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 '%black%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                   QUERY PLAN                                                                                   
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3372224.02..3372228.36 rows=124 width=46) (actual time=433466.917..437012.715 rows=175 loops=1)
   Buffers: shared hit=30377501 read=604707 dirtied=1265 written=4994
   ->  Sort  (cost=3372224.02..3372224.33 rows=124 width=46) (actual time=433453.025..434462.191 rows=3267135 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 557745kB
         Buffers: shared hit=30377501 read=604707 dirtied=1265 written=4994
         ->  Nested Loop  (cost=2705347.85..3372219.71 rows=124 width=46) (actual time=152473.358..410568.661 rows=3267135 loops=1)
               Buffers: shared hit=30377493 read=604707 dirtied=1265 written=4994
               ->  Nested Loop  (cost=2705347.85..3372184.35 rows=124 width=24) (actual time=152473.276..379127.193 rows=3267135 loops=1)
                     Buffers: shared hit=23843223 read=604707 dirtied=1265 written=4994
                     ->  Nested Loop  (cost=2705347.85..3371942.36 rows=124 width=24) (actual time=152473.161..229627.776 rows=3267135 loops=1)
                           Buffers: shared hit=10977417 read=384118 dirtied=1056 written=1871
                           ->  Merge Join  (cost=2705347.85..3371906.26 rows=124 width=28) (actual time=152473.114..172268.850 rows=3267135 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=1158132 read=384118 dirtied=1056 written=1871
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.008..11251.397 rows=7999393 loops=1)
                                       Buffers: shared hit=313961 read=120215 written=849
                                 ->  Sort  (cost=2705347.72..2713170.17 rows=3128983 width=28) (actual time=152472.990..156083.558 rows=3267135 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 353549kB
                                       Buffers: shared hit=844171 read=263903 dirtied=1056 written=1022
                                       ->  Hash Join  (cost=66823.45..2367773.28 rows=3128983 width=28) (actual time=2476.425..146138.779 rows=3267135 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=844168 read=263903 dirtied=1056 written=1022
                                             ->  Seq Scan on lineitem  (cost=0.00..1668603.00 rows=60105700 width=24) (actual time=0.024..32217.498 rows=60045603 loops=1)
                                                   Buffers: shared hit=831742 read=235804 dirtied=1056 written=1022
                                             ->  Hash  (cost=65522.00..65522.00 rows=104116 width=4) (actual time=2476.066..2476.066 rows=108855 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3827kB
                                                   Buffers: shared hit=12423 read=28099
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=104116 width=4) (actual time=0.023..2387.022 rows=108855 loops=1)
                                                         Filter: ((p_name)::text ~~ '%black%'::text)
                                                         Rows Removed by Filter: 1891145
                                                         Buffers: shared hit=12423 read=28099
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.016..0.016 rows=1 loops=3267135)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9819285
                     ->  Index Only Scan using orders_o_orderkey_o_orderdate_idx on orders  (cost=0.00..1.94 rows=1 width=8) (actual time=0.044..0.045 rows=1 loops=3267135)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Heap Fetches: 3267135
                           Buffers: shared hit=12865806 read=220589 dirtied=209 written=3123
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.007..0.007 rows=1 loops=3267135)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6534270
 Total runtime: 437165.215 ms
(44 rows)

COMMIT;
COMMIT