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 '1993-05-01'
	and o_orderdate < cast(date '1993-05-01' + 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=2293435.03..2293435.08 rows=20 width=176) (actual time=30723.791..30723.798 rows=20 loops=1)
   Buffers: shared hit=1128864 read=238274 dirtied=321 written=5
   ->  Sort  (cost=2293435.03..2294860.02 rows=569993 width=176) (actual time=30723.789..30723.796 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=1128864 read=238274 dirtied=321 written=5
         ->  HashAggregate  (cost=2272567.80..2278267.73 rows=569993 width=176) (actual time=30374.939..30585.653 rows=381756 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=1128861 read=238274 dirtied=321 written=5
               ->  Hash Join  (cost=346585.76..2258317.97 rows=569993 width=176) (actual time=7269.503..28439.612 rows=1148730 loops=1)
                     Hash Cond: (customer.c_nationkey = nation.n_nationkey)
                     Buffers: shared hit=1128861 read=238274 dirtied=321 written=5
                     ->  Hash Join  (cost=346584.19..2250479.00 rows=569993 width=154) (actual time=7269.470..28043.022 rows=1148730 loops=1)
                           Hash Cond: (orders.o_custkey = customer.c_custkey)
                           Buffers: shared hit=1128860 read=238274 dirtied=321 written=5
                           ->  Hash Join  (cost=277556.19..2172901.11 rows=569993 width=12) (actual time=5957.713..25885.701 rows=1148730 loops=1)
                                 Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
                                 Buffers: shared hit=1093582 read=238274 dirtied=321 written=5
                                 ->  Seq Scan on lineitem  (cost=0.00..1833350.60 rows=15011836 width=12) (actual time=0.012..16431.919 rows=14822772 loops=1)
                                       Filter: (l_returnflag = 'R'::bpchar)
                                       Rows Removed by Filter: 45221404
                                       Buffers: shared hit=887169 read=188875
                                 ->  Hash  (cost=270365.73..270365.73 rows=575237 width=8) (actual time=5954.317..5954.317 rows=574192 loops=1)
                                       Buckets: 1048576  Batches: 1  Memory Usage: 30622kB
                                       Buffers: shared hit=206413 read=49399 dirtied=321 written=5
                                       ->  Bitmap Heap Scan on orders  (cost=5936.18..270365.73 rows=575237 width=8) (actual time=27.771..5755.576 rows=574192 loops=1)
                                             Recheck Cond: ((o_orderdate >= '1993-05-01'::date) AND (o_orderdate < '1993-08-01'::date))
                                             Rows Removed by Index Recheck: 14440808
                                             Heap Blocks: lossy=255801
                                             Buffers: shared hit=206413 read=49399 dirtied=321 written=5
                                             ->  Bitmap Index Scan on orders_o_orderkey_o_orderdate_brin_idx  (cost=0.00..5792.37 rows=575237 width=0) (actual time=27.600..27.600 rows=2558720 loops=1)
                                                   Index Cond: ((o_orderdate >= '1993-05-01'::date) AND (o_orderdate < '1993-08-01'::date))
                                                   Buffers: shared hit=5 read=6
                           ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=146) (actual time=1305.564..1305.564 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..540.364 rows=1500000 loops=1)
                                       Buffers: shared hit=35278
                     ->  Hash  (cost=1.25..1.25 rows=25 width=30) (actual time=0.021..0.021 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..0.007 rows=25 loops=1)
                                 Buffers: shared hit=1
 Planning time: 3.812 ms
 Execution time: 30738.691 ms
(45 rows)

COMMIT;
COMMIT