在postgres中如何查找数组中的最短字符串

SELECT array_agg(str) AS shortest_strings
FROM (
  SELECT str
  FROM unnest(array['string1', 'string22', 'string333']) AS str
  WHERE length(str) = (
    SELECT min(length(str))
    FROM unnest(array['string1', 'string22', 'string333']) AS str
  )
) AS shortest;