public static function getRootPageSettingList()
    {
        static $cache = null;

        if ($cache === null) {
            $query = 'SELECT seosr.*
                        FROM tx_metaseo_setting_root seosr
                             INNER JOIN pages p
                                 ON p.uid = seosr.pid
                                AND p.is_siteroot = 1
                                AND p.deleted = 0
                       WHERE seosr.deleted = 0';
            $cache = DatabaseUtility::getAllWithIndex($query, 'pid');
        }

        return $cache;
    }