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 '%forest%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                           QUERY PLAN                                                                                            
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=1245165.48..1245170.31 rows=138 width=46) (actual time=135958.848..139832.218 rows=175 loops=1)
   Group Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
   Buffers: shared hit=35632218 read=2282676 dirtied=3676 written=11524
   ->  Sort  (cost=1245165.48..1245165.82 rows=138 width=46) (actual time=135945.423..137361.591 rows=3257970 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 556457kB
         Buffers: shared hit=35632218 read=2282676 dirtied=3676 written=11524
         ->  Hash Join  (cost=66951.24..1245160.57 rows=138 width=46) (actual time=961.152..118831.457 rows=3257970 loops=1)
               Hash Cond: (supplier.s_nationkey = nation.n_nationkey)
               Buffers: shared hit=35632210 read=2282676 dirtied=3676 written=11524
               ->  Nested Loop  (cost=66949.68..1245156.42 rows=138 width=24) (actual time=961.080..115000.156 rows=3257970 loops=1)
                     Buffers: shared hit=35632206 read=2282676 dirtied=3676 written=11524
                     ->  Nested Loop  (cost=66949.24..1245089.54 rows=138 width=24) (actual time=960.989..61799.041 rows=3257970 loops=1)
                           Buffers: shared hit=23285362 read=1579828 dirtied=3561 written=7988
                           ->  Nested Loop  (cost=66948.95..1245045.02 rows=138 width=28) (actual time=960.970..47823.065 rows=3257970 loops=1)
                                 Buffers: shared hit=13493866 read=1579828 dirtied=3561 written=7988
                                 ->  Hash Join  (cost=66948.39..352470.83 rows=456444 width=16) (actual time=960.800..7401.924 rows=434172 loops=1)
                                       Hash Cond: (partsupp.ps_partkey = part.p_partkey)
                                       Buffers: shared hit=68626 read=142854 written=663
                                       ->  Seq Scan on partsupp  (cost=0.00..250958.00 rows=8000000 width=12) (actual time=0.007..3561.637 rows=8000000 loops=1)
                                             Buffers: shared hit=46707 read=124251 written=663
                                       ->  Hash  (cost=65522.00..65522.00 rows=114111 width=4) (actual time=959.928..959.928 rows=108543 loops=1)
                                             Buckets: 131072  Batches: 1  Memory Usage: 4840kB
                                             Buffers: shared hit=21919 read=18603
                                             ->  Seq Scan on part  (cost=0.00..65522.00 rows=114111 width=4) (actual time=0.012..912.518 rows=108543 loops=1)
                                                   Filter: ((p_name)::text ~~ '%forest%'::text)
                                                   Rows Removed by Filter: 1891457
                                                   Buffers: shared hit=21919 read=18603
                                 ->  Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem  (cost=0.56..1.95 rows=1 width=24) (actual time=0.019..0.090 rows=8 loops=434172)
                                       Index Cond: (l_partkey = partsupp.ps_partkey)
                                       Filter: (partsupp.ps_suppkey = l_suppkey)
                                       Rows Removed by Filter: 23
                                       Buffers: shared hit=13425240 read=1436974 dirtied=3561 written=7325
                           ->  Index Scan using pk_supplier on supplier  (cost=0.29..0.31 rows=1 width=8) (actual time=0.003..0.003 rows=1 loops=3257970)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9791496
                     ->  Index Only Scan using orders_o_orderkey_o_orderdate_idx on orders  (cost=0.43..0.47 rows=1 width=8) (actual time=0.015..0.016 rows=1 loops=3257970)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Heap Fetches: 3257970
                           Buffers: shared hit=12346844 read=702848 dirtied=115 written=3536
               ->  Hash  (cost=1.25..1.25 rows=25 width=30) (actual time=0.023..0.023 rows=25 loops=1)
                     Buckets: 1024  Batches: 1  Memory Usage: 10kB
                     Buffers: shared hit=1
                     ->  Seq Scan on nation  (cost=0.00..1.25 rows=25 width=30) (actual time=0.007..0.011 rows=25 loops=1)
                           Buffers: shared hit=1
 Planning time: 34.240 ms
 Execution time: 139896.720 ms
(47 rows)

COMMIT;
COMMIT