Method max_key_length

sql/handler.h:4747–4748

  uint max_key_parts() const
  { return MY_MIN(MAX_REF_PARTS, max_supported_key_parts()); }
  uint max_key_length() const
  { return MY_MIN(MAX_DATA_LENGTH_FOR_KEY, max_supported_key_length()); }
  uint max_key_part_length() const
  { return MY_MIN(MAX_DATA_LENGTH_FOR_KEY, max_supported_key_part_length()); }