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=926362.56..926363.06 rows=200 width=8) (actual time=65417.755..65417.757 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=271542 read=19793 written=13
   ->  HashAggregate  (cost=926352.91..926354.91 rows=200 width=8) (actual time=65417.639..65417.646 rows=46 loops=1)
         Buffers: shared hit=271539 read=19793 written=13
         ->  HashAggregate  (cost=888852.91..903852.91 rows=1500000 width=8) (actual time=64294.665..65097.566 rows=1500000 loops=1)
               Buffers: shared hit=271539 read=19793 written=13
               ->  Hash Right Join  (cost=69028.00..814011.09 rows=14968365 width=8) (actual time=1394.761..45967.268 rows=15353127 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=271539 read=19793 written=13
                     ->  Seq Scan on orders  (cost=0.00..445615.79 rows=14968365 width=8) (actual time=0.050..10021.787 rows=14853111 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%accounts%'::text)
                           Rows Removed by Filter: 161889
                           Buffers: shared hit=237134 read=18920 written=13
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1392.459..1392.459 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=34405 read=873
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.016..707.593 rows=1500000 loops=1)
                                 Buffers: shared hit=34405 read=873
 Total runtime: 65458.052 ms
(21 rows)

COMMIT;
COMMIT