Total street names

The object class contains all current street names and their history at the time of warehouse creation. The data base for the city of Chemnitz takes into account the following definitions for the award of street names or road keys and for the management of the street name history: Each road key is unique within the entire database, i.e. it exists to a road key either a current or historical object. The relation of the indication under “from date” to the current date determines whether a street name is current or historical. If a street is given again under an equal name, it bears a new key. The road key may not be changed if it has been assigned for a street name once. The road key thus represents a unique key in the database. It can be used directly from the address warehouse to determine the street name without having to pay attention to the current or historical condition of the street name.该对象类涵盖当前所有街道名称及其在数据仓库创建时的历史沿革信息。开姆尼茨市的数据库针对街道名称命名、道路标识（road key）的赋予以及街道名称历史的管理，制定了如下定义：每条道路标识在整个数据库中均具有唯一性，即每一条道路标识均对应唯一的当前或历史街道对象。通过“起始日期”字段的标注与当前日期的关联关系，可判定该街道名称处于生效状态还是历史状态。若某条街道复用了相同的名称，则会被分配新的道路标识。道路标识一旦被赋予某一街道名称，便不得进行修改。因此，道路标识是数据库中的唯一主键，可直接从地址仓库中调取以获取街道名称，无需考虑该街道名称当前或历史的状态。