public function getLobAsString()
    {
        if ($this->_lobAsString === null) {
            // if never set by user, we use driver option if it exists otherwise false
            if (isset($this->_config['driver_options']) &&
                isset($this->_config['driver_options']['lob_as_string'])) {
                $this->_lobAsString = (bool) $this->_config['driver_options']['lob_as_string'];
            } else {
                $this->_lobAsString = false;
            }
        }
        return $this->_lobAsString;
    }