Is specialized for navigation data, and does not support common data source operations such as sorting, filtering, paging, caching, or data record operations such as updates, insertions or deletions.

• 专用于导航数据,并且不支持排序、筛选、分页或缓存之类的常规数据源操作,也不支持更新、插入或删除之类的数据记录操作。