1. A computer implemented method of making a feature specifier that represents a feature, a feature corresponding to a set of topology elements in a topology data model that is defined in a relational database management system, the topology data model including a topology element table in the relational database management system having rows representing topology elements, and the method comprising: using at least one processor that is to perform a process, the process comprising: receiving a specification of the set of topology elements, wherein the specification includes at least spatial information that comprises geographic information of the feature, and at least a part of the set of topology elements belongs to the feature; determining a first row for each of one or more non-existing topology elements of the set of topology elements that do not exist in the topology element table; determining a second row in a relations table in the relational database management system, wherein the relation relates the first row to the feature specifier; providing the feature specifier to represent at least the one or more non-existing topology elements of the feature in the topology data model based at least in part upon the relations table and the topology element table; and organizing topology data including geographic data in the relational database management system into one or more additional features by using at least the feature specifier, which represents at least the one or more non-existing topology elements, without identification of the one or more non-existing topology elements pre-existing in the topology element table.