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=852427.39..852427.89 rows=200 width=8) (actual time=35392.198..35392.203 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=208673 read=82662 written=591
   ->  HashAggregate  (cost=852417.75..852419.75 rows=200 width=8) (actual time=35392.104..35392.115 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=208670 read=82662 written=591
         ->  HashAggregate  (cost=814917.75..829917.75 rows=1500000 width=8) (actual time=34163.773..35062.316 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=208670 read=82662 written=591
               ->  Hash Right Join  (cost=69028.00..739849.26 rows=15013698 width=8) (actual time=1145.170..21172.529 rows=15338066 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=208670 read=82662 written=591
                     ->  Seq Scan on orders  (cost=0.00..445615.79 rows=15013698 width=8) (actual time=0.026..8360.395 rows=14838047 loops=1)
                           Filter: ((o_comment)::text !~~ '%unusual%deposits%'::text)
                           Rows Removed by Filter: 161953
                           Buffers: shared hit=198688 read=57366 written=543
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1132.874..1132.874 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=9982 read=25296 written=48
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.016..689.742 rows=1500000 loops=1)
                                 Buffers: shared hit=9982 read=25296 written=48
 Planning time: 3.084 ms
 Execution time: 35419.916 ms
(24 rows)

COMMIT;
COMMIT