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 '%gainsboro%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                   QUERY PLAN                                                                                   
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3358811.73..3358815.93 rows=120 width=46) (actual time=699063.208..702139.885 rows=175 loops=1)
   Buffers: shared hit=30154642 read=633618 dirtied=55 written=2551
   ->  Sort  (cost=3358811.73..3358812.03 rows=120 width=46) (actual time=699044.725..699865.518 rows=3245450 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 554696kB
         Buffers: shared hit=30154642 read=633618 dirtied=55 written=2551
         ->  Nested Loop  (cost=2692827.44..3358807.59 rows=120 width=46) (actual time=200185.587..672984.341 rows=3245450 loops=1)
               Buffers: shared hit=30154634 read=633618 dirtied=55 written=2551
               ->  Nested Loop  (cost=2692827.44..3358773.36 rows=120 width=24) (actual time=200185.514..557139.027 rows=3245450 loops=1)
                     Buffers: shared hit=23663734 read=633618 dirtied=55 written=2551
                     ->  Nested Loop  (cost=2692827.44..3358538.79 rows=120 width=24) (actual time=200185.473..339890.870 rows=3245450 loops=1)
                           Buffers: shared hit=10798238 read=499591 written=724
                           ->  Merge Join  (cost=2692827.44..3358503.85 rows=120 width=28) (actual time=200185.432..224549.956 rows=3245450 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=1043753 read=499591 written=724
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.011..15371.850 rows=7999949 loops=1)
                                       Buffers: shared hit=346136 read=88072 written=723
                                 ->  Sort  (cost=2692827.41..2700355.41 rows=3011199 width=28) (actual time=200185.357..203721.119 rows=3245450 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 351855kB
                                       Buffers: shared hit=697617 read=411519 written=1
                                       ->  Hash Join  (cost=66773.23..2368793.70 rows=3011199 width=28) (actual time=4381.183..195839.200 rows=3245450 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=697614 read=411519 written=1
                                             ->  Seq Scan on lineitem  (cost=0.00..1670258.24 rows=60165024 width=24) (actual time=0.026..65936.629 rows=60045379 loops=1)
                                                   Buffers: shared hit=692490 read=376118 written=1
                                             ->  Hash  (cost=65522.00..65522.00 rows=100098 width=4) (actual time=4380.826..4380.826 rows=108037 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3799kB
                                                   Buffers: shared hit=5121 read=35401
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=100098 width=4) (actual time=0.019..4290.755 rows=108037 loops=1)
                                                         Filter: ((p_name)::text ~~ '%gainsboro%'::text)
                                                         Rows Removed by Filter: 1891963
                                                         Buffers: shared hit=5121 read=35401
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.034..0.034 rows=1 loops=3245450)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9754485
                     ->  Index Scan using pk_orders on orders  (cost=0.00..1.94 rows=1 width=8) (actual time=0.065..0.065 rows=1 loops=3245450)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Buffers: shared hit=12865496 read=134027 dirtied=55 written=1827
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.032..0.033 rows=1 loops=3245450)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6490900
 Total runtime: 702272.869 ms
(43 rows)

COMMIT;
COMMIT