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 '%indian%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3374845.25..3374849.55 rows=123 width=46) (actual time=253820.227..257627.533 rows=175 loops=1)
   Buffers: shared hit=30041092 read=887301 dirtied=180 written=3813
   ->  Sort  (cost=3374845.25..3374845.55 rows=123 width=46) (actual time=253806.805..254942.970 rows=3260718 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 556843kB
         Buffers: shared hit=30041092 read=887301 dirtied=180 written=3813
         ->  Nested Loop  (cost=2708331.04..3374840.98 rows=123 width=46) (actual time=108544.977..230990.574 rows=3260718 loops=1)
               Buffers: shared hit=30041084 read=887301 dirtied=180 written=3813
               ->  Nested Loop  (cost=2708331.04..3374805.90 rows=123 width=24) (actual time=108544.901..212155.436 rows=3260718 loops=1)
                     Buffers: shared hit=23519648 read=887301 dirtied=180 written=3813
                     ->  Nested Loop  (cost=2708331.04..3374564.25 rows=123 width=24) (actual time=108544.761..144505.638 rows=3260718 loops=1)
                           Buffers: shared hit=10784713 read=561625 dirtied=1 written=1337
                           ->  Merge Join  (cost=2708331.04..3374528.43 rows=123 width=28) (actual time=108544.710..122402.063 rows=3260718 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=985989 read=560546 dirtied=1 written=1337
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.33 rows=8000000 width=12) (actual time=0.077..6917.391 rows=7999981 loops=1)
                                       Buffers: shared hit=276229 read=157980 written=1335
                                 ->  Sort  (cost=2708331.03..2716032.65 rows=3080649 width=28) (actual time=108544.518..111213.162 rows=3260718 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 353048kB
                                       Buffers: shared hit=709760 read=402566 dirtied=1 written=2
                                       ->  Hash Join  (cost=66798.25..2376317.12 rows=3080649 width=28) (actual time=1945.931..104273.260 rows=3260718 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=709757 read=402566 dirtied=1 written=2
                                             ->  Seq Scan on lineitem  (cost=0.00..1675255.19 rows=60345719 width=24) (actual time=0.024..19796.404 rows=60045826 loops=1)
                                                   Buffers: shared hit=709575 read=362223 dirtied=1 written=2
                                             ->  Hash  (cost=65522.00..65522.00 rows=102100 width=4) (actual time=1945.519..1945.519 rows=108505 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3815kB
                                                   Buffers: shared hit=179 read=40343
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=102100 width=4) (actual time=0.039..1863.611 rows=108505 loops=1)
                                                         Filter: ((p_name)::text ~~ '%indian%'::text)
                                                         Rows Removed by Filter: 1891495
                                                         Buffers: shared hit=179 read=40343
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.005..0.006 rows=1 loops=3260718)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9798724 read=1079
                     ->  Index Scan using pk_orders on orders  (cost=0.00..1.95 rows=1 width=8) (actual time=0.019..0.020 rows=1 loops=3260718)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Buffers: shared hit=12734935 read=325676 dirtied=179 written=2476
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.003..0.004 rows=1 loops=3260718)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6521436
 Total runtime: 257760.421 ms
(43 rows)

COMMIT;
COMMIT