private function _fill()
    {

        if (empty($this->db)) return false;

        $sql = (string)"SHOW VARIABLES";
        $res = $this->db->query((string)$sql);

        if (!$res) return false;

        $data = $this->db->fetch_assoc_list($res);
        if (!empty($data)) {
            foreach ($data as $variable) {
                $this->$variable[(string)'Variable_name'] = (string)$variable['Value'];
            }
            $this->db->free($res);
        }

        // clear all the unecessary variables and the endles recursion of the db
        unset($this->db, $data, $variable);

        return true;
    }