时间标记在实体和元组级上，空间数据采用非拓扑数据模型。

Finally, the time is signed on entity and record, and non-topological data model is adopted to organize spatial data.

youdao

时间标记在实体和元组级上，空间数据采用非拓扑数据模型。

Finally, the time is signed on entity and record, and non-topological data model is adopted to organize spatial data.

youdao