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=850783.37..850783.87 rows=200 width=8) (actual time=46119.413..46119.416 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=211825 read=79257 written=586
   ->  HashAggregate  (cost=850773.73..850775.73 rows=200 width=8) (actual time=46119.288..46119.300 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=211822 read=79257 written=586
         ->  HashAggregate  (cost=813273.73..828273.73 rows=1500000 width=8) (actual time=44912.066..45794.419 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=211822 read=79257 written=586
               ->  Hash Right Join  (cost=69028.00..738506.17 rows=14953512 width=8) (actual time=1100.029..24925.627 rows=15353622 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=211822 read=79257 written=586
                     ->  Seq Scan on orders  (cost=0.00..445175.49 rows=14953512 width=8) (actual time=0.031..8588.146 rows=14853604 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%packages%'::text)
                           Rows Removed by Filter: 161396
                           Buffers: shared hit=176544 read=79257 written=586
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1085.471..1085.471 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=0.019..569.946 rows=1500000 loops=1)
                                 Buffers: shared hit=35278
 Planning time: 3.138 ms
 Execution time: 46155.538 ms
(24 rows)

COMMIT;
COMMIT