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 '%special%deposits%'
		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=928361.43..928361.93 rows=200 width=8) (actual time=60622.633..60622.637 rows=45 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=241701 read=50140 written=45
   ->  HashAggregate  (cost=928351.79..928353.79 rows=200 width=8) (actual time=60622.514..60622.529 rows=45 loops=1)
         Buffers: shared hit=241698 read=50140 written=45
         ->  HashAggregate  (cost=890851.79..905851.79 rows=1500000 width=8) (actual time=59478.730..60302.942 rows=1500000 loops=1)
               Buffers: shared hit=241698 read=50140 written=45
               ->  Hash Right Join  (cost=69028.00..815786.31 rows=15013096 width=8) (actual time=1785.564..43865.114 rows=15352855 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=241698 read=50140 written=45
                     ->  Seq Scan on orders  (cost=0.00..446496.39 rows=15013096 width=8) (actual time=0.040..10631.780 rows=14852837 loops=1)
                           Filter: ((o_comment)::text !~~ '%special%deposits%'::text)
                           Rows Removed by Filter: 162163
                           Buffers: shared hit=241696 read=14864 written=45
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1783.534..1783.534 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=2 read=35276
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.011..1082.717 rows=1500000 loops=1)
                                 Buffers: shared hit=2 read=35276
 Total runtime: 60655.725 ms
(21 rows)

COMMIT;
COMMIT