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 '%slate%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                               QUERY PLAN                                                                
-----------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3337544.97..3337548.96 rows=114 width=46)
   ->  Sort  (cost=3337544.97..3337545.25 rows=114 width=46)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         ->  Nested Loop  (cost=2672524.22..3337541.07 rows=114 width=46)
               ->  Nested Loop  (cost=2672524.22..3337508.56 rows=114 width=24)
                     ->  Nested Loop  (cost=2672524.22..3337286.47 rows=114 width=24)
                           ->  Merge Join  (cost=2672524.22..3337253.27 rows=114 width=28)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12)
                                 ->  Sort  (cost=2672524.14..2679736.67 rows=2885011 width=28)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       ->  Hash Join  (cost=66723.18..2362960.36 rows=2885011 width=28)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             ->  Seq Scan on lineitem  (cost=0.00..1666931.04 rows=60045604 width=24)
                                             ->  Hash  (cost=65522.00..65522.00 rows=96094 width=4)
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=96094 width=4)
                                                         Filter: ((p_name)::text ~~ '%slate%'::text)
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                     ->  Index Scan using pk_orders on orders  (cost=0.00..1.94 rows=1 width=8)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
(23 rows)

COMMIT;
COMMIT