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=924177.69..924178.19 rows=200 width=8) (actual time=84465.118..84465.122 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=262485 read=27583 written=1
   ->  HashAggregate  (cost=924168.05..924170.05 rows=200 width=8) (actual time=84465.001..84465.011 rows=46 loops=1)
         Buffers: shared hit=262482 read=27583 written=1
         ->  HashAggregate  (cost=886668.05..901668.05 rows=1500000 width=8) (actual time=83384.927..84135.494 rows=1500000 loops=1)
               Buffers: shared hit=262482 read=27583 written=1
               ->  Hash Right Join  (cost=69028.00..811822.20 rows=14969170 width=8) (actual time=2337.812..61785.036 rows=15352769 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=262482 read=27583 written=1
                     ->  Seq Scan on orders  (cost=0.00..443410.80 rows=14969170 width=8) (actual time=0.049..19944.586 rows=14852748 loops=1)
                           Filter: ((o_comment)::text !~~ '%unusual%packages%'::text)
                           Rows Removed by Filter: 162252
                           Buffers: shared hit=227204 read=27583 written=1
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=2335.928..2335.928 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=35278
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.018..1554.814 rows=1500000 loops=1)
                                 Buffers: shared hit=35278
 Total runtime: 84498.662 ms
(21 rows)

COMMIT;
COMMIT