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=845056.70..845057.20 rows=200 width=8) (actual time=23867.158..23867.161 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=259328 read=29475
   ->  HashAggregate  (cost=845047.06..845049.06 rows=200 width=8) (actual time=23867.002..23867.011 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=259325 read=29475
         ->  HashAggregate  (cost=807547.06..822547.06 rows=1500000 width=8) (actual time=23168.301..23576.697 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=259325 read=29475
               ->  Hash Right Join  (cost=69028.00..733219.62 rows=14865488 width=8) (actual time=934.398..15633.641 rows=15353670 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=259325 read=29475
                     ->  Seq Scan on orders  (cost=0.00..441209.30 rows=14865488 width=8) (actual time=0.033..6826.312 rows=14853650 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%packages%'::text)
                           Rows Removed by Filter: 161350
                           Buffers: shared hit=246355 read=7167
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=923.728..923.728 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=12970 read=22308
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.017..544.520 rows=1500000 loops=1)
                                 Buffers: shared hit=12970 read=22308
 Planning time: 4.748 ms
 Execution time: 23885.344 ms
(24 rows)

COMMIT;
COMMIT