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=927176.43..927176.93 rows=200 width=8) (actual time=65337.431..65337.434 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=246068 read=45520 written=4
   ->  HashAggregate  (cost=927166.79..927168.79 rows=200 width=8) (actual time=65337.315..65337.323 rows=46 loops=1)
         Buffers: shared hit=246065 read=45520 written=4
         ->  HashAggregate  (cost=889666.79..904666.79 rows=1500000 width=8) (actual time=64088.670..64973.648 rows=1500000 loops=1)
               Buffers: shared hit=246065 read=45520 written=4
               ->  Hash Right Join  (cost=69028.00..814750.25 rows=14983308 width=8) (actual time=2074.025..46646.598 rows=15353131 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=246065 read=45520 written=4
                     ->  Seq Scan on orders  (cost=0.00..446056.09 rows=14983308 width=8) (actual time=0.050..10951.593 rows=14853115 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%accounts%'::text)
                           Rows Removed by Filter: 161885
                           Buffers: shared hit=246062 read=10245 written=4
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=2071.926..2071.926 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=3 read=35275
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.014..1297.711 rows=1500000 loops=1)
                                 Buffers: shared hit=3 read=35275
 Total runtime: 65364.558 ms
(21 rows)

COMMIT;
COMMIT