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 '%powder%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                   QUERY PLAN                                                                                   
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3550833.51..3550838.65 rows=147 width=46) (actual time=413967.095..416800.025 rows=175 loops=1)
   Buffers: shared hit=29633748 read=1262908 dirtied=172 written=6787
   ->  Sort  (cost=3550833.51..3550833.87 rows=147 width=46) (actual time=413955.009..414707.055 rows=3256327 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 556225kB
         Buffers: shared hit=29633748 read=1262908 dirtied=172 written=6787
         ->  Nested Loop  (cost=2879532.57..3550828.21 rows=147 width=46) (actual time=159768.824..394076.336 rows=3256327 loops=1)
               Buffers: shared hit=29633740 read=1262908 dirtied=172 written=6787
               ->  Nested Loop  (cost=2879532.57..3550786.29 rows=147 width=24) (actual time=159768.748..367140.161 rows=3256327 loops=1)
                     Buffers: shared hit=23121086 read=1262908 dirtied=172 written=6787
                     ->  Nested Loop  (cost=2879532.57..3550494.10 rows=147 width=24) (actual time=159768.617..226251.103 rows=3256327 loops=1)
                           Buffers: shared hit=10553954 read=786867 written=6274
                           ->  Merge Join  (cost=2879532.57..3550451.29 rows=147 width=28) (actual time=159768.532..177720.233 rows=3256327 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=767137 read=786862 written=6274
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.093..10199.967 rows=8000000 loops=1)
                                       Buffers: shared hit=305907 read=128302 written=1809
                                 ->  Sort  (cost=2879532.40..2888808.23 rows=3710332 width=28) (actual time=159768.362..162712.107 rows=3256327 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 352705kB
                                       Buffers: shared hit=461230 read=658560 written=4465
                                       ->  Hash Join  (cost=67048.50..2474677.36 rows=3710332 width=28) (actual time=2169.394..154077.571 rows=3256327 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=461227 read=658560 written=4465
                                             ->  Seq Scan on lineitem  (cost=0.00..1686915.43 rows=60765343 width=24) (actual time=0.036..40505.211 rows=60045297 loops=1)
                                                   Buffers: shared hit=461222 read=618040 written=3
                                             ->  Hash  (cost=65522.00..65522.00 rows=122120 width=4) (actual time=2169.119..2169.119 rows=108553 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3817kB
                                                   Buffers: shared hit=2 read=40520 written=4462
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=122120 width=4) (actual time=0.028..1731.813 rows=108553 loops=1)
                                                         Filter: ((p_name)::text ~~ '%powder%'::text)
                                                         Rows Removed by Filter: 1891447
                                                         Buffers: shared hit=2 read=40520 written=4462
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.013..0.014 rows=1 loops=3256327)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9786817 read=5
                     ->  Index Only Scan using orders_o_orderkey_o_orderdate_idx on orders  (cost=0.00..1.98 rows=1 width=8) (actual time=0.042..0.042 rows=1 loops=3256327)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Heap Fetches: 3256327
                           Buffers: shared hit=12567132 read=476041 dirtied=172 written=513
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.005..0.006 rows=1 loops=3256327)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6512654
 Total runtime: 416902.532 ms
(44 rows)

COMMIT;
COMMIT