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 '%chocolate%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                           QUERY PLAN                                                                                            
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=1215041.92..1215046.58 rows=133 width=46) (actual time=89811.655..92486.250 rows=175 loops=1)
   Group Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
   Buffers: shared hit=35761248 read=2459331 dirtied=18894 written=2336
   ->  Sort  (cost=1215041.92..1215042.25 rows=133 width=46) (actual time=89801.399..90472.179 rows=3284381 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 560171kB
         Buffers: shared hit=35761248 read=2459331 dirtied=18894 written=2336
         ->  Hash Join  (cost=66901.21..1215037.23 rows=133 width=46) (actual time=819.106..81177.337 rows=3284381 loops=1)
               Hash Cond: (supplier.s_nationkey = nation.n_nationkey)
               Buffers: shared hit=35761240 read=2459331 dirtied=18894 written=2336
               ->  Nested Loop  (cost=66899.64..1215033.17 rows=133 width=24) (actual time=819.039..78329.623 rows=3284381 loops=1)
                     Buffers: shared hit=35761236 read=2459331 dirtied=18894 written=2336
                     ->  Nested Loop  (cost=66899.21..1214968.71 rows=133 width=24) (actual time=818.930..43129.110 rows=3284381 loops=1)
                           Buffers: shared hit=23457336 read=1607860 dirtied=18828 written=1459
                           ->  Nested Loop  (cost=66898.92..1214925.80 rows=133 width=28) (actual time=818.917..33321.325 rows=3284381 loops=1)
                                 Buffers: shared hit=13586240 read=1607860 dirtied=18828 written=1459
                                 ->  Hash Join  (cost=66898.35..352260.67 rows=440432 width=16) (actual time=818.857..4400.590 rows=437476 loops=1)
                                       Hash Cond: (partsupp.ps_partkey = part.p_partkey)
                                       Buffers: shared hit=99316 read=112164 written=31
                                       ->  Seq Scan on partsupp  (cost=0.00..250958.00 rows=8000000 width=12) (actual time=0.002..2055.465 rows=8000000 loops=1)
                                             Buffers: shared hit=82038 read=88920 written=31
                                       ->  Hash  (cost=65522.00..65522.00 rows=110108 width=4) (actual time=818.280..818.280 rows=109369 loops=1)
                                             Buckets: 131072  Batches: 1  Memory Usage: 4870kB
                                             Buffers: shared hit=17278 read=23244
                                             ->  Seq Scan on part  (cost=0.00..65522.00 rows=110108 width=4) (actual time=0.015..780.097 rows=109369 loops=1)
                                                   Filter: ((p_name)::text ~~ '%chocolate%'::text)
                                                   Rows Removed by Filter: 1890631
                                                   Buffers: shared hit=17278 read=23244
                                 ->  Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem  (cost=0.56..1.95 rows=1 width=24) (actual time=0.013..0.064 rows=8 loops=437476)
                                       Index Cond: (l_partkey = partsupp.ps_partkey)
                                       Filter: (partsupp.ps_suppkey = l_suppkey)
                                       Rows Removed by Filter: 23
                                       Buffers: shared hit=13486924 read=1495696 dirtied=18828 written=1428
                           ->  Index Scan using pk_supplier on supplier  (cost=0.29..0.31 rows=1 width=8) (actual time=0.002..0.002 rows=1 loops=3284381)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9871096
                     ->  Index Only Scan using orders_o_orderkey_o_orderdate_idx on orders  (cost=0.43..0.47 rows=1 width=8) (actual time=0.010..0.010 rows=1 loops=3284381)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Heap Fetches: 3284381
                           Buffers: shared hit=12303900 read=851471 dirtied=66 written=877
               ->  Hash  (cost=1.25..1.25 rows=25 width=30) (actual time=0.020..0.020 rows=25 loops=1)
                     Buckets: 1024  Batches: 1  Memory Usage: 10kB
                     Buffers: shared hit=1
                     ->  Seq Scan on nation  (cost=0.00..1.25 rows=25 width=30) (actual time=0.005..0.007 rows=25 loops=1)
                           Buffers: shared hit=1
 Planning time: 28.388 ms
 Execution time: 92525.944 ms
(47 rows)

COMMIT;
COMMIT