Integrity Constraints for Hyperlinks in a Hypermedia Database System: AYATORI

摘要

Internet users have become well acquainted with the World Wide Web (WWW) system, and WWW has be- come the most significant service on the Internet. In the near future, the importance of large scale hypermedia database sys- tems based on WWW technologies is expected to continue to increace. The present study focuses on the issue of managing hy- perlink integrity constraints on WWW like hypermedia database systems. After formally defining path existence constraint defi- nitions (PEDs) using intuitive examples, we apply the notion of PEDs to represent hyperlink integrity constraints. Intuitively, a PED can be used to represent the following integrity constraint. If a reference path exists in a given database, then another cor- responding reference path must also exist. An outline of a proto- type hypermedia database system, AYATORI, which is based on the proposed model and under development, is also mentioned.