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 '%cornsilk%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3353393.47..3353397.49 rows=115 width=46) (actual time=367529.828..370770.178 rows=175 loops=1)
   Buffers: shared hit=30493835 read=504473 dirtied=7 written=1941
   ->  Sort  (cost=3353393.47..3353393.75 rows=115 width=46) (actual time=367516.730..368415.199 rows=3268289 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 557908kB
         Buffers: shared hit=30493835 read=504473 dirtied=7 written=1941
         ->  Nested Loop  (cost=2688238.79..3353389.53 rows=115 width=46) (actual time=165654.353..344845.460 rows=3268289 loops=1)
               Buffers: shared hit=30493827 read=504473 dirtied=7 written=1941
               ->  Nested Loop  (cost=2688238.79..3353356.73 rows=115 width=24) (actual time=165654.265..319637.146 rows=3268289 loops=1)
                     Buffers: shared hit=23957249 read=504473 dirtied=7 written=1941
                     ->  Nested Loop  (cost=2688238.79..3353130.42 rows=115 width=24) (actual time=165654.127..221176.065 rows=3268289 loops=1)
                           Buffers: shared hit=10885780 read=484893 written=1920
                           ->  Merge Join  (cost=2688238.79..3353096.94 rows=115 width=28) (actual time=165654.073..182697.424 rows=3268289 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=1062693 read=484893 written=1920
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.463..9610.131 rows=7999853 loops=1)
                                       Buffers: shared hit=295134 read=139068 written=1918
                                 ->  Sort  (cost=2688238.66..2695494.39 rows=2902293 width=28) (actual time=165653.551..168348.870 rows=3268289 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 353640kB
                                       Buffers: shared hit=767559 read=345825 written=2
                                       ->  Hash Join  (cost=66723.19..2376695.48 rows=2902293 width=28) (actual time=3030.572..160232.779 rows=3268289 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=767556 read=345825 written=2
                                             ->  Seq Scan on lineitem  (cost=0.00..1676902.68 rows=60404668 width=24) (actual time=0.102..42467.469 rows=60045310 loops=1)
                                                   Buffers: shared hit=767551 read=305305 written=2
                                             ->  Hash  (cost=65522.00..65522.00 rows=96095 width=4) (actual time=3029.810..3029.810 rows=108871 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3828kB
                                                   Buffers: shared hit=2 read=40520
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=96095 width=4) (actual time=0.018..2938.328 rows=108871 loops=1)
                                                         Filter: ((p_name)::text ~~ '%cornsilk%'::text)
                                                         Rows Removed by Filter: 1891129
                                                         Buffers: shared hit=2 read=40520
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.010..0.011 rows=1 loops=3268289)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9823087
                     ->  Index Only Scan using orders_o_orderkey_o_orderdate_idx on orders  (cost=0.00..1.96 rows=1 width=8) (actual time=0.029..0.029 rows=1 loops=3268289)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Heap Fetches: 3268289
                           Buffers: shared hit=13071469 read=19580 dirtied=7 written=21
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.005..0.005 rows=1 loops=3268289)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6536578
 Total runtime: 370882.519 ms
(44 rows)

COMMIT;
COMMIT