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=852120.87..852121.37 rows=200 width=8) (actual time=30524.514..30524.516 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=178339 read=112996 dirtied=119 written=744
   ->  HashAggregate  (cost=852111.23..852113.23 rows=200 width=8) (actual time=30524.384..30524.393 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=178336 read=112996 dirtied=119 written=744
         ->  HashAggregate  (cost=814611.23..829611.23 rows=1500000 width=8) (actual time=29760.301..30206.369 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=178336 read=112996 dirtied=119 written=744
               ->  Hash Right Join  (cost=69028.00..739619.37 rows=14998372 width=8) (actual time=1520.672..20304.865 rows=15353127 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=178336 read=112996 dirtied=119 written=744
                     ->  Seq Scan on orders  (cost=0.00..445615.79 rows=14998372 width=8) (actual time=0.030..8961.285 rows=14853111 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%accounts%'::text)
                           Rows Removed by Filter: 161889
                           Buffers: shared hit=178334 read=77720 dirtied=119 written=663
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1507.034..1507.034 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=2 read=35276 written=81
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.025..1006.856 rows=1500000 loops=1)
                                 Buffers: shared hit=2 read=35276 written=81
 Planning time: 5.478 ms
 Execution time: 30552.330 ms
(24 rows)

COMMIT;
COMMIT