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 '1993-07-01'
	and o_orderdate < cast(date '1993-07-01' + 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=2283089.69..2283089.74 rows=20 width=176) (actual time=31396.779..31396.784 rows=20 loops=1)
   Buffers: shared hit=707183 read=653381 dirtied=750 written=774
   ->  Sort  (cost=2283089.69..2284519.04 rows=571739 width=176) (actual time=31396.776..31396.780 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=707183 read=653381 dirtied=750 written=774
         ->  HashAggregate  (cost=2262158.53..2267875.92 rows=571739 width=176) (actual time=31019.762..31259.190 rows=381883 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=707180 read=653381 dirtied=750 written=774
               ->  Hash Join  (cost=345384.82..2247865.06 rows=571739 width=176) (actual time=6876.488..28978.885 rows=1148292 loops=1)
                     Hash Cond: (customer.c_nationkey = nation.n_nationkey)
                     Buffers: shared hit=707180 read=653381 dirtied=750 written=774
                     ->  Hash Join  (cost=345383.26..2240002.08 rows=571739 width=154) (actual time=6876.459..28569.053 rows=1148292 loops=1)
                           Hash Cond: (orders.o_custkey = customer.c_custkey)
                           Buffers: shared hit=707179 read=653381 dirtied=750 written=774
                           ->  Hash Join  (cost=276355.26..2162398.00 rows=571739 width=12) (actual time=5541.844..26504.379 rows=1148292 loops=1)
                                 Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
                                 Buffers: shared hit=671901 read=653381 dirtied=750 written=774
                                 ->  Seq Scan on lineitem  (cost=0.00..1824308.60 rows=14937799 width=12) (actual time=0.047..17621.379 rows=14823489 loops=1)
                                       Filter: (l_returnflag = 'R'::bpchar)
                                       Rows Removed by Filter: 45222732
                                       Buffers: shared hit=436138 read=634599 dirtied=750 written=734
                                 ->  Hash  (cost=269142.92..269142.92 rows=576987 width=8) (actual time=5538.287..5538.287 rows=574316 loops=1)
                                       Buckets: 1048576  Batches: 1  Memory Usage: 30627kB
                                       Buffers: shared hit=235763 read=18782 written=40
                                       ->  Bitmap Heap Scan on orders  (cost=5954.12..269142.92 rows=576987 width=8) (actual time=27.449..5327.335 rows=574316 loops=1)
                                             Recheck Cond: ((o_orderdate >= '1993-07-01'::date) AND (o_orderdate < '1993-10-01'::date))
                                             Rows Removed by Index Recheck: 14440684
                                             Heap Blocks: lossy=254534
                                             Buffers: shared hit=235763 read=18782 written=40
                                             ->  Bitmap Index Scan on orders_o_orderkey_o_orderdate_brin_idx  (cost=0.00..5809.87 rows=576987 width=0) (actual time=27.265..27.265 rows=2545920 loops=1)
                                                   Index Cond: ((o_orderdate >= '1993-07-01'::date) AND (o_orderdate < '1993-10-01'::date))
                                                   Buffers: shared hit=11
                           ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=146) (actual time=1328.471..1328.471 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..546.494 rows=1500000 loops=1)
                                       Buffers: shared hit=35278
                     ->  Hash  (cost=1.25..1.25 rows=25 width=30) (actual time=0.018..0.018 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: 3.911 ms
 Execution time: 31411.190 ms
(45 rows)

COMMIT;
COMMIT