protected function assembleIndexKey($index_cols,$table_name) {
		if (!is_array($index_cols))
			$index_cols = array($index_cols);
		$name = $table_name.'___'.implode('__', $index_cols);
		if (strlen($name)>64)
			$name=$table_name.'___'.\Base::instance()->hash(implode('__', $index_cols));
		if (strlen($name)>64)
			$name='___'.\Base::instance()->hash($table_name.'___'.implode('__', $index_cols));
		return $name;
	}