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 '%special%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=919757.29..919757.79 rows=200 width=8) (actual time=47473.396..47473.398 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=279509 read=9294
   ->  HashAggregate  (cost=919747.65..919749.65 rows=200 width=8) (actual time=47473.295..47473.303 rows=46 loops=1)
         Buffers: shared hit=279506 read=9294
         ->  HashAggregate  (cost=882247.65..897247.65 rows=1500000 width=8) (actual time=46261.494..47172.731 rows=1500000 loops=1)
               Buffers: shared hit=279506 read=9294
               ->  Hash Right Join  (cost=69028.00..807845.58 rows=14880414 width=8) (actual time=802.750..33842.998 rows=15353288 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=279506 read=9294
                     ->  Seq Scan on orders  (cost=0.00..441209.30 rows=14880414 width=8) (actual time=0.040..8416.235 rows=14853269 loops=1)
                           Filter: ((o_comment)::text !~~ '%special%packages%'::text)
                           Rows Removed by Filter: 161731
                           Buffers: shared hit=251710 read=1812
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=801.792..801.792 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=27796 read=7482
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.026..465.642 rows=1500000 loops=1)
                                 Buffers: shared hit=27796 read=7482
 Total runtime: 47498.635 ms
(21 rows)

COMMIT;
COMMIT