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 '%lemon%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3388215.19..3388219.56 rows=125 width=46) (actual time=245787.219..249184.810 rows=175 loops=1)
   Buffers: shared hit=30271971 read=660107 dirtied=1073 written=4329
   ->  Sort  (cost=3388215.19..3388215.50 rows=125 width=46) (actual time=245772.341..246747.077 rows=3260945 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 556875kB
         Buffers: shared hit=30271971 read=660107 dirtied=1073 written=4329
         ->  Nested Loop  (cost=2721195.02..3388210.83 rows=125 width=46) (actual time=116289.472..224677.357 rows=3260945 loops=1)
               Buffers: shared hit=30271963 read=660107 dirtied=1073 written=4329
               ->  Nested Loop  (cost=2721195.02..3388175.18 rows=125 width=24) (actual time=116289.387..207891.178 rows=3260945 loops=1)
                     Buffers: shared hit=23750073 read=660107 dirtied=1073 written=4329
                     ->  Nested Loop  (cost=2721195.02..3387928.78 rows=125 width=24) (actual time=116289.338..147866.608 rows=3260945 loops=1)
                           Buffers: shared hit=10889962 read=458739 dirtied=1070 written=4262
                           ->  Merge Join  (cost=2721195.02..3387892.09 rows=126 width=28) (actual time=116289.279..128274.899 rows=3260945 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=1089916 read=458739 dirtied=1070 written=4262
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.33 rows=8000000 width=12) (actual time=0.023..5521.255 rows=7999997 loops=1)
                                       Buffers: shared hit=375233 read=58976 written=1026
                                 ->  Sort  (cost=2721195.02..2729063.19 rows=3147268 width=28) (actual time=116289.059..118700.161 rows=3260945 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 353066kB
                                       Buffers: shared hit=714683 read=399763 dirtied=1070 written=3236
                                       ->  Hash Join  (cost=66823.27..2381515.60 rows=3147268 width=28) (actual time=2148.810..111614.676 rows=3260945 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=714680 read=399763 dirtied=1070 written=3236
                                             ->  Seq Scan on lineitem  (cost=0.00..1678568.82 rows=60465082 width=24) (actual time=0.024..22140.118 rows=60044664 loops=1)
                                                   Buffers: shared hit=714675 read=359243 dirtied=1070
                                             ->  Hash  (cost=65522.00..65522.00 rows=104102 width=4) (actual time=2148.520..2148.520 rows=108627 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3819kB
                                                   Buffers: shared hit=2 read=40520 written=3236
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=104102 width=4) (actual time=0.030..2068.632 rows=108627 loops=1)
                                                         Filter: ((p_name)::text ~~ '%lemon%'::text)
                                                         Rows Removed by Filter: 1891373
                                                         Buffers: shared hit=2 read=40520 written=3236
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.005..0.005 rows=1 loops=3260945)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9800046
                     ->  Index Scan using pk_orders on orders  (cost=0.00..1.96 rows=1 width=8) (actual time=0.017..0.017 rows=1 loops=3260945)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Buffers: shared hit=12860111 read=201368 dirtied=3 written=67
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.003..0.003 rows=1 loops=3260945)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6521890
 Total runtime: 249269.826 ms
(43 rows)

COMMIT;
COMMIT