Abstract: The present invention is applied to a map database apparatus, where: a road is represented as a link string in which a plurality of links, each of which has nodes at both ends thereof, are connected; and a plurality of link string data, each of which includes node information relating to the node and is respectively provided for each of levels which correspond to different scale maps with regard to an identical link string, are stored. And a link of a lower level which has a larger scale, the link being common to a link of a upper level which has a smaller scale, has a link identifying data which is common to a link identifying data of the common link of the upper level.

Abstract: In a method for managing design data regarding an electronic circuit in order to design and analyze the electronic circuit, the design data is arranged according to a hierarchical-layer module structure. The design data in each of hierarchical layers of the hierarchical-layer module structure is divided into objects. The objects together for each of the hierarchical layers are connected together and the objects are connected together over the hierarchical layers. The design data including design data having different items and design data having different data lengths is integrally managed.