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%accounts%'
		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=928742.63..928743.13 rows=200 width=8) (actual time=78679.668..78679.672 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=241817 read=50024 dirtied=253 written=193
   ->  HashAggregate  (cost=928732.99..928734.99 rows=200 width=8) (actual time=78679.508..78679.519 rows=46 loops=1)
         Buffers: shared hit=241814 read=50024 dirtied=253 written=193
         ->  HashAggregate  (cost=891232.99..906232.99 rows=1500000 width=8) (actual time=77495.996..78325.692 rows=1500000 loops=1)
               Buffers: shared hit=241814 read=50024 dirtied=253 written=193
               ->  Hash Right Join  (cost=69028.00..816091.27 rows=15028344 width=8) (actual time=3404.362..56141.146 rows=15353138 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=241814 read=50024 dirtied=253 written=193
                     ->  Seq Scan on orders  (cost=0.00..446496.39 rows=15028344 width=8) (actual time=0.045..13136.609 rows=14853122 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%accounts%'::text)
                           Rows Removed by Filter: 161878
                           Buffers: shared hit=241812 read=14748 dirtied=253 written=172
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=3402.400..3402.400 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=2 read=35276 written=21
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.016..2259.080 rows=1500000 loops=1)
                                 Buffers: shared hit=2 read=35276 written=21
 Total runtime: 78735.340 ms
(21 rows)

COMMIT;
COMMIT