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 '%floral%'
	) as profit
group by
	nation,
	o_year
order by
	nation,
	o_year desc;
                                                                                  QUERY PLAN                                                                                   
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 GroupAggregate  (cost=3470402.34..3470406.96 rows=132 width=46) (actual time=276385.498..279873.523 rows=175 loops=1)
   Buffers: shared hit=29943551 read=768340 dirtied=135 written=2639
   ->  Sort  (cost=3470402.34..3470402.67 rows=132 width=46) (actual time=276371.857..277480.124 rows=3237167 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 553531kB
         Buffers: shared hit=29943551 read=768340 dirtied=135 written=2639
         ->  Nested Loop  (cost=2802163.60..3470397.69 rows=132 width=46) (actual time=127485.874..255628.888 rows=3237167 loops=1)
               Buffers: shared hit=29943543 read=768340 dirtied=135 written=2639
               ->  Nested Loop  (cost=2802163.60..3470360.05 rows=132 width=24) (actual time=127485.796..235478.316 rows=3237167 loops=1)
                     Buffers: shared hit=23469209 read=768340 dirtied=135 written=2639
                     ->  Nested Loop  (cost=2802163.60..3470102.89 rows=132 width=24) (actual time=127485.683..164609.361 rows=3237167 loops=1)
                           Buffers: shared hit=10714833 read=556167 written=2134
                           ->  Merge Join  (cost=2802163.60..3470064.45 rows=132 width=28) (actual time=127485.630..142078.960 rows=3237167 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=986172 read=555734 written=2134
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.33 rows=8000000 width=12) (actual time=0.022..6894.700 rows=7999861 loops=1)
                                       Buffers: shared hit=263238 read=170964 written=1157
                                 ->  Sort  (cost=2802163.49..2810433.27 rows=3307915 width=28) (actual time=127485.535..130654.212 rows=3237167 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 351208kB
                                       Buffers: shared hit=722934 read=384770 written=977
                                       ->  Hash Join  (cost=66898.35..2443957.79 rows=3307915 width=28) (actual time=1374.937..121715.081 rows=3237167 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=722931 read=384770 written=977
                                             ->  Seq Scan on lineitem  (cost=0.00..1668025.08 rows=60084908 width=24) (actual time=0.037..22737.224 rows=59985329 loops=1)
                                                   Buffers: shared hit=692920 read=374256 written=5
                                             ->  Hash  (cost=65522.00..65522.00 rows=110108 width=4) (actual time=1374.605..1374.605 rows=107877 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3793kB
                                                   Buffers: shared hit=30008 read=10514 written=972
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=110108 width=4) (actual time=0.032..1304.751 rows=107877 loops=1)
                                                         Filter: ((p_name)::text ~~ '%floral%'::text)
                                                         Rows Removed by Filter: 1892123
                                                         Buffers: shared hit=30008 read=10514 written=972
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.005..0.006 rows=1 loops=3237167)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9728661 read=433
                     ->  Index Only Scan using orders_o_orderkey_o_orderdate_idx on orders  (cost=0.00..1.94 rows=1 width=8) (actual time=0.020..0.021 rows=1 loops=3237167)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Heap Fetches: 3237167
                           Buffers: shared hit=12754376 read=212173 dirtied=135 written=505
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.004..0.004 rows=1 loops=3237167)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6474334
 Total runtime: 280046.474 ms
(44 rows)

COMMIT;
COMMIT