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 '1994-10-01'
	and o_orderdate < cast(date '1994-10-01' + 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=2295102.34..2295102.39 rows=20 width=176) (actual time=31541.614..31541.620 rows=20 loops=1)
   Buffers: shared hit=933647 read=433491 dirtied=1 written=1716
   ->  Sort  (cost=2295102.34..2296557.43 rows=582035 width=176) (actual time=31541.611..31541.613 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=933647 read=433491 dirtied=1 written=1716
         ->  HashAggregate  (cost=2273794.25..2279614.60 rows=582035 width=176) (actual time=31160.091..31403.484 rows=381798 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=933644 read=433491 dirtied=1 written=1716
               ->  Hash Join  (cost=347044.53..2259243.38 rows=582035 width=176) (actual time=7589.688..29187.811 rows=1150166 loops=1)
                     Hash Cond: (customer.c_nationkey = nation.n_nationkey)
                     Buffers: shared hit=933644 read=433491 dirtied=1 written=1716
                     ->  Hash Join  (cost=347042.97..2251238.83 rows=582035 width=154) (actual time=7589.658..28790.014 rows=1150166 loops=1)
                           Hash Cond: (orders.o_custkey = customer.c_custkey)
                           Buffers: shared hit=933643 read=433491 dirtied=1 written=1716
                           ->  Hash Join  (cost=278014.97..2173480.31 rows=582035 width=12) (actual time=6249.432..26615.655 rows=1150166 loops=1)
                                 Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
                                 Buffers: shared hit=898365 read=433491 dirtied=1 written=1716
                                 ->  Seq Scan on lineitem  (cost=0.00..1833350.60 rows=15011836 width=12) (actual time=0.041..16915.803 rows=14808082 loops=1)
                                       Filter: (l_returnflag = 'R'::bpchar)
                                       Rows Removed by Filter: 45176302
                                       Buffers: shared hit=726258 read=349786 dirtied=1 written=1
                                 ->  Hash  (cost=270672.60..270672.60 rows=587390 width=8) (actual time=6244.537..6244.537 rows=574321 loops=1)
                                       Buckets: 1048576  Batches: 1  Memory Usage: 30627kB
                                       Buffers: shared hit=172107 read=83705 written=1715
                                       ->  Bitmap Heap Scan on orders  (cost=6060.75..270672.60 rows=587390 width=8) (actual time=27.655..6025.540 rows=574321 loops=1)
                                             Recheck Cond: ((o_orderdate >= '1994-10-01'::date) AND (o_orderdate < '1995-01-01'::date))
                                             Rows Removed by Index Recheck: 14425679
                                             Heap Blocks: lossy=255801
                                             Buffers: shared hit=172107 read=83705 written=1715
                                             ->  Bitmap Index Scan on orders_o_orderkey_o_orderdate_brin_idx  (cost=0.00..5913.90 rows=587390 width=0) (actual time=27.472..27.472 rows=2558720 loops=1)
                                                   Index Cond: ((o_orderdate >= '1994-10-01'::date) AND (o_orderdate < '1995-01-01'::date))
                                                   Buffers: shared hit=3 read=8
                           ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=146) (actual time=1330.062..1330.062 rows=1500000 loops=1)
                                 Buckets: 2097152  Batches: 1  Memory Usage: 281501kB
                                 Buffers: shared hit=35278
                                 ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=146) (actual time=0.008..543.937 rows=1500000 loops=1)
                                       Buffers: shared hit=35278
                     ->  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=0.004..0.009 rows=25 loops=1)
                                 Buffers: shared hit=1
 Planning time: 3.854 ms
 Execution time: 31558.919 ms
(45 rows)

COMMIT;
COMMIT