Rich Base Schema
Sangwon Lee, Hyoung-Joo Kim · Journal of Database Management · 2000
In this paper, we propose a model of schema versions for object-oriented databases called RiBS. At the heart of this model is the concept of the Rich Base Schema (RiBS). Each schema version is in the form of a class hierarchy view over one base schema, RiBS, which accumulates all the schema information ever defined in the schema versions. Users, insulated from RiBS layer, access databases only through schema versions. Users impose schema evolution directly on schema versions, and the effects are, if necessary, automatically propagated to RiBS. We first describe the structure of the model and then introduce a set of invariants that should be satisfied by the model structure. As the third element of our model, we give a set of schema update operations, of which semantics are defined so as to preserve all the invariants.