Using a relational database as an index to a distributed object database in engineering design systems

A description is given of a pragmatic architecture for engineering design systems that divides the databases of those systems into a relational database and an object-oriented database. In the architecture, the relational database is used to find designs in the object database, and the object database is used to support the concurrent editing of designs by multiple users and processes on networks of workstations. The architecture has the advantage of allowing the relational database to concentrate on providing fast indexing methods to find designs, and allowing the object database to concentrate on providing good concurrency and version control tools for design editing. The authors describe the two-part architecture, give classifications for the types of data that can be extracted from the object database and put into the relational database, and give formulas that can be used to quantify the size of the relational database.<>