select from collect-aggregate function

Description:
Topic: select * from collect(..)
select t.region_id, tt.*
from (select t.region_id,
collect(t.country_id
order by t.country_id) as country_ids
from (select t.region_id, t.country_id
from hr.countries t
where t.region_id = 20
) t
group by t.region_id
) t, table(t.country_ids) tt;