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 '%royal%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3515944.53..3515949.50 rows=142 width=46) (actual time=376221.310..380145.355 rows=175 loops=1)
   Buffers: shared hit=30312546 read=652138 dirtied=746 written=1414
   ->  Sort  (cost=3515944.53..3515944.89 rows=142 width=46) (actual time=376208.266..377389.645 rows=3264615 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 557391kB
         Buffers: shared hit=30312546 read=652138 dirtied=746 written=1414
         ->  Nested Loop  (cost=2845747.42..3515939.46 rows=142 width=46) (actual time=169218.457..354014.940 rows=3264615 loops=1)
               Buffers: shared hit=30312538 read=652138 dirtied=746 written=1414
               ->  Nested Loop  (cost=2845747.42..3515898.96 rows=142 width=24) (actual time=169218.383..327697.369 rows=3264615 loops=1)
                     Buffers: shared hit=23783308 read=652138 dirtied=746 written=1414
                     ->  Nested Loop  (cost=2845747.42..3515619.99 rows=142 width=24) (actual time=169218.263..224684.020 rows=3264615 loops=1)
                           Buffers: shared hit=10735669 read=623242 dirtied=746 written=1383
                           ->  Merge Join  (cost=2845747.42..3515578.64 rows=142 width=28) (actual time=169218.225..183528.372 rows=3264615 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=923735 read=623242 dirtied=746 written=1383
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.040..6975.279 rows=7999941 loops=1)
                                       Buffers: shared hit=414616 read=19592 written=4
                                 ->  Sort  (cost=2845747.26..2854660.60 rows=3565337 width=28) (actual time=169218.129..171783.508 rows=3264615 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 353353kB
                                       Buffers: shared hit=509119 read=603650 dirtied=746 written=1379
                                       ->  Hash Join  (cost=66998.46..2457738.64 rows=3565337 width=28) (actual time=2211.181..165114.177 rows=3264615 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=509116 read=603650 dirtied=746 written=1379
                                             ->  Seq Scan on lineitem  (cost=0.00..1675928.91 rows=60369591 width=24) (actual time=0.032..46057.789 rows=59985687 loops=1)
                                                   Buffers: shared hit=495948 read=576293 dirtied=746 written=748
                                             ->  Hash  (cost=65522.00..65522.00 rows=118117 width=4) (actual time=2210.941..2210.941 rows=108805 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3826kB
                                                   Buffers: shared hit=13165 read=27357 written=631
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=118117 width=4) (actual time=0.031..2117.254 rows=108805 loops=1)
                                                         Filter: ((p_name)::text ~~ '%royal%'::text)
                                                         Rows Removed by Filter: 1891195
                                                         Buffers: shared hit=13165 read=27357 written=631
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.011..0.011 rows=1 loops=3264615)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9811934
                     ->  Index Only Scan using orders_o_orderkey_o_orderdate_idx on orders  (cost=0.00..1.95 rows=1 width=8) (actual time=0.030..0.030 rows=1 loops=3264615)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Heap Fetches: 3264615
                           Buffers: shared hit=13047639 read=28896 written=31
               ->  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=3264615)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6529230
 Total runtime: 380263.589 ms
(44 rows)

COMMIT;
COMMIT