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=851384.17..851384.67 rows=200 width=8) (actual time=46645.875..46645.878 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=198859 read=92223 dirtied=253 written=605
   ->  HashAggregate  (cost=851374.53..851376.53 rows=200 width=8) (actual time=46645.758..46645.767 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=198856 read=92223 dirtied=253 written=605
         ->  HashAggregate  (cost=813874.53..828874.53 rows=1500000 width=8) (actual time=45380.880..46300.840 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=198856 read=92223 dirtied=253 written=605
               ->  Hash Right Join  (cost=69028.00..738956.77 rows=14983552 width=8) (actual time=1266.019..26452.862 rows=15353109 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=198856 read=92223 dirtied=253 written=605
                     ->  Seq Scan on orders  (cost=0.00..445175.49 rows=14983552 width=8) (actual time=0.031..9173.010 rows=14853093 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%accounts%'::text)
                           Rows Removed by Filter: 161907
                           Buffers: shared hit=186914 read=68887 dirtied=253 written=561
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1253.701..1253.701 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=11942 read=23336 written=44
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.019..799.896 rows=1500000 loops=1)
                                 Buffers: shared hit=11942 read=23336 written=44
 Planning time: 4.202 ms
 Execution time: 46680.298 ms
(24 rows)

COMMIT;
COMMIT