BEGIN;
BEGIN
EXPLAIN (ANALYZE, BUFFERS)
select
	c_count,
	count(*) as custdist
from
	(
		select
			c_custkey,
			count(o_orderkey)
		from
			customer left outer join orders on
				c_custkey = o_custkey
				and o_comment not like '%pending%accounts%'
		group by
			c_custkey
	) as c_orders (c_custkey, c_count)
group by
	c_count
order by
	custdist desc,
	c_count desc;
                                                                    QUERY PLAN                                                                     
---------------------------------------------------------------------------------------------------------------------------------------------------
 Sort  (cost=851384.17..851384.67 rows=200 width=8) (actual time=47938.504..47938.507 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=156973 read=134109 written=437
   ->  HashAggregate  (cost=851374.53..851376.53 rows=200 width=8) (actual time=47938.377..47938.389 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=156970 read=134109 written=437
         ->  HashAggregate  (cost=813874.53..828874.53 rows=1500000 width=8) (actual time=46996.401..47598.214 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=156970 read=134109 written=437
               ->  Hash Right Join  (cost=69028.00..738956.77 rows=14983552 width=8) (actual time=2737.487..30018.763 rows=15338278 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=156970 read=134109 written=437
                     ->  Seq Scan on orders  (cost=0.00..445175.49 rows=14983552 width=8) (actual time=0.034..9249.684 rows=14838262 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%accounts%'::text)
                           Rows Removed by Filter: 161738
                           Buffers: shared hit=150014 read=105787 written=386
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1625.483..1625.483 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=6956 read=28322 written=51
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.029..1035.132 rows=1500000 loops=1)
                                 Buffers: shared hit=6956 read=28322 written=51
 Planning time: 4.461 ms
 Execution time: 47973.112 ms
(24 rows)

COMMIT;
COMMIT