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 '%unusual%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=847977.99..847978.49 rows=200 width=8) (actual time=33233.706..33233.710 rows=45 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=198189 read=92133 dirtied=104 written=1267
   ->  HashAggregate  (cost=847968.35..847970.35 rows=200 width=8) (actual time=33233.615..33233.623 rows=45 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=198186 read=92133 dirtied=104 written=1267
         ->  HashAggregate  (cost=810468.35..825468.35 rows=1500000 width=8) (actual time=32421.399..32917.120 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=198186 read=92133 dirtied=104 written=1267
               ->  Hash Right Join  (cost=69028.00..736071.47 rows=14879375 width=8) (actual time=1738.196..19615.806 rows=15338054 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=198186 read=92133 dirtied=104 written=1267
                     ->  Seq Scan on orders  (cost=0.00..443852.85 rows=14879375 width=8) (actual time=0.034..8162.793 rows=14838035 loops=1)
                           Filter: ((o_comment)::text !~~ '%unusual%deposits%'::text)
                           Rows Removed by Filter: 161965
                           Buffers: shared hit=198184 read=56857 dirtied=104 written=1267
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1234.458..1234.458 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=2 read=35276
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.019..759.769 rows=1500000 loops=1)
                                 Buffers: shared hit=2 read=35276
 Planning time: 3.218 ms
 Execution time: 33263.091 ms
(24 rows)

COMMIT;
COMMIT