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 '%pending%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=845624.86..845625.36 rows=200 width=8) (actual time=48932.185..48932.188 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=236991 read=52318 written=101
   ->  HashAggregate  (cost=845615.22..845617.22 rows=200 width=8) (actual time=48932.081..48932.091 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=236988 read=52318 written=101
         ->  HashAggregate  (cost=808115.22..823115.22 rows=1500000 width=8) (actual time=47748.758..48597.537 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=236988 read=52318 written=101
               ->  Hash Right Join  (cost=69028.00..733865.89 rows=14849866 width=8) (actual time=1050.128..29250.494 rows=15353656 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=236988 read=52318 written=101
                     ->  Seq Scan on orders  (cost=0.00..442089.90 rows=14849866 width=8) (actual time=0.028..8517.668 rows=14853638 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%packages%'::text)
                           Rows Removed by Filter: 161362
                           Buffers: shared hit=209073 read=44955 written=101
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1038.317..1038.317 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=27915 read=7363
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.016..601.607 rows=1500000 loops=1)
                                 Buffers: shared hit=27915 read=7363
 Planning time: 3.379 ms
 Execution time: 48955.454 ms
(24 rows)

COMMIT;
COMMIT