External schema for topic map database

In order to cope with large-scale topic maps that store a lot of information, it is necessary to utilize topic map databases. Although, database management systems should provide users with external schema functions such as views, topic map databases do not have such functions. In this paper, we propose a method of implementing a view function, by focusing on the fact that the substructure of topic maps can be regarded as a topic map. In order to realize the idea, we developed an access control system based on the view function. Through an experiment to measure the execution time, we confirmed that these functions work correctly and have little effect on the execution time.