public function allowRating($sUserId, $sType, $sObjectId)
    {
        $oDb = \OxidEsales\Eshop\Core\DatabaseProvider::getDb();
        $myConfig = \OxidEsales\Eshop\Core\Registry::getConfig();

        if ($iRatingLogsTimeout = $myConfig->getConfigParam('iRatingLogsTimeout')) {
            $sExpDate = date('Y-m-d H:i:s', \OxidEsales\Eshop\Core\Registry::getUtilsDate()->getTime() - $iRatingLogsTimeout * 24 * 60 * 60);
            $oDb->execute("delete from oxratings where oxtimestamp < '$sExpDate'");
        }
        $sSelect = "select oxid from oxratings where oxuserid = " . $oDb->quote($sUserId) . " and oxtype=" . $oDb->quote($sType) . " and oxobjectid = " . $oDb->quote($sObjectId);
        if ($oDb->getOne($sSelect)) {
            return false;
        }

        return true;
    }