Cooperative Object Buffer Management in the Advanced Information Management Prototype

In the CAD, CAM. and Robotics environment the on-line construction and manipulation of data ob’ects is very often done at dedicated workstations rather than at h ost systems. As the storage space of workstations is usually not that large and as large designs are also not performed by a single designer but by a group of designers, in general, one would like to use host database systems as central servers to store, to retrieve, and to “communicate” data objects. Current database management systems, however, have mainly been designed for business administration purposes where much simpler structured data objects occur. But even if the server database system offers adequate complex object support, the question remains how workstation and server database system should work together. That is, how the changes pcrformcd at the workstation should be communicated back to the Server such that a new version of an object can be created at the host site in an eflicicnt and storage saving way. In this oaocr the aopreach implemented in the Advance2 Information ‘Managemcht Prototype (AIM-P) at the IBM lleidelberg Scientific Center is described. The AIM-P database managcmcnt system is based on NIT2 (Non First Normal Form) relations and follows the stratczv of a ’ multi-level cooperation]communication bctwccn wo& station and scrvcr database system in order to rcducc redundant work at both sides as much as possible.