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=3671535.30..3671541.14 rows=167 width=46) (actual time=698849.713..701817.604 rows=175 loops=1)
   Buffers: shared hit=30387823 read=605808 dirtied=17 written=2127
   ->  Sort  (cost=3671535.30..3671535.72 rows=167 width=46) (actual time=698837.132..699663.069 rows=3267872 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 557849kB
         Buffers: shared hit=30387823 read=605808 dirtied=17 written=2127
         ->  Nested Loop  (cost=2996753.03..3671529.13 rows=167 width=46) (actual time=192024.500..676905.889 rows=3267872 loops=1)
               Buffers: shared hit=30387815 read=605808 dirtied=17 written=2127
               ->  Nested Loop  (cost=2996753.03..3671481.51 rows=167 width=24) (actual time=192022.727..558243.362 rows=3267872 loops=1)
                     Buffers: shared hit=23852071 read=605808 dirtied=17 written=2127
                     ->  Nested Loop  (cost=2996753.03..3671153.42 rows=167 width=24) (actual time=192022.685..336070.023 rows=3267872 loops=1)
                           Buffers: shared hit=10854658 read=513597 written=598
                           ->  Merge Join  (cost=2996753.03..3671104.78 rows=167 width=28) (actual time=192022.639..216134.479 rows=3267872 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=1032937 read=513597 written=598
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.010..15246.840 rows=7999941 loops=1)
                                       Buffers: shared hit=355396 read=78812 written=589
                                 ->  Sort  (cost=2996753.00..3007172.63 rows=4167853 width=28) (actual time=192022.563..195484.863 rows=3267872 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 353607kB
                                       Buffers: shared hit=677541 read=434785 written=9
                                       ->  Hash Join  (cost=67248.69..2538479.37 rows=4167853 width=28) (actual time=3556.955..187617.879 rows=3267872 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=677538 read=434785 written=9
                                             ->  Seq Scan on lineitem  (cost=0.00..1675244.29 rows=60344629 width=24) (actual time=0.020..63892.383 rows=60045826 loops=1)
                                                   Buffers: shared hit=657863 read=413935 written=9
                                             ->  Hash  (cost=65522.00..65522.00 rows=138135 width=4) (actual time=3556.748..3556.748 rows=108805 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3826kB
                                                   Buffers: shared hit=19672 read=20850
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=138135 width=4) (actual time=0.271..3473.432 rows=108805 loops=1)
                                                         Filter: ((p_name)::text ~~ '%royal%'::text)
                                                         Rows Removed by Filter: 1891195
                                                         Buffers: shared hit=19672 read=20850
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.035..0.035 rows=1 loops=3267872)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9821721
                     ->  Index Scan using pk_orders on orders  (cost=0.00..1.95 rows=1 width=8) (actual time=0.066..0.066 rows=1 loops=3267872)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Buffers: shared hit=12997413 read=92211 dirtied=17 written=1529
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.033..0.034 rows=1 loops=3267872)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6535744
 Total runtime: 701938.357 ms
(43 rows)

COMMIT;
COMMIT