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=851690.39..851690.89 rows=200 width=8) (actual time=29274.266..29274.270 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=196003 read=95079 written=1317
   ->  HashAggregate  (cost=851680.75..851682.75 rows=200 width=8) (actual time=29274.155..29274.165 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=196000 read=95079 written=1317
         ->  HashAggregate  (cost=814180.75..829180.75 rows=1500000 width=8) (actual time=28449.638..28956.714 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=196000 read=95079 written=1317
               ->  Hash Right Join  (cost=69028.00..739186.43 rows=14998863 width=8) (actual time=1199.432..18597.799 rows=15338061 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=196000 read=95079 written=1317
                     ->  Seq Scan on orders  (cost=0.00..445175.49 rows=14998863 width=8) (actual time=0.033..8224.439 rows=14838042 loops=1)
                           Filter: ((o_comment)::text !~~ '%unusual%deposits%'::text)
                           Rows Removed by Filter: 161958
                           Buffers: shared hit=195998 read=59803 written=1127
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1188.476..1188.476 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=2 read=35276 written=190
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.009..758.601 rows=1500000 loops=1)
                                 Buffers: shared hit=2 read=35276 written=190
 Planning time: 3.400 ms
 Execution time: 29635.010 ms
(24 rows)

COMMIT;
COMMIT