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 '%coral%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3331370.39..3331374.31 rows=112 width=46) (actual time=236215.322..239522.336 rows=175 loops=1)
   Buffers: shared hit=30023860 read=927759 dirtied=256 written=4137
   ->  Sort  (cost=3331370.39..3331370.67 rows=112 width=46) (actual time=236200.999..237173.405 rows=3263828 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 557280kB
         Buffers: shared hit=30023860 read=927759 dirtied=256 written=4137
         ->  Nested Loop  (cost=2666792.43..3331366.57 rows=112 width=46) (actual time=103137.116..215350.421 rows=3263828 loops=1)
               Buffers: shared hit=30023852 read=927759 dirtied=256 written=4137
               ->  Nested Loop  (cost=2666792.43..3331334.63 rows=112 width=24) (actual time=103137.033..199192.246 rows=3263828 loops=1)
                     Buffers: shared hit=23496196 read=927759 dirtied=256 written=4137
                     ->  Nested Loop  (cost=2666792.43..3331116.44 rows=112 width=24) (actual time=103136.936..135044.126 rows=3263828 loops=1)
                           Buffers: shared hit=10869931 read=480976 written=1655
                           ->  Merge Join  (cost=2666792.43..3331083.83 rows=112 width=28) (actual time=103136.871..116248.826 rows=3263828 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=1062833 read=479088 written=1653
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.007..6029.790 rows=7999993 loops=1)
                                       Buffers: shared hit=257382 read=176827 written=1298
                                 ->  Sort  (cost=2666792.43..2673860.23 rows=2827120 width=28) (actual time=103136.774..106093.552 rows=3263828 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 353291kB
                                       Buffers: shared hit=805451 read=302261 written=355
                                       ->  Hash Join  (cost=66698.30..2363853.78 rows=2827120 width=28) (actual time=1156.458..96952.907 rows=3263828 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=805448 read=302261 written=355
                                             ->  Seq Scan on lineitem  (cost=0.00..1668034.14 rows=60085014 width=24) (actual time=0.039..18090.071 rows=59985329 loops=1)
                                                   Buffers: shared hit=776090 read=291094 written=7
                                             ->  Hash  (cost=65522.00..65522.00 rows=94104 width=4) (actual time=1156.231..1156.231 rows=108789 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3825kB
                                                   Buffers: shared hit=29355 read=11167 written=348
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=94104 width=4) (actual time=0.020..1100.300 rows=108789 loops=1)
                                                         Filter: ((p_name)::text ~~ '%coral%'::text)
                                                         Rows Removed by Filter: 1891211
                                                         Buffers: shared hit=29355 read=11167 written=348
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.004..0.005 rows=1 loops=3263828)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9807098 read=1888 written=2
                     ->  Index Only Scan using orders_o_orderkey_o_orderdate_idx on orders  (cost=0.00..1.94 rows=1 width=8) (actual time=0.018..0.019 rows=1 loops=3263828)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Heap Fetches: 3263828
                           Buffers: shared hit=12626265 read=446783 dirtied=256 written=2482
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.003..0.003 rows=1 loops=3263828)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6527656
 Total runtime: 239651.609 ms
(44 rows)

COMMIT;
COMMIT