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=851222.99..851223.49 rows=200 width=8) (actual time=40788.152..40788.156 rows=45 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=211929 read=79406 dirtied=127 written=1972
   ->  HashAggregate  (cost=851213.35..851215.35 rows=200 width=8) (actual time=40788.044..40788.054 rows=45 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=211926 read=79406 dirtied=127 written=1972
         ->  HashAggregate  (cost=813713.35..828713.35 rows=1500000 width=8) (actual time=39913.979..40467.351 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=211926 read=79406 dirtied=127 written=1972
               ->  Hash Right Join  (cost=69028.00..738945.96 rows=14953478 width=8) (actual time=1237.545..25144.648 rows=15339856 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=211926 read=79406 dirtied=127 written=1972
                     ->  Seq Scan on orders  (cost=0.00..445615.79 rows=14953478 width=8) (actual time=0.025..9299.658 rows=14839838 loops=1)
                           Filter: ((o_comment)::text !~~ '%express%deposits%'::text)
                           Rows Removed by Filter: 160162
                           Buffers: shared hit=211924 read=44130 dirtied=127 written=1968
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1221.282..1221.282 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=2 read=35276 written=4
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.011..774.007 rows=1500000 loops=1)
                                 Buffers: shared hit=2 read=35276 written=4
 Planning time: 3.270 ms
 Execution time: 40825.017 ms
(24 rows)

COMMIT;
COMMIT