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%packages%'
		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=844431.90..844432.40 rows=200 width=8) (actual time=33082.557..33082.560 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=239247 read=50062 written=2
   ->  HashAggregate  (cost=844422.26..844424.26 rows=200 width=8) (actual time=33082.465..33082.472 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=239244 read=50062 written=2
         ->  HashAggregate  (cost=806922.26..821922.26 rows=1500000 width=8) (actual time=32233.572..32767.501 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=239244 read=50062 written=2
               ->  Hash Right Join  (cost=69028.00..732971.17 rows=14790218 width=8) (actual time=967.101..21873.083 rows=15354087 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=239244 read=50062 written=2
                     ->  Seq Scan on orders  (cost=0.00..442089.90 rows=14790218 width=8) (actual time=0.030..8423.824 rows=14854067 loops=1)
                           Filter: ((o_comment)::text !~~ '%express%packages%'::text)
                           Rows Removed by Filter: 160933
                           Buffers: shared hit=208942 read=45086 written=2
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=931.532..931.532 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=30302 read=4976
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.015..488.880 rows=1500000 loops=1)
                                 Buffers: shared hit=30302 read=4976
 Planning time: 2.907 ms
 Execution time: 33119.409 ms
(24 rows)

COMMIT;
COMMIT