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 '%unusual%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=849876.83..849877.33 rows=200 width=8) (actual time=44417.031..44417.033 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=197492 read=93590 written=755
   ->  HashAggregate  (cost=849867.19..849869.19 rows=200 width=8) (actual time=44416.913..44416.923 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=197489 read=93590 written=755
         ->  HashAggregate  (cost=812367.19..827367.19 rows=1500000 width=8) (actual time=43209.300..44086.930 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=197489 read=93590 written=755
               ->  Hash Right Join  (cost=69028.00..737826.26 rows=14908185 width=8) (actual time=1062.943..25980.565 rows=15353775 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=197489 read=93590 written=755
                     ->  Seq Scan on orders  (cost=0.00..445175.49 rows=14908185 width=8) (actual time=0.029..8740.827 rows=14853753 loops=1)
                           Filter: ((o_comment)::text !~~ '%unusual%accounts%'::text)
                           Rows Removed by Filter: 161247
                           Buffers: shared hit=184882 read=70919 written=721
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1054.065..1054.065 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=12607 read=22671 written=34
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.016..643.099 rows=1500000 loops=1)
                                 Buffers: shared hit=12607 read=22671 written=34
 Planning time: 2.769 ms
 Execution time: 44444.520 ms
(24 rows)

COMMIT;
COMMIT