BEGIN;
BEGIN
EXPLAIN
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 '%express%deposits%'
		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=1535908.29..1535908.79 rows=200 width=16)
   Sort Key: (count(*)) DESC, (count(orders.o_orderkey)) DESC
   ->  HashAggregate  (cost=1535898.65..1535900.65 rows=200 width=16)
         Group Key: count(orders.o_orderkey)
         ->  Finalize GroupAggregate  (cost=1000.89..1513397.92 rows=1500049 width=12)
               Group Key: customer.c_custkey
               ->  Gather Merge  (cost=1000.89..1483396.94 rows=3000098 width=12)
                     Workers Planned: 2
                     ->  Partial GroupAggregate  (cost=0.86..1136111.16 rows=1500049 width=12)
                           Group Key: customer.c_custkey
                           ->  Nested Loop Left Join  (cost=0.86..1090148.46 rows=6192442 width=12)
                                 ->  Parallel Index Only Scan using pk_customer on customer  (cost=0.43..28594.88 rows=625020 width=4)
                                 ->  Index Scan using orders_o_custkey_idx on orders  (cost=0.43..1.53 rows=17 width=12)
                                       Index Cond: (o_custkey = customer.c_custkey)
                                       Filter: ((o_comment)::text !~~ '%express%deposits%'::text)
(15 rows)

COMMIT;
COMMIT