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 '%chiffon%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3655235.72..3655241.43 rows=163 width=46) (actual time=306492.820..309844.973 rows=175 loops=1)
   Buffers: shared hit=30011782 read=865807 written=5362
   ->  Sort  (cost=3655235.72..3655236.13 rows=163 width=46) (actual time=306479.743..307438.161 rows=3255106 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 556054kB
         Buffers: shared hit=30011782 read=865807 written=5362
         ->  Nested Loop  (cost=2981370.21..3655229.73 rows=163 width=46) (actual time=136046.542..285362.451 rows=3255106 loops=1)
               Buffers: shared hit=30011774 read=865807 written=5362
               ->  Nested Loop  (cost=2981370.21..3655183.24 rows=163 width=24) (actual time=136046.449..260668.847 rows=3255106 loops=1)
                     Buffers: shared hit=23501562 read=865807 written=5362
                     ->  Nested Loop  (cost=2981370.21..3654863.01 rows=163 width=24) (actual time=136046.402..181037.963 rows=3255106 loops=1)
                           Buffers: shared hit=10660047 read=669271 written=1637
                           ->  Merge Join  (cost=2981370.21..3654815.55 rows=163 width=28) (actual time=136046.352..151854.204 rows=3255106 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=877264 read=669271 written=1637
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.014..8325.044 rows=8000000 loops=1)
                                       Buffers: shared hit=298786 read=135423 written=1636
                                 ->  Sort  (cost=2981369.65..2991487.35 rows=4047080 width=28) (actual time=136046.212..138758.685 rows=3255106 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 352610kB
                                       Buffers: shared hit=578478 read=533848 written=1
                                       ->  Hash Join  (cost=67198.64..2537233.99 rows=4047080 width=28) (actual time=2154.443..131403.967 rows=3255106 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=578475 read=533848 written=1
                                             ->  Seq Scan on lineitem  (cost=0.00..1675249.80 rows=60345180 width=24) (actual time=0.029..27769.920 rows=60045826 loops=1)
                                                   Buffers: shared hit=578334 read=493464 written=1
                                             ->  Hash  (cost=65522.00..65522.00 rows=134131 width=4) (actual time=2154.152..2154.152 rows=108461 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3814kB
                                                   Buffers: shared hit=138 read=40384
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=134131 width=4) (actual time=0.036..2071.935 rows=108461 loops=1)
                                                         Filter: ((p_name)::text ~~ '%chiffon%'::text)
                                                         Rows Removed by Filter: 1891539
                                                         Buffers: shared hit=138 read=40384
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.007..0.008 rows=1 loops=3255106)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9782783
                     ->  Index Scan using pk_orders on orders  (cost=0.00..1.95 rows=1 width=8) (actual time=0.023..0.023 rows=1 loops=3255106)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Buffers: shared hit=12841515 read=196536 written=3725
               ->  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=3255106)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6510212
 Total runtime: 309959.681 ms
(43 rows)

COMMIT;
COMMIT