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 '%express%deposits%'
		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=923982.93..923983.43 rows=200 width=8) (actual time=74726.220..74726.221 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=284614 read=6215 dirtied=77
   ->  HashAggregate  (cost=923973.29..923975.29 rows=200 width=8) (actual time=74726.072..74726.084 rows=46 loops=1)
         Buffers: shared hit=284611 read=6215 dirtied=77
         ->  HashAggregate  (cost=886473.29..901473.29 rows=1500000 width=8) (actual time=73377.441..74334.268 rows=1500000 loops=1)
               Buffers: shared hit=284611 read=6215 dirtied=77
               ->  Hash Right Join  (cost=69028.00..811931.27 rows=14908404 width=8) (actual time=1725.855..53229.218 rows=15354647 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=284611 read=6215 dirtied=77
                     ->  Seq Scan on orders  (cost=0.00..444735.19 rows=14908404 width=8) (actual time=0.038..14911.348 rows=14854629 loops=1)
                           Filter: ((o_comment)::text !~~ '%express%deposits%'::text)
                           Rows Removed by Filter: 160371
                           Buffers: shared hit=249333 read=6215 dirtied=77
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1723.438..1723.438 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=35278
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.019..953.949 rows=1500000 loops=1)
                                 Buffers: shared hit=35278
 Total runtime: 74758.854 ms
(21 rows)

COMMIT;
COMMIT