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=3495491.29..3495496.19 rows=140 width=46) (actual time=751049.876..754422.407 rows=175 loops=1)
   Buffers: shared hit=30245270 read=664079 dirtied=55 written=2799
   ->  Sort  (cost=3495491.29..3495491.64 rows=140 width=46) (actual time=751035.198..751967.871 rows=3258904 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 556588kB
         Buffers: shared hit=30245270 read=664079 dirtied=55 written=2799
         ->  Nested Loop  (cost=2825868.50..3495486.30 rows=140 width=46) (actual time=192581.657..729026.873 rows=3258904 loops=1)
               Buffers: shared hit=30245262 read=664079 dirtied=55 written=2799
               ->  Nested Loop  (cost=2825868.50..3495446.38 rows=140 width=24) (actual time=192581.569..597125.513 rows=3258904 loops=1)
                     Buffers: shared hit=23727454 read=664079 dirtied=55 written=2799
                     ->  Nested Loop  (cost=2825868.50..3495173.34 rows=140 width=24) (actual time=192580.740..351373.369 rows=3258904 loops=1)
                           Buffers: shared hit=10888056 read=449914 written=1373
                           ->  Merge Join  (cost=2825868.50..3495132.57 rows=140 width=28) (actual time=192578.347..221374.511 rows=3258904 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=1092413 read=449870 written=1373
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.008..18921.373 rows=7999985 loops=1)
                                       Buffers: shared hit=310670 read=123539 written=713
                                 ->  Sort  (cost=2825868.47..2834592.30 rows=3489529 width=28) (actual time=192578.153..196705.243 rows=3258904 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 352906kB
                                       Buffers: shared hit=781743 read=326331 written=660
                                       ->  Hash Join  (cost=66973.43..2446650.87 rows=3489529 width=28) (actual time=3398.998..186068.684 rows=3258904 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=781740 read=326331 written=660
                                             ->  Seq Scan on lineitem  (cost=0.00..1668598.31 rows=60105231 width=24) (actual time=0.031..60944.570 rows=59985329 loops=1)
                                                   Buffers: shared hit=758547 read=308999 written=2
                                             ->  Hash  (cost=65522.00..65522.00 rows=116114 width=4) (actual time=3398.603..3398.603 rows=108576 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3818kB
                                                   Buffers: shared hit=23190 read=17332 written=658
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=116114 width=4) (actual time=0.044..3320.334 rows=108576 loops=1)
                                                         Filter: ((p_name)::text ~~ '%tan%'::text)
                                                         Rows Removed by Filter: 1891424
                                                         Buffers: shared hit=23190 read=17332 written=658
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.038..0.038 rows=1 loops=3258904)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9795643 read=44
                     ->  Index Scan using pk_orders on orders  (cost=0.00..1.94 rows=1 width=8) (actual time=0.073..0.074 rows=1 loops=3258904)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Buffers: shared hit=12839398 read=214165 dirtied=55 written=1426
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.037..0.038 rows=1 loops=3258904)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6517808
 Total runtime: 754569.958 ms
(43 rows)

COMMIT;
COMMIT