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 '%express%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=846968.24..846968.74 rows=200 width=8) (actual time=44768.930..44768.933 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=200384 read=89178 dirtied=120 written=532
   ->  HashAggregate  (cost=846958.60..846960.60 rows=200 width=8) (actual time=44768.831..44768.845 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=200381 read=89178 dirtied=120 written=532
         ->  HashAggregate  (cost=809458.60..824458.60 rows=1500000 width=8) (actual time=43576.604..44428.316 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=200381 read=89178 dirtied=120 written=532
               ->  Hash Right Join  (cost=69028.00..734983.50 rows=14895020 width=8) (actual time=1269.529..26538.216 rows=15339254 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=200381 read=89178 dirtied=120 written=532
                     ->  Seq Scan on orders  (cost=0.00..442530.20 rows=14895020 width=8) (actual time=0.034..9640.554 rows=14839234 loops=1)
                           Filter: ((o_comment)::text !~~ '%express%packages%'::text)
                           Rows Removed by Filter: 160766
                           Buffers: shared hit=200379 read=53902 dirtied=120 written=532
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1259.080..1259.080 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=2 read=35276
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.012..826.767 rows=1500000 loops=1)
                                 Buffers: shared hit=2 read=35276
 Planning time: 5.306 ms
 Execution time: 45392.920 ms
(24 rows)

COMMIT;
COMMIT