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%accounts%'
		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=930309.68..930310.18 rows=200 width=8) (actual time=85965.165..85965.170 rows=45 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=263960 read=28134 dirtied=252 written=48
   ->  HashAggregate  (cost=930300.04..930302.04 rows=200 width=8) (actual time=85964.993..85965.005 rows=45 loops=1)
         Buffers: shared hit=263957 read=28134 dirtied=252 written=48
         ->  HashAggregate  (cost=892800.04..907800.04 rows=1500000 width=8) (actual time=84805.708..85602.678 rows=1500000 loops=1)
               Buffers: shared hit=263957 read=28134 dirtied=252 written=48
               ->  Hash Right Join  (cost=69028.00..817432.97 rows=15073414 width=8) (actual time=2498.013..62570.952 rows=15353157 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=263957 read=28134 dirtied=252 written=48
                     ->  Seq Scan on orders  (cost=0.00..446936.69 rows=15073414 width=8) (actual time=0.048..19546.126 rows=14853141 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%accounts%'::text)
                           Rows Removed by Filter: 161859
                           Buffers: shared hit=231908 read=24905 dirtied=252 written=2
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=2496.140..2496.140 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=32049 read=3229 written=46
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.016..1734.350 rows=1500000 loops=1)
                                 Buffers: shared hit=32049 read=3229 written=46
 Total runtime: 85996.407 ms
(21 rows)

COMMIT;
COMMIT