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 '%unusual%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=852156.21..852156.71 rows=200 width=8) (actual time=52337.545..52337.549 rows=45 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=207244 read=83585 written=505
   ->  HashAggregate  (cost=852146.57..852148.57 rows=200 width=8) (actual time=52337.417..52337.429 rows=45 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=207241 read=83585 written=505
         ->  HashAggregate  (cost=814646.57..829646.57 rows=1500000 width=8) (actual time=51148.931..51999.247 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=207241 read=83585 written=505
               ->  Hash Right Join  (cost=69028.00..739425.72 rows=15044169 width=8) (actual time=1285.874..30012.903 rows=15352907 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=207241 read=83585 written=505
                     ->  Seq Scan on orders  (cost=0.00..444735.19 rows=15044169 width=8) (actual time=0.034..9421.004 rows=14852888 loops=1)
                           Filter: ((o_comment)::text !~~ '%unusual%deposits%'::text)
                           Rows Removed by Filter: 162112
                           Buffers: shared hit=174452 read=81096 written=503
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1270.203..1270.203 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=32789 read=2489 written=2
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.028..711.641 rows=1500000 loops=1)
                                 Buffers: shared hit=32789 read=2489 written=2
 Planning time: 4.483 ms
 Execution time: 52365.041 ms
(24 rows)

COMMIT;
COMMIT