BEGIN;
BEGIN
EXPLAIN (ANALYZE, BUFFERS)
select
	n_name,
	sum(l_extendedprice * (1 - l_discount)) as revenue
from
	customer,
	orders,
	lineitem,
	supplier,
	nation,
	region
where
	c_custkey = o_custkey
	and l_orderkey = o_orderkey
	and l_suppkey = s_suppkey
	and c_nationkey = s_nationkey
	and s_nationkey = n_nationkey
	and n_regionkey = r_regionkey
	and r_name = 'AFRICA'
	and o_orderdate >= date '1996-01-01'
	and o_orderdate < date '1996-01-01' + interval '1 year'
group by
	n_name
order by
	revenue desc;
                                                                                              QUERY PLAN                                                                                               
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Sort  (cost=2433636.74..2433636.80 rows=25 width=34) (actual time=79446.069..79446.069 rows=5 loops=1)
   Sort Key: (sum((lineitem.l_extendedprice * (1::double precision - lineitem.l_discount))))
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=927521 read=553695
   ->  HashAggregate  (cost=2433635.91..2433636.16 rows=25 width=34) (actual time=79445.997..79446.003 rows=5 loops=1)
         Buffers: shared hit=927518 read=553695
         ->  Hash Join  (cost=400363.93..2432904.89 rows=73102 width=34) (actual time=12075.770..79283.699 rows=72666 loops=1)
               Hash Cond: ((lineitem.l_suppkey = supplier.s_suppkey) AND (customer.c_nationkey = supplier.s_nationkey))
               Buffers: shared hit=927518 read=553695
               ->  Hash Join  (cost=395684.93..2390944.11 rows=1827538 width=46) (actual time=11944.492..75148.216 rows=1827544 loops=1)
                     Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
                     Buffers: shared hit=925336 read=553695
                     ->  Seq Scan on lineitem  (cost=0.00..1675255.19 rows=60345719 width=16) (actual time=0.026..19482.803 rows=60045826 loops=1)
                           Buffers: shared hit=540994 read=530804
                     ->  Hash  (cost=389972.56..389972.56 rows=456990 width=38) (actual time=11943.884..11943.884 rows=456567 loops=1)
                           Buckets: 65536  Batches: 1  Memory Usage: 32103kB
                           Buffers: shared hit=384342 read=22891
                           ->  Hash Join  (cost=87772.87..389972.56 rows=456990 width=38) (actual time=3005.420..11673.348 rows=456567 loops=1)
                                 Hash Cond: (orders.o_custkey = customer.c_custkey)
                                 Buffers: shared hit=384342 read=22891
                                 ->  Bitmap Heap Scan on orders  (cost=48730.65..337791.88 rows=2284949 width=8) (actual time=940.475..3764.212 rows=2283972 loops=1)
                                       Recheck Cond: ((o_orderdate >= '1996-01-01'::date) AND (o_orderdate < '1997-01-01 00:00:00'::timestamp without time zone))
                                       Buffers: shared hit=247030 read=14053
                                       ->  Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx  (cost=0.00..48159.41 rows=2284949 width=0) (actual time=773.049..773.049 rows=2295345 loops=1)
                                             Index Cond: ((o_orderdate >= '1996-01-01'::date) AND (o_orderdate < '1997-01-01 00:00:00'::timestamp without time zone))
                                             Buffers: shared hit=2 read=6311
                                 ->  Hash  (cost=35292.22..35292.22 rows=300000 width=38) (actual time=2063.964..2063.964 rows=299493 loops=1)
                                       Buckets: 32768  Batches: 1  Memory Usage: 21059kB
                                       Buffers: shared hit=137312 read=8838
                                       ->  Nested Loop  (cost=905.09..35292.22 rows=300000 width=38) (actual time=34.972..1166.626 rows=299493 loops=1)
                                             Buffers: shared hit=137312 read=8838
                                             ->  Nested Loop  (cost=0.00..14.07 rows=5 width=30) (actual time=0.077..0.184 rows=5 loops=1)
                                                   Join Filter: (nation.n_regionkey = region.r_regionkey)
                                                   Rows Removed by Join Filter: 20
                                                   Buffers: shared hit=3
                                                   ->  Index Scan using pk_nation on nation  (cost=0.00..12.63 rows=25 width=34) (actual time=0.035..0.073 rows=25 loops=1)
                                                         Buffers: shared hit=2
                                                   ->  Materialize  (cost=0.00..1.07 rows=1 width=4) (actual time=0.002..0.003 rows=1 loops=25)
                                                         Buffers: shared hit=1
                                                         ->  Seq Scan on region  (cost=0.00..1.06 rows=1 width=4) (actual time=0.025..0.034 rows=1 loops=1)
                                                               Filter: (r_name = 'AFRICA'::bpchar)
                                                               Rows Removed by Filter: 4
                                                               Buffers: shared hit=1
                                             ->  Bitmap Heap Scan on customer  (cost=905.09..6455.63 rows=60000 width=8) (actual time=27.263..212.088 rows=59899 loops=5)
                                                   Recheck Cond: (c_nationkey = nation.n_nationkey)
                                                   Buffers: shared hit=137309 read=8838
                                                   ->  Bitmap Index Scan on customer_c_nationkey_c_custkey_idx  (cost=0.00..890.09 rows=60000 width=0) (actual time=16.667..16.667 rows=59899 loops=5)
                                                         Index Cond: (c_nationkey = nation.n_nationkey)
                                                         Buffers: shared hit=10 read=823
               ->  Hash  (cost=3179.00..3179.00 rows=100000 width=8) (actual time=130.032..130.032 rows=100000 loops=1)
                     Buckets: 16384  Batches: 1  Memory Usage: 3907kB
                     Buffers: shared hit=2179
                     ->  Seq Scan on supplier  (cost=0.00..3179.00 rows=100000 width=8) (actual time=0.010..96.377 rows=100000 loops=1)
                           Buffers: shared hit=2179
 Total runtime: 79478.202 ms
(55 rows)

COMMIT;
COMMIT