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=852894.39..852894.89 rows=200 width=8) (actual time=47759.130..47759.133 rows=45 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=222989 read=68093 written=463
   ->  HashAggregate  (cost=852884.75..852886.75 rows=200 width=8) (actual time=47758.996..47759.011 rows=45 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=222986 read=68093 written=463
         ->  HashAggregate  (cost=815384.75..830384.75 rows=1500000 width=8) (actual time=46562.769..47418.069 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=222986 read=68093 written=463
               ->  Hash Right Join  (cost=69028.00..740089.43 rows=15059063 width=8) (actual time=1383.277..29996.749 rows=15352894 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=222986 read=68093 written=463
                     ->  Seq Scan on orders  (cost=0.00..445175.49 rows=15059063 width=8) (actual time=0.026..9136.222 rows=14852875 loops=1)
                           Filter: ((o_comment)::text !~~ '%unusual%deposits%'::text)
                           Rows Removed by Filter: 162125
                           Buffers: shared hit=187816 read=67985 written=463
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1363.321..1363.321 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=35170 read=108
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.023..737.464 rows=1500000 loops=1)
                                 Buffers: shared hit=35170 read=108
 Planning time: 4.159 ms
 Execution time: 47790.513 ms
(24 rows)

COMMIT;
COMMIT