BEGIN;
BEGIN
EXPLAIN (ANALYZE, BUFFERS)
select
	c_custkey,
	c_name,
	sum(l_extendedprice * (1 - l_discount)) as revenue,
	c_acctbal,
	n_name,
	c_address,
	c_phone,
	c_comment
from
	customer,
	orders,
	lineitem,
	nation
where
	c_custkey = o_custkey
	and l_orderkey = o_orderkey
	and o_orderdate >= date '1993-02-01'
	and o_orderdate < cast(date '1993-02-01' + interval '3 month' as date)
	and l_returnflag = 'R'
	and c_nationkey = n_nationkey
group by
	c_custkey,
	c_name,
	c_acctbal,
	c_phone,
	n_name,
	c_address,
	c_comment
order by
	revenue desc
LIMIT 20;
                                                                                               QUERY PLAN                                                                                                
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=2271885.22..2271885.27 rows=20 width=176) (actual time=35167.056..35167.062 rows=20 loops=1)
   Buffers: shared hit=758123 read=597165
   ->  Sort  (cost=2271885.22..2273265.74 rows=552205 width=176) (actual time=35167.053..35167.058 rows=20 loops=1)
         Sort Key: (sum((lineitem.l_extendedprice * (1::double precision - lineitem.l_discount))))
         Sort Method: top-N heapsort  Memory: 30kB
         Buffers: shared hit=758123 read=597165
         ->  HashAggregate  (cost=2251669.20..2257191.25 rows=552205 width=176) (actual time=34843.148..35030.748 rows=373018 loops=1)
               Group Key: customer.c_custkey, customer.c_name, customer.c_acctbal, customer.c_phone, nation.n_name, customer.c_address, customer.c_comment
               Buffers: shared hit=758120 read=597165
               ->  Hash Join  (cost=343628.81..2237864.07 rows=552205 width=176) (actual time=11215.627..33067.968 rows=1113984 loops=1)
                     Hash Cond: (customer.c_nationkey = nation.n_nationkey)
                     Buffers: shared hit=758120 read=597165
                     ->  Hash Join  (cost=343627.25..2230269.69 rows=552205 width=154) (actual time=11215.598..32674.132 rows=1113984 loops=1)
                           Hash Cond: (orders.o_custkey = customer.c_custkey)
                           Buffers: shared hit=758119 read=597165
                           ->  Hash Join  (cost=274599.25..2152958.62 rows=552205 width=12) (actual time=9600.092..30306.140 rows=1113984 loops=1)
                                 Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
                                 Buffers: shared hit=758117 read=561889
                                 ->  Seq Scan on lineitem  (cost=0.00..1817043.65 rows=14878312 width=12) (actual time=0.013..17473.899 rows=14822992 loops=1)
                                       Filter: (l_returnflag = 'R'::bpchar)
                                       Rows Removed by Filter: 45222677
                                       Buffers: shared hit=758113 read=308360
                                 ->  Hash  (cost=267633.27..267633.27 rows=557278 width=8) (actual time=9595.877..9595.877 rows=555666 loops=1)
                                       Buckets: 1048576  Batches: 1  Memory Usage: 29898kB
                                       Buffers: shared hit=4 read=253529
                                       ->  Bitmap Heap Scan on orders  (cost=5752.10..267633.27 rows=557278 width=8) (actual time=27.795..9302.676 rows=555666 loops=1)
                                             Recheck Cond: ((o_orderdate >= '1993-02-01'::date) AND (o_orderdate < '1993-05-01'::date))
                                             Rows Removed by Index Recheck: 14459334
                                             Heap Blocks: lossy=253522
                                             Buffers: shared hit=4 read=253529
                                             ->  Bitmap Index Scan on orders_o_orderkey_o_orderdate_brin_idx  (cost=0.00..5612.78 rows=557278 width=0) (actual time=27.514..27.514 rows=2535680 loops=1)
                                                   Index Cond: ((o_orderdate >= '1993-02-01'::date) AND (o_orderdate < '1993-05-01'::date))
                                                   Buffers: shared hit=2 read=9
                           ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=146) (actual time=1609.444..1609.444 rows=1500000 loops=1)
                                 Buckets: 2097152  Batches: 1  Memory Usage: 281501kB
                                 Buffers: shared hit=2 read=35276
                                 ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=146) (actual time=0.003..813.553 rows=1500000 loops=1)
                                       Buffers: shared hit=2 read=35276
                     ->  Hash  (cost=1.25..1.25 rows=25 width=30) (actual time=0.020..0.020 rows=25 loops=1)
                           Buckets: 1024  Batches: 1  Memory Usage: 10kB
                           Buffers: shared hit=1
                           ->  Seq Scan on nation  (cost=0.00..1.25 rows=25 width=30) (actual time=0.005..0.010 rows=25 loops=1)
                                 Buffers: shared hit=1
 Planning time: 4.145 ms
 Execution time: 35175.139 ms
(45 rows)

COMMIT;
COMMIT