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=918251.49..918251.99 rows=200 width=8) (actual time=37692.526..37692.528 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=280249 read=8554
   ->  HashAggregate  (cost=918241.85..918243.85 rows=200 width=8) (actual time=37692.411..37692.414 rows=46 loops=1)
         Buffers: shared hit=280246 read=8554
         ->  HashAggregate  (cost=880741.85..895741.85 rows=1500000 width=8) (actual time=36917.518..37391.138 rows=1500000 loops=1)
               Buffers: shared hit=280246 read=8554
               ->  Hash Right Join  (cost=69028.00..806640.94 rows=14820182 width=8) (actual time=814.152..28188.660 rows=15353065 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=280246 read=8554
                     ->  Seq Scan on orders  (cost=0.00..441209.30 rows=14820182 width=8) (actual time=0.037..7634.000 rows=14853047 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%accounts%'::text)
                           Rows Removed by Filter: 161953
                           Buffers: shared hit=252462 read=1060
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=812.679..812.679 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=27784 read=7494
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.022..472.277 rows=1500000 loops=1)
                                 Buffers: shared hit=27784 read=7494
 Total runtime: 37724.675 ms
(21 rows)

COMMIT;
COMMIT