Object flavor evolution in an object-oriented database system

The ability to gracefully accommodate dynamic evolution is essential in data-intensive office information systems. Among the wide spectrum of kinds of conceptual database modification, there is an important subkind which involves changes to the fundamental semantics of objects, vis-a-vis their nature as symbolic, abstract, type (set), relationship (mapping), or behavioral (procedure). This kind of change is termed “object flavor evolution”. For example, a real-world concept modelled in a database as a symbolic object (e.g., a string denoting the name of a person) may later evolve to or be alternatively viewed as an abstract object (e.g., a person entity). This paper examines object flavor evolution in the context of a simple, extensible object-oriented database model; this model is the kernel of an experimental prototype system termed PKM (for “personal knowledge manager”) currently under development. The PKM object-oriented modelling constructs and operations are presented, along with a description and analysis of specific kinds of object flavor evolution.