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=855417.65..855418.15 rows=200 width=8) (actual time=26405.284..26405.285 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=229966 read=61875 written=115
   ->  HashAggregate  (cost=855408.01..855410.01 rows=200 width=8) (actual time=26405.212..26405.224 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=229963 read=61875 written=115
         ->  HashAggregate  (cost=817908.01..832908.01 rows=1500000 width=8) (actual time=25636.953..26073.086 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=229963 read=61875 written=115
               ->  Hash Right Join  (cost=69028.00..742312.10 rows=15119181 width=8) (actual time=796.323..17049.511 rows=15338309 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=229963 read=61875 written=115
                     ->  Seq Scan on orders  (cost=0.00..446496.39 rows=15119181 width=8) (actual time=0.018..7304.784 rows=14838293 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%accounts%'::text)
                           Rows Removed by Filter: 161707
                           Buffers: shared hit=194685 read=61875 written=115
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=790.145..790.145 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=0.011..407.816 rows=1500000 loops=1)
                                 Buffers: shared hit=35278
 Planning time: 2.623 ms
 Execution time: 26418.257 ms
(24 rows)

COMMIT;
COMMIT