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=847833.14..847833.64 rows=200 width=8) (actual time=29618.905..29618.909 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=157923 read=132145 dirtied=234 written=1518
   ->  HashAggregate  (cost=847823.50..847825.50 rows=200 width=8) (actual time=29618.813..29618.820 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=157920 read=132145 dirtied=234 written=1518
         ->  HashAggregate  (cost=810323.50..825323.50 rows=1500000 width=8) (actual time=28790.056..29299.093 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=157920 read=132145 dirtied=234 written=1518
               ->  Hash Right Join  (cost=69028.00..735852.33 rows=14894235 width=8) (actual time=1257.619..18874.320 rows=15353608 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=157920 read=132145 dirtied=234 written=1518
                     ->  Seq Scan on orders  (cost=0.00..443410.80 rows=14894235 width=8) (actual time=0.031..8300.748 rows=14853590 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%packages%'::text)
                           Rows Removed by Filter: 161410
                           Buffers: shared hit=157918 read=96869 dirtied=234 written=1518
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1248.882..1248.882 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=0.018..822.534 rows=1500000 loops=1)
                                 Buffers: shared hit=2 read=35276
 Planning time: 3.645 ms
 Execution time: 29640.533 ms
(24 rows)

COMMIT;
COMMIT