private function _postgresqlSequenceExists($name)
    {
        $escape = Driver::$escape_char;
        $sql    = "select count(*) as {$escape}CNT{$escape} from information_schema.sequences where sequence_name = '$name'";
        $stmt   = self::query($sql);
        $rst    = $stmt->fetch(\PDO::FETCH_ASSOC);
        $rtn    = intval($rst["CNT"]) > 0;
        self::closeCursor($stmt);
        return $rtn;
    }