Dynamic class hierarchy management for multi-version ontology-based personalization

• We study multi-version ontology-based personalization in large resource collections.
• We show how to store a multi-version ontology class hierarchy in a temporal relation.
• Both tree-shaped and general graph ontologies are considered.
• Algorithms to efficiently support ontology evolution are presented.
• We show how multi-version ontology-based personalization queries can be supported.

We introduce a storage scheme that allows the representation and management of the evolving hierarchical structure of a multi-version ontology in a temporal relational database. The proposed scheme is aimed at supporting ontology-based personalization and temporal access to large collections of resources (data, documents, procedures etc.) stored in a dynamic environment. Whereas in previous works we considered tree-shaped ontologies only, in this work we consider ontologies with a class hierarchy structured as a general directed graph, that is also supporting multiple inheritance and intersection classes. We will also show how multi-version ontologies must be dealt with for the processing of ontology-based personalization queries.