Management of Implicit Ontology Changes Generated by Non-conservative JSON Instance Updates in the τJOWL Environment

tauJOWL (Temporal OWL 2 from Temporal JSON) is a framework we proposed to allow users of Big Data projects to automatically create, with the closed world assumption (CWA), a temporal OWL 2 ontology from time-varying JSON-based Big Data. Such an ontology, providing the semantics to the data, facilitates complex tasks like Big Data querying, analytics and reasoning, in an environment that supports temporal versioning at both data instance and schema levels. Update operations on temporal JSON Big Data may not respect the JSON Schema associated to them, like renaming a JSON object or a JSON object member, or replacing the current value of an object member with a new one that is not conformant to its type as specified in the corresponding JSON Schema. These update operations are called “non-conservative updates” and require implicitJSON Schema changes to be performed so that they could be correctly executed. Such JSON Schema changes need then to be propagated to theOWL 2 ontology in order to maintain semantic alignment. To this purpose, in this paper, we propose an approach for automatic management of implicit OWL 2 ontology schema change operations that are generated by non-conservative updates to temporal JSON Big Data instances, in the tauJOWL framework.