(43 rows)

COMMIT;
COMMIT