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 '%tan%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3504103.10..3504107.97 rows=139 width=46) (actual time=177188.948..180456.789 rows=175 loops=1)
   Buffers: shared hit=30369118 read=543914 dirtied=35 written=7160
   ->  Sort  (cost=3504103.10..3504103.45 rows=139 width=46) (actual time=177175.806..178135.558 rows=3258627 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 556549kB
         Buffers: shared hit=30369118 read=543914 dirtied=35 written=7160
         ->  Nested Loop  (cost=2834778.53..3504098.15 rows=139 width=46) (actual time=94950.119..159420.047 rows=3258627 loops=1)
               Buffers: shared hit=30369110 read=543914 dirtied=35 written=7160
               ->  Nested Loop  (cost=2834778.53..3504058.51 rows=139 width=24) (actual time=94950.037..150902.680 rows=3258627 loops=1)
                     Buffers: shared hit=23851856 read=543914 dirtied=35 written=7160
                     ->  Nested Loop  (cost=2834778.53..3503784.98 rows=139 width=24) (actual time=94949.993..114031.093 rows=3258627 loops=1)
                           Buffers: shared hit=10818488 read=524963 written=6673
                           ->  Merge Join  (cost=2834778.53..3503744.50 rows=139 width=28) (actual time=94949.933..103506.852 rows=3258627 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=1023646 read=524963 written=6673
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.009..3749.442 rows=7999985 loops=1)
                                       Buffers: shared hit=347089 read=87120 written=2804
                                 ->  Sort  (cost=2834776.36..2843401.55 rows=3450078 width=28) (actual time=94949.751..96922.849 rows=3258627 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 352885kB
                                       Buffers: shared hit=676557 read=437843 written=3869
                                       ->  Hash Join  (cost=66948.55..2460128.98 rows=3450078 width=28) (actual time=1484.375..90317.121 rows=3258627 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=676554 read=437843 written=3869
                                             ->  Seq Scan on lineitem  (cost=0.00..1678483.13 rows=60461913 width=24) (actual time=0.023..15485.796 rows=59984909 loops=1)
                                                   Buffers: shared hit=669179 read=404693 written=11
                                             ->  Hash  (cost=65522.00..65522.00 rows=114124 width=4) (actual time=1484.129..1484.129 rows=108576 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3818kB
                                                   Buffers: shared hit=7372 read=33150 written=3858
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=114124 width=4) (actual time=0.022..1420.054 rows=108576 loops=1)
                                                         Filter: ((p_name)::text ~~ '%tan%'::text)
                                                         Rows Removed by Filter: 1891424
                                                         Buffers: shared hit=7372 read=33150 written=3858
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.002..0.003 rows=1 loops=3258627)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9794842
                     ->  Index Scan using pk_orders on orders  (cost=0.00..1.96 rows=1 width=8) (actual time=0.010..0.011 rows=1 loops=3258627)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Buffers: shared hit=13033368 read=18951 dirtied=35 written=487
               ->  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=3258627)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6517254
 Total runtime: 180620.630 ms
(43 rows)

COMMIT;
COMMIT