BEGIN;
BEGIN
EXPLAIN
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 '%seashell%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                    QUERY PLAN                                                                    
--------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=1380979.62..1380985.15 rows=158 width=46)
   Group Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
   ->  Sort  (cost=1380979.62..1380980.02 rows=158 width=46)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         ->  Hash Join  (cost=67176.48..1380973.85 rows=158 width=46)
               Hash Cond: (supplier.s_nationkey = nation.n_nationkey)
               ->  Nested Loop  (cost=67174.92..1380969.33 rows=158 width=24)
                     ->  Nested Loop  (cost=67174.48..1380892.75 rows=158 width=24)
                           ->  Nested Loop  (cost=67174.19..1380841.77 rows=158 width=28)
                                 ->  Hash Join  (cost=67173.62..353388.67 rows=525705 width=16)
                                       Hash Cond: (partsupp.ps_partkey = part.p_partkey)
                                       ->  Seq Scan on partsupp  (cost=0.00..250958.00 rows=8000000 width=12)
                                       ->  Hash  (cost=65522.00..65522.00 rows=132130 width=4)
                                             ->  Seq Scan on part  (cost=0.00..65522.00 rows=132130 width=4)
                                                   Filter: ((p_name)::text ~~ '%seashell%'::text)
                                 ->  Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem  (cost=0.56..1.94 rows=1 width=24)
                                       Index Cond: (l_partkey = partsupp.ps_partkey)
                                       Filter: (partsupp.ps_suppkey = l_suppkey)
                           ->  Index Scan using pk_supplier on supplier  (cost=0.29..0.31 rows=1 width=8)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                     ->  Index Only Scan using orders_o_orderkey_o_orderdate_idx on orders  (cost=0.43..0.47 rows=1 width=8)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
               ->  Hash  (cost=1.25..1.25 rows=25 width=30)
                     ->  Seq Scan on nation  (cost=0.00..1.25 rows=25 width=30)
 Planning time: 34.358 ms
(25 rows)

COMMIT;
COMMIT