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 '%dark%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3340203.22..3340207.25 rows=115 width=46) (actual time=269805.237..273272.862 rows=175 loops=1)
   Buffers: shared hit=30152286 read=701295 dirtied=133 written=1626
   ->  Sort  (cost=3340203.22..3340203.51 rows=115 width=46) (actual time=269792.026..270828.844 rows=3252754 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 555723kB
         Buffers: shared hit=30152286 read=701295 dirtied=133 written=1626
         ->  Nested Loop  (cost=2675157.69..3340199.28 rows=115 width=46) (actual time=125328.580..249440.482 rows=3252754 loops=1)
               Buffers: shared hit=30152278 read=701295 dirtied=133 written=1626
               ->  Nested Loop  (cost=2675157.69..3340166.49 rows=115 width=24) (actual time=125328.497..229472.561 rows=3252754 loops=1)
                     Buffers: shared hit=23646770 read=701295 dirtied=133 written=1626
                     ->  Nested Loop  (cost=2675157.69..3339942.07 rows=115 width=24) (actual time=125328.391..161800.298 rows=3252754 loops=1)
                           Buffers: shared hit=10795431 read=523673 written=1132
                           ->  Merge Join  (cost=2675157.69..3339908.29 rows=116 width=28) (actual time=125328.331..139555.718 rows=3252754 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=1018610 read=523673 written=1132
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.33 rows=8000000 width=12) (actual time=0.022..6693.352 rows=7999981 loops=1)
                                       Buffers: shared hit=267596 read=166613 written=1129
                                 ->  Sort  (cost=2675157.59..2682377.34 rows=2887900 width=28) (actual time=125328.206..128422.211 rows=3252754 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 352426kB
                                       Buffers: shared hit=751014 read=357060 written=3
                                       ->  Hash Join  (cost=66723.18..2365262.97 rows=2887900 width=28) (actual time=1403.634..119629.363 rows=3252754 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=751011 read=357060 written=3
                                             ->  Seq Scan on lineitem  (cost=0.00..1668603.40 rows=60105740 width=24) (actual time=0.050..22849.272 rows=60045603 loops=1)
                                                   Buffers: shared hit=711486 read=356060 written=3
                                             ->  Hash  (cost=65522.00..65522.00 rows=96094 width=4) (actual time=1403.086..1403.086 rows=108402 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3812kB
                                                   Buffers: shared hit=39522 read=1000
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=96094 width=4) (actual time=0.027..1336.129 rows=108402 loops=1)
                                                         Filter: ((p_name)::text ~~ '%dark%'::text)
                                                         Rows Removed by Filter: 1891598
                                                         Buffers: shared hit=39522 read=1000
                           ->  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=3252754)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9776821
                     ->  Index Only Scan using orders_o_orderkey_o_orderdate_idx on orders  (cost=0.00..1.94 rows=1 width=8) (actual time=0.019..0.020 rows=1 loops=3252754)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Heap Fetches: 3252754
                           Buffers: shared hit=12851339 read=177622 dirtied=133 written=494
               ->  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=3252754)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6505508
 Total runtime: 273421.599 ms
(44 rows)

COMMIT;
COMMIT