A model of collaborative systems transactions

In collaborative systems, a group of users engage in common tasks such as group decision making, office information system and collaborative writing. Multiple users can modify the shared information resources concurrently in these systems, and the update may affect the tasks in which other users are simultaneously engaged. Change notification mechanisms are important for the concurrency of the collaborative systems. Furthermore, there are two types of propagation of change results according to the collaborative relationship among the users (i.e. intermediate results and final results), distinguishing the layer of propagation is necessary. We present a model of collaborative systems transactions that support two-layer change notification to deal with it. The proposed model is developed under our prototype object oriented database management system called XDOODB