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=849751.39..849751.89 rows=200 width=8) (actual time=36734.419..36734.422 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=177369 read=113460 written=619
   ->  HashAggregate  (cost=849741.75..849743.75 rows=200 width=8) (actual time=36734.318..36734.326 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=177366 read=113460 written=619
         ->  HashAggregate  (cost=812241.75..827241.75 rows=1500000 width=8) (actual time=35813.194..36408.890 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=177366 read=113460 written=619
               ->  Hash Right Join  (cost=69028.00..737622.11 rows=14923928 width=8) (actual time=1315.552..22404.614 rows=15339813 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=177366 read=113460 written=619
                     ->  Seq Scan on orders  (cost=0.00..444735.19 rows=14923928 width=8) (actual time=0.029..8963.055 rows=14839795 loops=1)
                           Filter: ((o_comment)::text !~~ '%express%deposits%'::text)
                           Rows Removed by Filter: 160205
                           Buffers: shared hit=172277 read=83271 written=521
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1302.578..1302.578 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=5089 read=30189 written=98
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.011..776.846 rows=1500000 loops=1)
                                 Buffers: shared hit=5089 read=30189 written=98
 Planning time: 3.131 ms
 Execution time: 36757.701 ms
(24 rows)

COMMIT;
COMMIT