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=923982.93..923983.43 rows=200 width=8) (actual time=75642.860..75642.864 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=247068 read=43761 written=1
   ->  HashAggregate  (cost=923973.29..923975.29 rows=200 width=8) (actual time=75642.733..75642.746 rows=46 loops=1)
         Buffers: shared hit=247065 read=43761 written=1
         ->  HashAggregate  (cost=886473.29..901473.29 rows=1500000 width=8) (actual time=74383.094..75303.676 rows=1500000 loops=1)
               Buffers: shared hit=247065 read=43761 written=1
               ->  Hash Right Join  (cost=69028.00..811931.27 rows=14908404 width=8) (actual time=3362.428..55061.613 rows=15354647 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=247065 read=43761 written=1
                     ->  Seq Scan on orders  (cost=0.00..444735.19 rows=14908404 width=8) (actual time=0.042..15398.695 rows=14854629 loops=1)
                           Filter: ((o_comment)::text !~~ '%express%deposits%'::text)
                           Rows Removed by Filter: 160371
                           Buffers: shared hit=247062 read=8486 written=1
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=3360.396..3360.396 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=3 read=35275
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=1.539..2492.381 rows=1500000 loops=1)
                                 Buffers: shared hit=3 read=35275
 Total runtime: 75670.830 ms
(21 rows)

COMMIT;
COMMIT