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=917502.17..917502.67 rows=200 width=8) (actual time=32515.962..32515.965 rows=45 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=279364 read=9439
   ->  HashAggregate  (cost=917492.53..917494.53 rows=200 width=8) (actual time=32515.825..32515.829 rows=45 loops=1)
         Buffers: shared hit=279361 read=9439
         ->  HashAggregate  (cost=879992.53..894992.53 rows=1500000 width=8) (actual time=31769.504..32213.819 rows=1500000 loops=1)
               Buffers: shared hit=279361 read=9439
               ->  Hash Right Join  (cost=69028.00..806041.48 rows=14790209 width=8) (actual time=831.167..23944.083 rows=15354693 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=279361 read=9439
                     ->  Seq Scan on orders  (cost=0.00..441209.30 rows=14790209 width=8) (actual time=0.039..8727.946 rows=14854672 loops=1)
                           Filter: ((o_comment)::text !~~ '%express%deposits%'::text)
                           Rows Removed by Filter: 160328
                           Buffers: shared hit=251577 read=1945
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=828.954..828.954 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=27784 read=7494
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.025..491.377 rows=1500000 loops=1)
                                 Buffers: shared hit=27784 read=7494
 Total runtime: 32539.645 ms
(21 rows)

COMMIT;
COMMIT