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=927931.83..927932.33 rows=200 width=8) (actual time=71572.516..71572.518 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=284008 read=7580 written=116
   ->  HashAggregate  (cost=927922.19..927924.19 rows=200 width=8) (actual time=71572.389..71572.401 rows=46 loops=1)
         Buffers: shared hit=284005 read=7580 written=116
         ->  HashAggregate  (cost=890422.19..905422.19 rows=1500000 width=8) (actual time=70361.716..71214.877 rows=1500000 loops=1)
               Buffers: shared hit=284005 read=7580 written=116
               ->  Hash Right Join  (cost=69028.00..815354.57 rows=15013524 width=8) (actual time=2012.158..51287.439 rows=15338298 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=284005 read=7580 written=116
                     ->  Seq Scan on orders  (cost=0.00..446056.09 rows=15013524 width=8) (actual time=0.058..14544.542 rows=14838282 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%accounts%'::text)
                           Rows Removed by Filter: 161718
                           Buffers: shared hit=249761 read=6546 written=32
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=2010.525..2010.525 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=34244 read=1034 written=84
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.012..1205.542 rows=1500000 loops=1)
                                 Buffers: shared hit=34244 read=1034 written=84
 Total runtime: 71598.439 ms
(21 rows)

COMMIT;
COMMIT