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=931009.18..931009.68 rows=200 width=8) (actual time=61512.305..61512.309 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=247536 read=44305 written=1
   ->  HashAggregate  (cost=930999.54..931001.54 rows=200 width=8) (actual time=61512.199..61512.209 rows=46 loops=1)
         Buffers: shared hit=247533 read=44305 written=1
         ->  HashAggregate  (cost=893499.54..908499.54 rows=1500000 width=8) (actual time=60348.798..61173.304 rows=1500000 loops=1)
               Buffers: shared hit=247533 read=44305 written=1
               ->  Hash Right Join  (cost=69028.00..817904.51 rows=15119006 width=8) (actual time=1471.415..43589.665 rows=15338055 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=247533 read=44305 written=1
                     ->  Seq Scan on orders  (cost=0.00..446496.39 rows=15119006 width=8) (actual time=0.041..9875.258 rows=14838036 loops=1)
                           Filter: ((o_comment)::text !~~ '%unusual%deposits%'::text)
                           Rows Removed by Filter: 161964
                           Buffers: shared hit=247531 read=9029 written=1
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1469.245..1469.245 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=2 read=35276
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.010..845.524 rows=1500000 loops=1)
                                 Buffers: shared hit=2 read=35276
 Total runtime: 61545.519 ms
(21 rows)

COMMIT;
COMMIT