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=852463.69..852464.19 rows=200 width=8) (actual time=26321.146..26321.149 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=252697 read=38132 written=48
   ->  HashAggregate  (cost=852454.05..852456.05 rows=200 width=8) (actual time=26321.062..26321.073 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=252694 read=38132 written=48
         ->  HashAggregate  (cost=814954.05..829954.05 rows=1500000 width=8) (actual time=25537.221..25984.723 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=252694 read=38132 written=48
               ->  Hash Right Join  (cost=69028.00..739656.33 rows=15059543 width=8) (actual time=808.403..16907.805 rows=15353086 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=252694 read=38132 written=48
                     ->  Seq Scan on orders  (cost=0.00..444735.19 rows=15059543 width=8) (actual time=0.024..7188.828 rows=14853070 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%accounts%'::text)
                           Rows Removed by Filter: 161930
                           Buffers: shared hit=217416 read=38132 written=48
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=802.144..802.144 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=35278
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.010..418.747 rows=1500000 loops=1)
                                 Buffers: shared hit=35278
 Planning time: 2.400 ms
 Execution time: 26334.906 ms
(24 rows)

COMMIT;
COMMIT