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 '%express%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=845029.86..845030.36 rows=200 width=8) (actual time=31101.928..31101.931 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=165319 read=123990 dirtied=191 written=1779
   ->  HashAggregate  (cost=845020.22..845022.22 rows=200 width=8) (actual time=31101.831..31101.842 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=165316 read=123990 dirtied=191 written=1779
         ->  HashAggregate  (cost=807520.22..822520.22 rows=1500000 width=8) (actual time=30254.087..30774.535 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=165316 read=123990 dirtied=191 written=1779
               ->  Hash Right Join  (cost=69028.00..733419.64 rows=14820116 width=8) (actual time=1226.438..20104.307 rows=15339884 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=165316 read=123990 dirtied=191 written=1779
                     ->  Seq Scan on orders  (cost=0.00..442089.90 rows=14820116 width=8) (actual time=0.028..8971.885 rows=14839865 loops=1)
                           Filter: ((o_comment)::text !~~ '%express%deposits%'::text)
                           Rows Removed by Filter: 160135
                           Buffers: shared hit=165313 read=88715 dirtied=191 written=523
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1214.803..1214.803 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=3 read=35275 written=1256
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.012..764.650 rows=1500000 loops=1)
                                 Buffers: shared hit=3 read=35275 written=1256
 Planning time: 3.301 ms
 Execution time: 31125.384 ms
(24 rows)

COMMIT;
COMMIT