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%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=924187.62..924188.12 rows=200 width=8) (actual time=69677.722..69677.723 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=286990 read=3078 written=215
   ->  HashAggregate  (cost=924177.97..924179.97 rows=200 width=8) (actual time=69677.596..69677.608 rows=46 loops=1)
         Buffers: shared hit=286987 read=3078 written=215
         ->  HashAggregate  (cost=886677.97..901677.97 rows=1500000 width=8) (actual time=68522.264..69364.947 rows=1500000 loops=1)
               Buffers: shared hit=286987 read=3078 written=215
               ->  Hash Right Join  (cost=69028.00..811830.14 rows=14969567 width=8) (actual time=1658.032..48644.354 rows=15354117 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=286987 read=3078 written=215
                     ->  Seq Scan on orders  (cost=0.00..443410.80 rows=14969567 width=8) (actual time=0.040..12421.830 rows=14854096 loops=1)
                           Filter: ((o_comment)::text !~~ '%express%packages%'::text)
                           Rows Removed by Filter: 160904
                           Buffers: shared hit=251709 read=3078 written=215
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1656.049..1656.049 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=0.017..952.084 rows=1500000 loops=1)
                                 Buffers: shared hit=35278
 Total runtime: 69712.036 ms
(21 rows)

COMMIT;
COMMIT