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 '%khaki%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3377475.35..3377479.80 rows=127 width=46) (actual time=105298.448..108474.001 rows=175 loops=1)
   Buffers: shared hit=29975503 read=972242 written=7246
   ->  Sort  (cost=3377475.35..3377475.67 rows=127 width=46) (actual time=105285.000..106257.111 rows=3263418 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 557223kB
         Buffers: shared hit=29975503 read=972242 written=7246
         ->  Nested Loop  (cost=2710176.13..3377470.92 rows=127 width=46) (actual time=39040.392..88164.413 rows=3263418 loops=1)
               Buffers: shared hit=29975495 read=972242 written=7246
               ->  Nested Loop  (cost=2710176.13..3377434.69 rows=127 width=24) (actual time=39040.305..82335.698 rows=3263418 loops=1)
                     Buffers: shared hit=23448659 read=972242 written=7246
                     ->  Nested Loop  (cost=2710176.13..3377187.28 rows=127 width=24) (actual time=39040.118..53512.393 rows=3263418 loops=1)
                           Buffers: shared hit=10671477 read=677892 written=1833
                           ->  Merge Join  (cost=2710176.13..3377150.30 rows=127 width=28) (actual time=39039.991..45975.555 rows=3263418 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=863319 read=677892 written=1833
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.26 rows=8000000 width=12) (actual time=0.009..2748.209 rows=7999917 loops=1)
                                       Buffers: shared hit=416656 read=17552 written=1833
                                 ->  Sort  (cost=2710171.07..2718134.94 rows=3185547 width=28) (actual time=39039.884..40633.407 rows=3263418 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 353259kB
                                       Buffers: shared hit=446663 read=660340
                                       ->  Hash Join  (cost=66848.31..2366082.46 rows=3185547 width=28) (actual time=835.562..36096.475 rows=3263418 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=446660 read=660340
                                             ->  Seq Scan on lineitem  (cost=0.00..1666926.84 rows=60045184 width=24) (actual time=0.009..11100.720 rows=60045669 loops=1)
                                                   Buffers: shared hit=406135 read=660340
                                             ->  Hash  (cost=65522.00..65522.00 rows=106105 width=4) (actual time=835.341..835.341 rows=108775 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3825kB
                                                   Buffers: shared hit=40522
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=106105 width=4) (actual time=0.015..804.342 rows=108775 loops=1)
                                                         Filter: ((p_name)::text ~~ '%khaki%'::text)
                                                         Rows Removed by Filter: 1891225
                                                         Buffers: shared hit=40522
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.002..0.002 rows=1 loops=3263418)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9808158
                     ->  Index Scan using pk_orders on orders  (cost=0.00..1.94 rows=1 width=8) (actual time=0.008..0.008 rows=1 loops=3263418)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Buffers: shared hit=12777182 read=294350 written=5413
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.001..0.001 rows=1 loops=3263418)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6526836
 Total runtime: 108586.006 ms
(43 rows)

COMMIT;
COMMIT