public static function getIndexOrderList() { if (!self::$orderFields) { self::$orderFields = array('metadata.CREATED_AT' => 'created_at', 'metadata.UPDATED_AT' => 'updated_at', 'metadata.VERSION' => 'version', 'metadata.METADATA_PROFILE_VERSION' => 'metadata_profile_version', 'metadata.OBJECT_TYPE' => 'object_type'); } return self::$orderFields; }