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 '%special%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=926256.08..926256.58 rows=200 width=8) (actual time=64666.900..64666.902 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=290829
   ->  HashAggregate  (cost=926246.44..926248.44 rows=200 width=8) (actual time=64666.790..64666.800 rows=46 loops=1)
         Buffers: shared hit=290826
         ->  HashAggregate  (cost=888746.44..903746.44 rows=1500000 width=8) (actual time=63437.679..64333.526 rows=1500000 loops=1)
               Buffers: shared hit=290826
               ->  Hash Right Join  (cost=69028.00..813749.79 rows=14999330 width=8) (actual time=1582.772..46406.642 rows=15353284 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=290826
                     ->  Seq Scan on orders  (cost=0.00..444735.19 rows=14999330 width=8) (actual time=0.037..10132.001 rows=14853267 loops=1)
                           Filter: ((o_comment)::text !~~ '%special%packages%'::text)
                           Rows Removed by Filter: 161733
                           Buffers: shared hit=255548
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1580.355..1580.355 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=0.013..561.011 rows=1500000 loops=1)
                                 Buffers: shared hit=35278
 Total runtime: 64721.946 ms
(21 rows)

COMMIT;
COMMIT