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=849772.69..849773.19 rows=200 width=8) (actual time=39384.078..39384.081 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=185409 read=104913 written=709
   ->  HashAggregate  (cost=849763.05..849765.05 rows=200 width=8) (actual time=39383.978..39383.991 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=185406 read=104913 written=709
         ->  HashAggregate  (cost=812263.05..827263.05 rows=1500000 width=8) (actual time=38248.239..39047.627 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=185406 read=104913 written=709
               ->  Hash Right Join  (cost=69028.00..737417.50 rows=14969110 width=8) (actual time=1318.197..23535.814 rows=15354690 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=185406 read=104913 written=709
                     ->  Seq Scan on orders  (cost=0.00..443852.85 rows=14969110 width=8) (actual time=0.042..9942.843 rows=14854671 loops=1)
                           Filter: ((o_comment)::text !~~ '%express%deposits%'::text)
                           Rows Removed by Filter: 160329
                           Buffers: shared hit=185404 read=69637 written=689
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1310.134..1310.134 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=2 read=35276 written=20
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.023..859.133 rows=1500000 loops=1)
                                 Buffers: shared hit=2 read=35276 written=20
 Planning time: 3.749 ms
 Execution time: 39408.090 ms
(24 rows)

COMMIT;
COMMIT