private function _getConnection()
    {
        if (is_resource($this->_db)) {
            return $this->_db;
        } else {
            $this->_db = @sqlite_open($this->_options['cache_db_complete_path']);
            if (!(is_resource($this->_db))) {
                Zend_Cache::throwException("Impossible to open " . $this->_options['cache_db_complete_path'] . " cache DB file");
            }
            return $this->_db;
        }
    }