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=924740.21..924740.71 rows=200 width=8) (actual time=91258.671..91258.674 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=283873 read=6956
   ->  HashAggregate  (cost=924730.56..924732.56 rows=200 width=8) (actual time=91258.559..91258.569 rows=46 loops=1)
         Buffers: shared hit=283870 read=6956
         ->  HashAggregate  (cost=887230.56..902230.56 rows=1500000 width=8) (actual time=90114.551..90901.359 rows=1500000 loops=1)
               Buffers: shared hit=283870 read=6956
               ->  Hash Right Join  (cost=69028.00..812537.09 rows=14938695 width=8) (actual time=2858.268..67139.727 rows=15354096 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=283870 read=6956
                     ->  Seq Scan on orders  (cost=0.00..444735.19 rows=14938695 width=8) (actual time=0.046..19533.129 rows=14854075 loops=1)
                           Filter: ((o_comment)::text !~~ '%express%packages%'::text)
                           Rows Removed by Filter: 160925
                           Buffers: shared hit=254036 read=1512
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=2856.062..2856.062 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=29834 read=5444
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.012..1815.654 rows=1500000 loops=1)
                                 Buffers: shared hit=29834 read=5444
 Total runtime: 91305.012 ms
(21 rows)

COMMIT;
COMMIT