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=927173.88..927174.38 rows=200 width=8) (actual time=64145.641..64145.641 rows=45 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=248240 read=43348 dirtied=253 written=120
   ->  HashAggregate  (cost=927164.24..927166.24 rows=200 width=8) (actual time=64145.507..64145.520 rows=45 loops=1)
         Buffers: shared hit=248237 read=43348 dirtied=253 written=120
         ->  HashAggregate  (cost=889664.24..904664.24 rows=1500000 width=8) (actual time=62886.735..63791.839 rows=1500000 loops=1)
               Buffers: shared hit=248237 read=43348 dirtied=253 written=120
               ->  Hash Right Join  (cost=69028.00..814748.21 rows=14983206 width=8) (actual time=1786.428..45128.426 rows=15353563 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=248237 read=43348 dirtied=253 written=120
                     ->  Seq Scan on orders  (cost=0.00..446056.09 rows=14983206 width=8) (actual time=0.047..10403.424 rows=14853545 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%packages%'::text)
                           Rows Removed by Filter: 161455
                           Buffers: shared hit=248235 read=8072 dirtied=253 written=99
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1783.692..1783.692 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=2 read=35276 written=21
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.021..1109.748 rows=1500000 loops=1)
                                 Buffers: shared hit=2 read=35276 written=21
 Total runtime: 64190.624 ms
(21 rows)

COMMIT;
COMMIT