A PilotCard-based shared hypermedia system supporting shared and private databases

Abstract

We developed a Pilot Card-based shared hypermedia system supporting a shared databwe and a number of private databases. By integrating a layered architectural object-oriented database with PilotCard mechanisms, we realized a shared hypermedia system in which individual users can maintain private data in their own private workstation and use the shared data in a remote workstation. Furthermore, we extend the concept of a version-derivation hierarchy to cope with the requirements of multi-user environments. In the system, the versions of an object can be physically dispersed over both personal layers and the common layer; the system combines the versions stored in the personal layer with different versions in the common layer. Moreover, a user can attach PilotCards to any data as annotations and create associative hypertext-links between related data. Since PilotCards attached to shared data are invisible to any other user, the user can add hisfher personal view to the shared data layer without disturbing other members.