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=927931.83..927932.33 rows=200 width=8) (actual time=71006.809..71006.812 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=280737 read=10851 written=134
   ->  HashAggregate  (cost=927922.19..927924.19 rows=200 width=8) (actual time=71006.701..71006.712 rows=46 loops=1)
         Buffers: shared hit=280734 read=10851 written=134
         ->  HashAggregate  (cost=890422.19..905422.19 rows=1500000 width=8) (actual time=69933.367..70668.805 rows=1500000 loops=1)
               Buffers: shared hit=280734 read=10851 written=134
               ->  Hash Right Join  (cost=69028.00..815354.57 rows=15013524 width=8) (actual time=2158.024..50629.112 rows=15353131 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=280734 read=10851 written=134
                     ->  Seq Scan on orders  (cost=0.00..446056.09 rows=15013524 width=8) (actual time=0.045..13054.698 rows=14853115 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%accounts%'::text)
                           Rows Removed by Filter: 161885
                           Buffers: shared hit=251192 read=5115 written=134
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=2156.302..2156.302 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=29542 read=5736
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.012..1245.096 rows=1500000 loops=1)
                                 Buffers: shared hit=29542 read=5736
 Total runtime: 71039.242 ms
(21 rows)

COMMIT;
COMMIT