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%packages%'
		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=845785.08..845785.58 rows=200 width=8) (actual time=41126.369..41126.372 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=175491 read=113565 written=13
   ->  HashAggregate  (cost=845775.44..845777.44 rows=200 width=8) (actual time=41126.273..41126.278 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=175488 read=113565 written=13
         ->  HashAggregate  (cost=808275.44..823275.44 rows=1500000 width=8) (actual time=39988.501..40794.075 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=175488 read=113565 written=13
               ->  Hash Right Join  (cost=69028.00..733875.98 rows=14879892 width=8) (actual time=1375.903..23576.616 rows=15352734 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=175488 read=113565 written=13
                     ->  Seq Scan on orders  (cost=0.00..441649.60 rows=14879892 width=8) (actual time=0.033..9351.291 rows=14852713 loops=1)
                           Filter: ((o_comment)::text !~~ '%unusual%packages%'::text)
                           Rows Removed by Filter: 162287
                           Buffers: shared hit=175485 read=78290 written=12
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1362.607..1362.607 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=3 read=35275 written=1
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.014..824.038 rows=1500000 loops=1)
                                 Buffers: shared hit=3 read=35275 written=1
 Planning time: 3.573 ms
 Execution time: 41148.172 ms
(24 rows)

COMMIT;
COMMIT