public function callKeywords($index, $text, $fetchStatistic, &$params)
    {
        $indexParamName = self::PARAM_PREFIX . count($params);
        $params[$indexParamName] = $index;
        $textParamName = self::PARAM_PREFIX . count($params);
        $params[$textParamName] = $text;

        return 'CALL KEYWORDS(' . $textParamName . ', ' . $indexParamName . ($fetchStatistic ? ', 1' : '') . ')';
    }