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 '%pending%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=927553.56..927554.06 rows=200 width=8) (actual time=63365.771..63365.774 rows=45 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=254390 read=37198 written=9
   ->  HashAggregate  (cost=927543.91..927545.91 rows=200 width=8) (actual time=63365.645..63365.656 rows=45 loops=1)
         Buffers: shared hit=254387 read=37198 written=9
         ->  HashAggregate  (cost=890043.91..905043.91 rows=1500000 width=8) (actual time=62092.930..63025.249 rows=1500000 loops=1)
               Buffers: shared hit=254387 read=37198 written=9
               ->  Hash Right Join  (cost=69028.00..815051.95 rows=14998393 width=8) (actual time=1682.445..44823.065 rows=15353563 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=254387 read=37198 written=9
                     ->  Seq Scan on orders  (cost=0.00..446056.09 rows=14998393 width=8) (actual time=0.042..10205.246 rows=14853545 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%packages%'::text)
                           Rows Removed by Filter: 161455
                           Buffers: shared hit=254331 read=1976 written=9
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1680.445..1680.445 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=56 read=35222
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.018..999.996 rows=1500000 loops=1)
                                 Buffers: shared hit=56 read=35222
 Total runtime: 63400.833 ms
(21 rows)

COMMIT;
COMMIT