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 '%linen%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                   QUERY PLAN                                                                                   
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3643137.35..3643142.71 rows=153 width=46) (actual time=666151.967..669013.694 rows=175 loops=1)
   Buffers: shared hit=30023457 read=873678 dirtied=40 written=2493
   ->  Sort  (cost=3643137.35..3643137.74 rows=153 width=46) (actual time=666138.833..666935.131 rows=3256404 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 556236kB
         Buffers: shared hit=30023457 read=873678 dirtied=40 written=2493
         ->  Nested Loop  (cost=2970907.11..3643131.80 rows=153 width=46) (actual time=202717.206..645860.645 rows=3256404 loops=1)
               Buffers: shared hit=30023449 read=873678 dirtied=40 written=2493
               ->  Nested Loop  (cost=2970907.11..3643088.17 rows=153 width=24) (actual time=202717.102..539621.313 rows=3256404 loops=1)
                     Buffers: shared hit=23510641 read=873678 dirtied=40 written=2493
                     ->  Nested Loop  (cost=2970907.11..3642784.05 rows=153 width=24) (actual time=202717.052..331351.801 rows=3256404 loops=1)
                           Buffers: shared hit=10758294 read=582750 written=565
                           ->  Merge Join  (cost=2970907.11..3642739.49 rows=153 width=28) (actual time=202717.015..226055.006 rows=3256404 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=971248 read=582750 written=565
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.009..14636.656 rows=7999945 loops=1)
                                       Buffers: shared hit=357829 read=76379 written=563
                                 ->  Sort  (cost=2970907.08..2980486.97 rows=3831954 width=28) (actual time=202716.944..206000.055 rows=3256404 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 352711kB
                                       Buffers: shared hit=613419 read=506371 written=2
                                       ->  Hash Join  (cost=67098.55..2551889.64 rows=3831954 width=28) (actual time=4022.192..197805.033 rows=3256404 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=613416 read=506371 written=2
                                             ->  Seq Scan on lineitem  (cost=0.00..1686910.69 rows=60764869 width=24) (actual time=0.018..71798.948 rows=60045297 loops=1)
                                                   Buffers: shared hit=602989 read=476273 written=2
                                             ->  Hash  (cost=65522.00..65522.00 rows=126124 width=4) (actual time=4021.953..4021.953 rows=108491 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3815kB
                                                   Buffers: shared hit=10424 read=30098
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=126124 width=4) (actual time=0.019..3931.965 rows=108491 loops=1)
                                                         Filter: ((p_name)::text ~~ '%linen%'::text)
                                                         Rows Removed by Filter: 1891509
                                                         Buffers: shared hit=10424 read=30098
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.030..0.031 rows=1 loops=3256404)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9787046
                     ->  Index Scan using pk_orders on orders  (cost=0.00..1.98 rows=1 width=8) (actual time=0.062..0.062 rows=1 loops=3256404)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Buffers: shared hit=12752347 read=290928 dirtied=40 written=1928
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.029..0.030 rows=1 loops=3256404)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6512808
 Total runtime: 669116.594 ms
(43 rows)

COMMIT;
COMMIT