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 '%lace%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3471372.64..3471377.29 rows=133 width=46) (actual time=346059.971..349502.588 rows=175 loops=1)
   Buffers: shared hit=30108179 read=816327 dirtied=29 written=2409
   ->  Sort  (cost=3471372.64..3471372.97 rows=133 width=46) (actual time=346034.461..347074.308 rows=3260784 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 556852kB
         Buffers: shared hit=30108179 read=816327 dirtied=29 written=2409
         ->  Nested Loop  (cost=2803121.80..3471367.95 rows=133 width=46) (actual time=143465.769..323651.168 rows=3260784 loops=1)
               Buffers: shared hit=30108171 read=816327 dirtied=29 written=2409
               ->  Nested Loop  (cost=2803121.80..3471330.02 rows=133 width=24) (actual time=143465.650..293726.838 rows=3260784 loops=1)
                     Buffers: shared hit=23586603 read=816327 dirtied=29 written=2409
                     ->  Nested Loop  (cost=2803121.80..3471070.47 rows=133 width=24) (actual time=143465.594..196363.456 rows=3260784 loops=1)
                           Buffers: shared hit=10710306 read=631601 written=1506
                           ->  Merge Join  (cost=2803121.80..3471031.74 rows=133 width=28) (actual time=143465.477..160168.258 rows=3260784 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=910681 read=631601 written=1506
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.025..8603.588 rows=7999925 loops=1)
                                       Buffers: shared hit=281175 read=153033 written=1499
                                 ->  Sort  (cost=2803121.24..2811393.90 rows=3309064 width=28) (actual time=143465.403..146764.692 rows=3260784 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 353053kB
                                       Buffers: shared hit=629506 read=478568 written=7
                                       ->  Hash Join  (cost=66898.35..2444782.84 rows=3309064 width=28) (actual time=1495.414..129185.667 rows=3260784 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=629503 read=478568 written=7
                                             ->  Seq Scan on lineitem  (cost=0.00..1668603.81 rows=60105781 width=24) (actual time=16.960..25317.576 rows=60045603 loops=1)
                                                   Buffers: shared hit=623019 read=444527 written=7
                                             ->  Hash  (cost=65522.00..65522.00 rows=110108 width=4) (actual time=1478.245..1478.245 rows=108577 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3818kB
                                                   Buffers: shared hit=6481 read=34041
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=110108 width=4) (actual time=0.027..1419.470 rows=108577 loops=1)
                                                         Filter: ((p_name)::text ~~ '%lace%'::text)
                                                         Rows Removed by Filter: 1891423
                                                         Buffers: shared hit=6481 read=34041
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.009..0.010 rows=1 loops=3260784)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9799625
                     ->  Index Scan using pk_orders on orders  (cost=0.00..1.94 rows=1 width=8) (actual time=0.028..0.029 rows=1 loops=3260784)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Buffers: shared hit=12876297 read=184726 dirtied=29 written=903
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.006..0.007 rows=1 loops=3260784)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6521568
 Total runtime: 349649.609 ms
(43 rows)

COMMIT;
COMMIT