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=852120.87..852121.37 rows=200 width=8) (actual time=47547.039..47547.042 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=275919 read=15416 written=44
   ->  HashAggregate  (cost=852111.23..852113.23 rows=200 width=8) (actual time=47546.896..47546.907 rows=46 loops=1)
         Group Key: count(orders.o_orderkey)
         Buffers: shared hit=275916 read=15416 written=44
         ->  HashAggregate  (cost=814611.23..829611.23 rows=1500000 width=8) (actual time=46260.471..47205.973 rows=1500000 loops=1)
               Group Key: customer.c_custkey
               Buffers: shared hit=275916 read=15416 written=44
               ->  Hash Right Join  (cost=69028.00..739619.37 rows=14998372 width=8) (actual time=1148.892..27079.028 rows=15353127 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=275916 read=15416 written=44
                     ->  Seq Scan on orders  (cost=0.00..445615.79 rows=14998372 width=8) (actual time=0.029..8258.989 rows=14853111 loops=1)
                           Filter: ((o_comment)::text !~~ '%pending%accounts%'::text)
                           Rows Removed by Filter: 161889
                           Buffers: shared hit=242313 read=13741 written=43
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1134.469..1134.469 rows=1500000 loops=1)
                           Buckets: 2097152  Batches: 1  Memory Usage: 69119kB
                           Buffers: shared hit=33603 read=1675 written=1
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.022..649.662 rows=1500000 loops=1)
                                 Buffers: shared hit=33603 read=1675 written=1
 Planning time: 4.484 ms
 Execution time: 48079.241 ms
(24 rows)

COMMIT;
COMMIT