Method max_key_part_length

sql/handler.h:4749–4750

  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()); }

  virtual uint max_supported_record_length() const { return HA_MAX_REC_LENGTH; }
  virtual uint max_supported_keys() const { return 0; }