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=847674.39..847674.89 rows=200 width=8) (actual time=35220.446..35220.446 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=253020 read=37302 written=1086
   ->  HashAggregate  (cost=847664.75..847666.75 rows=200 width=8) (actual time=35220.342..35220.353 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=253017 read=37302 written=1086
         ->  HashAggregate  (cost=810164.75..825164.75 rows=1500000 width=8) (actual time=34389.365..34892.070 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=253017 read=37302 written=1086
               ->  Hash Right Join  (cost=69028.00..735843.77 rows=14864195 width=8) (actual time=1082.703..20916.598 rows=15353590 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=253017 read=37302 written=1086
                     ->  Seq Scan on orders  (cost=0.00..443852.85 rows=14864195 width=8) (actual time=0.029..8057.550 rows=14853572 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%packages%'::text)
                           Rows Removed by Filter: 161428
                           Buffers: shared hit=217739 read=37302 written=1086
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1066.343..1066.343 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=35278
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.017..535.456 rows=1500000 loops=1)
                                 Buffers: shared hit=35278
 Planning time: 3.065 ms
 Execution time: 35252.469 ms
(24 rows)

COMMIT;
COMMIT