Does Pellet support incremental reasoning?
Incremental reasoning means the ability of the reasoner to process updates (additions or removals) applied to an ontology without having to perform all the reasoning steps from scratch. Pellet supports two different incremental reasoning techniques: incremental consistency checking and incremental classification. These techniques are applicable under different conditions and provide benefits for different use cases.
Incremental Classification
Incremental classification is used to update classification results incrementally when the class hierarchy changes. This feature is enabled by utilizing module extraction feature provided in Pellet. The first time an ontology is classified, Pellet also computes modules for each class. Initial classification and module extraction can be performed in serial or in parallel. When the ontology is changed in a way that affects the class hierarchy, Pellet will determine which module is affected and the reclassify only that module which is typically much smaller than the original ontology.
Incremental classification is most suitable for cases where the ontology contains a large and/or complex class hierarchy. It is not intended to improve instance reasoning and the benefits of incremental classification are minimized when the ontology uses enumerated classes.
Incremental classification is accessible only through OWLAPI interface via a specialized reasoner interface. This reasoner interface only supports queries about classes and not instance related queries. See IncrementalClassifierExample in the Pellet distribution for details. Incremental classifier is robust, well-tested, and suitable for production systems.
Incremental Consistency Checking
Incremental consistency checking is used to update consistency checking results incrementally when the instance data changes. The only changes it supports are addition or removals of instance assertions. If the ontology is changed by adding new class or property axioms, incremental consistency checking will not be used. It is also not used if the ontology contains enumerations, inverse properties, or rules.
Incremental consistency checking is most suitable for cases when consistency checking takes a lot of time or there are very frequent changes to the instance data. It is not intended to improve classification time.
This feature is accessible both from Jena and OWLAPI interfaces. It is disabled default and needs to be enabled manually. See IncrementalConsistencyExample in the Pellet distribution for details. Incremental classifier is robust, well-tested, and suitable for production systems. Incremental consistency checking is not robust, not well-tested, and not suitable for production systems.
