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 '%forest%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3624364.53..3624369.81 rows=151 width=46) (actual time=223235.741..226514.241 rows=175 loops=1)
   Buffers: shared hit=30288011 read=588521 written=7671
   ->  Sort  (cost=3624364.53..3624364.91 rows=151 width=46) (actual time=223218.584..224188.508 rows=3254895 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 556024kB
         Buffers: shared hit=30288011 read=588521 written=7671
         ->  Nested Loop  (cost=2952327.39..3624359.06 rows=151 width=46) (actual time=108801.953..204011.224 rows=3254895 loops=1)
               Buffers: shared hit=30288003 read=588521 written=7671
               ->  Nested Loop  (cost=2952327.39..3624316.00 rows=151 width=24) (actual time=108801.828..188730.824 rows=3254895 loops=1)
                     Buffers: shared hit=23778213 read=588521 written=7671
                     ->  Nested Loop  (cost=2952327.39..3624019.34 rows=151 width=24) (actual time=108801.691..138001.848 rows=3254895 loops=1)
                           Buffers: shared hit=10770892 read=558510 written=7663
                           ->  Merge Join  (cost=2952327.39..3623975.37 rows=151 width=28) (actual time=108801.636..120647.762 rows=3254895 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=988638 read=558510 written=7663
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.009..5810.487 rows=7999977 loops=1)
                                       Buffers: shared hit=266482 read=167727 written=3089
                                 ->  Sort  (cost=2952327.39..2961847.26 rows=3807947 width=28) (actual time=108801.543..110939.118 rows=3254895 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 352593kB
                                       Buffers: shared hit=722156 read=390783 written=4574
                                       ->  Hash Join  (cost=67098.69..2536107.70 rows=3807947 width=28) (actual time=1779.686..105330.228 rows=3254895 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=722153 read=390783 written=4574
                                             ->  Seq Scan on lineitem  (cost=0.00..1676193.13 rows=60378913 width=24) (actual time=0.054..18124.270 rows=59985687 loops=1)
                                                   Buffers: shared hit=716772 read=355639 written=6
                                             ->  Hash  (cost=65522.00..65522.00 rows=126135 width=4) (actual time=1779.095..1779.095 rows=108543 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3816kB
                                                   Buffers: shared hit=5378 read=35144 written=4568
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=126135 width=4) (actual time=0.019..1704.203 rows=108543 loops=1)
                                                         Filter: ((p_name)::text ~~ '%forest%'::text)
                                                         Rows Removed by Filter: 1891457
                                                         Buffers: shared hit=5378 read=35144 written=4568
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.004..0.004 rows=1 loops=3254895)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9782254
                     ->  Index Only Scan using orders_o_orderkey_o_orderdate_idx on orders  (cost=0.00..1.95 rows=1 width=8) (actual time=0.014..0.015 rows=1 loops=3254895)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Heap Fetches: 3254895
                           Buffers: shared hit=13007321 read=30011 written=8
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.002..0.003 rows=1 loops=3254895)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6509790
 Total runtime: 226611.245 ms
(44 rows)

COMMIT;
COMMIT