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 '1993-03-01'
	and o_orderdate < cast(date '1993-03-01' + 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=2298149.71..2298149.76 rows=20 width=176) (actual time=31767.477..31767.484 rows=20 loops=1)
   Buffers: shared hit=976527 read=393259 dirtied=788 written=374
   ->  Sort  (cost=2298149.71..2299582.77 rows=573224 width=176) (actual time=31767.473..31767.477 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=976527 read=393259 dirtied=788 written=374
         ->  HashAggregate  (cost=2277164.19..2282896.43 rows=573224 width=176) (actual time=31431.912..31630.040 rows=382262 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=976524 read=393259 dirtied=788 written=374
               ->  Hash Join  (cost=347214.60..2262833.59 rows=573224 width=176) (actual time=8135.828..29479.168 rows=1149422 loops=1)
                     Hash Cond: (customer.c_nationkey = nation.n_nationkey)
                     Buffers: shared hit=976524 read=393259 dirtied=788 written=374
                     ->  Hash Join  (cost=347213.04..2254950.20 rows=573224 width=154) (actual time=8135.799..29079.883 rows=1149422 loops=1)
                           Hash Cond: (orders.o_custkey = customer.c_custkey)
                           Buffers: shared hit=976523 read=393259 dirtied=788 written=374
                           ->  Hash Join  (cost=278185.04..2177323.84 rows=573224 width=12) (actual time=6599.145..26732.406 rows=1149422 loops=1)
                                 Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
                                 Buffers: shared hit=941358 read=393146 dirtied=788 written=374
                                 ->  Seq Scan on lineitem  (cost=0.00..1837000.11 rows=15041719 width=12) (actual time=0.040..17016.257 rows=14822519 loops=1)
                                       Filter: (l_returnflag = 'R'::bpchar)
                                       Rows Removed by Filter: 45222475
                                       Buffers: shared hit=769086 read=309100 dirtied=535
                                 ->  Hash  (cost=270953.90..270953.90 rows=578491 width=8) (actual time=6594.093..6594.093 rows=574015 loops=1)
                                       Buckets: 1048576  Batches: 1  Memory Usage: 30615kB
                                       Buffers: shared hit=172272 read=84046 dirtied=253 written=374
                                       ->  Bitmap Heap Scan on orders  (cost=5969.53..270953.90 rows=578491 width=8) (actual time=30.740..6373.933 rows=574015 loops=1)
                                             Recheck Cond: ((o_orderdate >= '1993-03-01'::date) AND (o_orderdate < '1993-06-01'::date))
                                             Rows Removed by Index Recheck: 14440985
                                             Heap Blocks: lossy=256307
                                             Buffers: shared hit=172272 read=84046 dirtied=253 written=374
                                             ->  Bitmap Index Scan on orders_o_orderkey_o_orderdate_brin_idx  (cost=0.00..5824.91 rows=578491 width=0) (actual time=30.568..30.568 rows=2563840 loops=1)
                                                   Index Cond: ((o_orderdate >= '1993-03-01'::date) AND (o_orderdate < '1993-06-01'::date))
                                                   Buffers: shared hit=2 read=9
                           ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=146) (actual time=1527.820..1527.820 rows=1500000 loops=1)
                                 Buckets: 2097152  Batches: 1  Memory Usage: 281501kB
                                 Buffers: shared hit=35165 read=113
                                 ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=146) (actual time=0.008..607.989 rows=1500000 loops=1)
                                       Buffers: shared hit=35165 read=113
                     ->  Hash  (cost=1.25..1.25 rows=25 width=30) (actual time=0.019..0.019 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..0.008 rows=25 loops=1)
                                 Buffers: shared hit=1
 Planning time: 4.113 ms
 Execution time: 31779.243 ms
(45 rows)

COMMIT;
COMMIT