The db4o generator currently supports two different generation modes namely:

• generating a class based hierarchy
• using interfaces and corresponding to model the class hierarchy of the owl ontology.

As db4o handles classes as special objects and only allows Query by Example on java classes only, the first approach has been added to offer this feature.

Class Based Generation

For the class based generation the limitations for Owl2Jena also apply. Also, the following limitations are present due to the class based inheritance tree:

• No support for mulitple inheritance. UnionClasses and IntersectionClasses are not supported. Neither are unions or intersections as property range definitions.
• No support for nested property structures. All properties are handled as default properties.

Interface Based Generation

For the interface based generation the limitations for Owl2Jena apply.

Currently not implemented