The Unified Extensional Versioning Model
U. Asklund, L. Bendix, H. Christensen, and B. Magnusson
In Proceedings of SCM-9, Ninth International Symposium on System
Configuration Management, J. Estublier (Ed.), Toulouse, France, September
1999. LNCS, Springer Verlag.
To appear.
Abstract
Versioning of components in a system is a well-researched field where various
adequate techniques have already been established. In this paper, we look
at how versioning can be extended to cover also the structural aspects
of a system. There exist two basic techniques for versioning - intentional
and extensional - and we propose a unified extensional versioning model
for versioning of both components and structure in the same way. The unified
model is described in detail and three different policies that can be implemented
on top of the general model are exemplified/illustrated by three prototype
tools constructed by the authors. The model is analysed with respect to
the number of versions and configurations it generates and has to manage.
Finally, the unified extensional model is compared to more traditional
intentional models on some important parameters. The conclusions are that
the unified model is indeed viable. It not only provides the functionality
offered by the intentional model with respect to flexibility during development
and management of combinatoric complexity, but also offers a framework
for management of configurations that enables systems to provide much more
advanced support than is commonly available.