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 '1993-11-01'
	and o_orderdate < cast(date '1993-11-01' + 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=2289791.97..2289792.02 rows=20 width=176) (actual time=32187.762..32187.769 rows=20 loops=1)
   Buffers: shared hit=877934 read=487880 dirtied=4 written=39
   ->  Sort  (cost=2289791.97..2291189.69 rows=559091 width=176) (actual time=32187.759..32187.765 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=877934 read=487880 dirtied=4 written=39
         ->  HashAggregate  (cost=2269323.85..2274914.76 rows=559091 width=176) (actual time=31834.661..32043.399 rows=381592 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=877931 read=487880 dirtied=4 written=39
               ->  Hash Join  (cost=345917.59..2255346.57 rows=559091 width=176) (actual time=7689.757..29807.950 rows=1148303 loops=1)
                     Hash Cond: (customer.c_nationkey = nation.n_nationkey)
                     Buffers: shared hit=877931 read=487880 dirtied=4 written=39
                     ->  Hash Join  (cost=345916.03..2247657.51 rows=559091 width=154) (actual time=7689.724..29395.459 rows=1148303 loops=1)
                           Hash Cond: (orders.o_custkey = customer.c_custkey)
                           Buffers: shared hit=877930 read=487880 dirtied=4 written=39
                           ->  Hash Join  (cost=276888.03..2170243.14 rows=559091 width=12) (actual time=5975.215..26843.137 rows=1148303 loops=1)
                                 Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
                                 Buffers: shared hit=877928 read=452604 dirtied=4 written=10
                                 ->  Seq Scan on lineitem  (cost=0.00..1831525.85 rows=14996895 width=12) (actual time=0.037..17702.971 rows=14822845 loops=1)
                                       Filter: (l_returnflag = 'R'::bpchar)
                                       Rows Removed by Filter: 45221237
                                       Buffers: shared hit=671443 read=403530 dirtied=2 written=3
                                 ->  Hash  (cost=269835.04..269835.04 rows=564239 width=8) (actual time=5969.922..5969.922 rows=574194 loops=1)
                                       Buckets: 1048576  Batches: 1  Memory Usage: 30622kB
                                       Buffers: shared hit=206485 read=49074 dirtied=2 written=7
                                       ->  Bitmap Heap Scan on orders  (cost=5823.45..269835.04 rows=564239 width=8) (actual time=27.640..5762.027 rows=574194 loops=1)
                                             Recheck Cond: ((o_orderdate >= '1993-11-01'::date) AND (o_orderdate < '1994-02-01'::date))
                                             Rows Removed by Index Recheck: 14440806
                                             Heap Blocks: lossy=255548
                                             Buffers: shared hit=206485 read=49074 dirtied=2 written=7
                                             ->  Bitmap Index Scan on orders_o_orderkey_o_orderdate_brin_idx  (cost=0.00..5682.39 rows=564239 width=0) (actual time=27.455..27.455 rows=2556160 loops=1)
                                                   Index Cond: ((o_orderdate >= '1993-11-01'::date) AND (o_orderdate < '1994-02-01'::date))
                                                   Buffers: shared hit=3 read=8
                           ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=146) (actual time=1700.907..1700.907 rows=1500000 loops=1)
                                 Buckets: 2097152  Batches: 1  Memory Usage: 281501kB
                                 Buffers: shared hit=2 read=35276 written=29
                                 ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=146) (actual time=0.011..840.964 rows=1500000 loops=1)
                                       Buffers: shared hit=2 read=35276 written=29
                     ->  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..0.007 rows=25 loops=1)
                                 Buffers: shared hit=1
 Planning time: 4.590 ms
 Execution time: 32201.546 ms
(45 rows)

COMMIT;
COMMIT