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=921375.74..921376.24 rows=200 width=8) (actual time=78198.827..78198.832 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=261261 read=28048
   ->  HashAggregate  (cost=921366.10..921368.10 rows=200 width=8) (actual time=78198.721..78198.731 rows=46 loops=1)
         Buffers: shared hit=261258 read=28048
         ->  HashAggregate  (cost=883866.10..898866.10 rows=1500000 width=8) (actual time=77091.455..77842.256 rows=1500000 loops=1)
               Buffers: shared hit=261258 read=28048
               ->  Hash Right Join  (cost=69028.00..809316.46 rows=14909928 width=8) (actual time=3192.346..57455.767 rows=15354087 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=261258 read=28048
                     ->  Seq Scan on orders  (cost=0.00..442089.90 rows=14909928 width=8) (actual time=0.031..16357.531 rows=14854067 loops=1)
                           Filter: ((o_comment)::text !~~ '%express%packages%'::text)
                           Rows Removed by Filter: 160933
                           Buffers: shared hit=251201 read=2827
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=3189.911..3189.911 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=10057 read=25221
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.023..2257.850 rows=1500000 loops=1)
                                 Buffers: shared hit=10057 read=25221
 Total runtime: 78239.024 ms
(21 rows)

COMMIT;
COMMIT