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=925874.18..925874.68 rows=200 width=8) (actual time=64961.997..64962.001 rows=45 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=290728 read=101
   ->  HashAggregate  (cost=925864.54..925866.54 rows=200 width=8) (actual time=64961.896..64961.908 rows=45 loops=1)
         Buffers: shared hit=290725 read=101
         ->  HashAggregate  (cost=888364.54..903364.54 rows=1500000 width=8) (actual time=63708.663..64621.543 rows=1500000 loops=1)
               Buffers: shared hit=290725 read=101
               ->  Hash Right Join  (cost=69028.00..813444.27 rows=14984054 width=8) (actual time=1721.862..46491.684 rows=15352907 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=290725 read=101
                     ->  Seq Scan on orders  (cost=0.00..444735.19 rows=14984054 width=8) (actual time=0.051..11144.857 rows=14852888 loops=1)
                           Filter: ((o_comment)::text !~~ '%unusual%deposits%'::text)
                           Rows Removed by Filter: 162112
                           Buffers: shared hit=255520 read=28
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1719.622..1719.622 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=35205 read=73
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.021..959.854 rows=1500000 loops=1)
                                 Buffers: shared hit=35205 read=73
 Total runtime: 64991.822 ms
(21 rows)

COMMIT;
COMMIT