TRANSACTION MANAGEMENT IN DESIGN DATABASES

Databases are being increasing applied to support design and engineering, implemented on a backend file server and supporting shared access. A fundamental difference between traditional database management and design database management is that for most of the design process, integrity is partial A management scheme, called entity state transaction management, is proposed that deals with both the partial ordering of transactions and concurrency control over shared information resources. The techniques for automatic management of integrity are described in the light of the following problems: coordinating iterated partial analyses of an engineering system, propagation of design decisions in one subsystem to other subsystems and concurrent design operations within a single subsystem. The implications of entity state management for engineering database schema definition are also explored.