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=3224579.47..3224582.97 rows=100 width=46) (actual time=182646.423..185697.068 rows=175 loops=1)
   Buffers: shared hit=30362442 read=623451 dirtied=829 written=28151
   ->  Sort  (cost=3224579.47..3224579.72 rows=100 width=46) (actual time=182634.581..183492.944 rows=3266895 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 557712kB
         Buffers: shared hit=30362442 read=623451 dirtied=829 written=28151
         ->  Nested Loop  (cost=2562617.29..3224576.15 rows=100 width=46) (actual time=93906.696..163874.707 rows=3266895 loops=1)
               Buffers: shared hit=30362434 read=623451 dirtied=829 written=28151
               ->  Nested Loop  (cost=2562617.29..3224547.63 rows=100 width=24) (actual time=93906.612..154594.434 rows=3266895 loops=1)
                     Buffers: shared hit=23828644 read=623451 dirtied=829 written=28151
                     ->  Nested Loop  (cost=2562617.29..3224350.51 rows=100 width=24) (actual time=93906.572..115049.889 rows=3266895 loops=1)
                           Buffers: shared hit=10743672 read=623194 dirtied=829 written=28105
                           ->  Merge Join  (cost=2562617.29..3224321.39 rows=100 width=28) (actual time=93906.516..103607.003 rows=3266895 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=925461 read=623194 dirtied=829 written=28105
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.015..4667.994 rows=7999993 loops=1)
                                       Buffers: shared hit=342875 read=91334 written=27286
                                 ->  Sort  (cost=2562615.12..2568819.81 rows=2481875 width=28) (actual time=93906.399..95926.033 rows=3266895 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 353531kB
                                       Buffers: shared hit=582586 read=531860 dirtied=829 written=819
                                       ->  Hash Join  (cost=66548.16..2299002.78 rows=2481875 width=28) (actual time=1157.076..90494.153 rows=3266895 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=582583 read=531860 dirtied=829 written=819
                                             ->  Seq Scan on lineitem  (cost=0.00..1678567.53 rows=60464953 width=24) (actual time=0.026..14773.979 rows=60044664 loops=1)
                                                   Buffers: shared hit=582578 read=491340 dirtied=829 written=819
                                             ->  Hash  (cost=65522.00..65522.00 rows=82093 width=4) (actual time=1156.852..1156.852 rows=108789 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3825kB
                                                   Buffers: shared hit=2 read=40520
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=82093 width=4) (actual time=0.022..1104.929 rows=108789 loops=1)
                                                         Filter: ((p_name)::text ~~ '%coral%'::text)
                                                         Rows Removed by Filter: 1891211
                                                         Buffers: shared hit=2 read=40520
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.003..0.003 rows=1 loops=3266895)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9818211
                     ->  Index Scan using pk_orders on orders  (cost=0.00..1.96 rows=1 width=8) (actual time=0.011..0.011 rows=1 loops=3266895)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Buffers: shared hit=13084972 read=257 written=46
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.001..0.002 rows=1 loops=3266895)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6533790
 Total runtime: 185815.560 ms
(43 rows)

COMMIT;
COMMIT