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 '%special%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=919002.97..919003.47 rows=200 width=8) (actual time=45860.837..45860.839 rows=45 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=279900 read=8903
   ->  HashAggregate  (cost=918993.33..918995.33 rows=200 width=8) (actual time=45860.704..45860.710 rows=45 loops=1)
         Buffers: shared hit=279897 read=8903
         ->  HashAggregate  (cost=881493.33..896493.33 rows=1500000 width=8) (actual time=44638.219..45561.809 rows=1500000 loops=1)
               Buffers: shared hit=279897 read=8903
               ->  Hash Right Join  (cost=69028.00..807242.12 rows=14850241 width=8) (actual time=891.265..32602.831 rows=15352885 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=279897 read=8903
                     ->  Seq Scan on orders  (cost=0.00..441209.30 rows=14850241 width=8) (actual time=0.038..8571.040 rows=14852865 loops=1)
                           Filter: ((o_comment)::text !~~ '%special%deposits%'::text)
                           Rows Removed by Filter: 162135
                           Buffers: shared hit=252101 read=1421
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=888.040..888.040 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=27796 read=7482
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.023..479.750 rows=1500000 loops=1)
                                 Buffers: shared hit=27796 read=7482
 Total runtime: 45885.977 ms
(21 rows)

COMMIT;
COMMIT