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 '%unusual%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=919439.24..919439.74 rows=200 width=8) (actual time=78237.036..78237.037 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=143725 read=145331 written=9
   ->  HashAggregate  (cost=919429.60..919431.60 rows=200 width=8) (actual time=78236.913..78236.929 rows=46 loops=1)
         Buffers: shared hit=143722 read=145331 written=9
         ->  HashAggregate  (cost=881929.60..896929.60 rows=1500000 width=8) (actual time=77065.679..77898.281 rows=1500000 loops=1)
               Buffers: shared hit=143722 read=145331 written=9
               ->  Hash Right Join  (cost=69028.00..807679.20 rows=14850080 width=8) (actual time=1968.782..53135.488 rows=15352734 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=143722 read=145331 written=9
                     ->  Seq Scan on orders  (cost=0.00..441649.60 rows=14850080 width=8) (actual time=0.030..12492.783 rows=14852713 loops=1)
                           Filter: ((o_comment)::text !~~ '%unusual%packages%'::text)
                           Rows Removed by Filter: 162287
                           Buffers: shared hit=116071 read=137704 written=9
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=1966.605..1966.605 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=27651 read=7627
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.011..981.734 rows=1500000 loops=1)
                                 Buffers: shared hit=27651 read=7627
 Total runtime: 78303.795 ms
(21 rows)

COMMIT;
COMMIT