fixed data造句

in rtbac, users execute permissions to access fixed data and tasks to access flowing and varying data such as documents being approving . rtbac can renew authorization in time according to the flowing and use of data in workflow systems . a formal description and an analysis of rtbac are given
并且在rtbac中：针对工作流的静态特性：固定不变的数据如已经归档的公文不能进行修改、制发等操作，一般只能查看，故与存取权限相关，用户通过执行相应的存取权限才能访问，即传统的rbac模型；针对工作流的动态特性：正在流动、不断变化的数据如正在接受审批的公文则与任务相关，任务可以对此数据进行某种方式的存取。
It's difficult to find fixed data in a sentence. 用fixed data造句挺难的