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=3474141.33..3474145.95 rows=132 width=46) (actual time=457747.300..461289.963 rows=175 loops=1)
   Buffers: shared hit=30274635 read=664163 dirtied=13 written=3040
   ->  Sort  (cost=3474141.33..3474141.66 rows=132 width=46) (actual time=457733.717..458799.047 rows=3262059 loops=1)
         Sort Key: nation.n_name, (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone))
         Sort Method: quicksort  Memory: 557032kB
         Buffers: shared hit=30274635 read=664163 dirtied=13 written=3040
         ->  Nested Loop  (cost=2805868.60..3474136.68 rows=132 width=46) (actual time=170327.799..435809.483 rows=3262059 loops=1)
               Buffers: shared hit=30274627 read=664163 dirtied=13 written=3040
               ->  Nested Loop  (cost=2805868.60..3474099.03 rows=132 width=24) (actual time=170326.681..403595.665 rows=3262059 loops=1)
                     Buffers: shared hit=23750509 read=664163 dirtied=13 written=3040
                     ->  Nested Loop  (cost=2805868.60..3473841.00 rows=132 width=24) (actual time=170326.554..250160.219 rows=3262059 loops=1)
                           Buffers: shared hit=10798326 read=550183 written=604
                           ->  Merge Join  (cost=2805868.60..3473802.57 rows=132 width=28) (actual time=170326.513..189542.130 rows=3262059 loops=1)
                                 Merge Cond: ((partsupp.ps_partkey = lineitem.l_partkey) AND (partsupp.ps_suppkey = lineitem.l_suppkey))
                                 Buffers: shared hit=993162 read=550183 written=604
                                 ->  Index Scan using pk_partsupp on partsupp  (cost=0.00..603091.29 rows=8000000 width=12) (actual time=0.026..11010.921 rows=7999985 loops=1)
                                       Buffers: shared hit=348228 read=85981 written=604
                                 ->  Sort  (cost=2805868.46..2814149.41 rows=3312381 width=28) (actual time=170326.362..173386.770 rows=3262059 loops=1)
                                       Sort Key: part.p_partkey, lineitem.l_suppkey
                                       Sort Method: quicksort  Memory: 353153kB
                                       Buffers: shared hit=644934 read=464202
                                       ->  Hash Join  (cost=66898.36..2447146.92 rows=3312381 width=28) (actual time=2478.073..163245.759 rows=3262059 loops=1)
                                             Hash Cond: (lineitem.l_partkey = part.p_partkey)
                                             Buffers: shared hit=644931 read=464202
                                             ->  Seq Scan on lineitem  (cost=0.00..1670262.94 rows=60165494 width=24) (actual time=0.027..43452.158 rows=60045379 loops=1)
                                                   Buffers: shared hit=632494 read=436114
                                             ->  Hash  (cost=65522.00..65522.00 rows=110109 width=4) (actual time=2476.368..2476.368 rows=108576 loops=1)
                                                   Buckets: 16384  Batches: 1  Memory Usage: 3818kB
                                                   Buffers: shared hit=12434 read=28088
                                                   ->  Seq Scan on part  (cost=0.00..65522.00 rows=110109 width=4) (actual time=0.036..2292.533 rows=108576 loops=1)
                                                         Filter: ((p_name)::text ~~ '%tan%'::text)
                                                         Rows Removed by Filter: 1891424
                                                         Buffers: shared hit=12434 read=28088
                           ->  Index Scan using pk_supplier on supplier  (cost=0.00..0.28 rows=1 width=8) (actual time=0.017..0.017 rows=1 loops=3262059)
                                 Index Cond: (s_suppkey = lineitem.l_suppkey)
                                 Buffers: shared hit=9805164
                     ->  Index Only Scan using orders_o_orderkey_o_orderdate_idx on orders  (cost=0.00..1.94 rows=1 width=8) (actual time=0.045..0.046 rows=1 loops=3262059)
                           Index Cond: (o_orderkey = lineitem.l_orderkey)
                           Heap Fetches: 3262059
                           Buffers: shared hit=12952183 read=113980 dirtied=13 written=2436
               ->  Index Scan using pk_nation on nation  (cost=0.00..0.27 rows=1 width=30) (actual time=0.007..0.007 rows=1 loops=3262059)
                     Index Cond: (n_nationkey = supplier.s_nationkey)
                     Buffers: shared hit=6524118
 Total runtime: 461427.732 ms
(44 rows)

COMMIT;
COMMIT