Rolling the inheritance structure down into the subclass (Storage Mapper)

UML Modeling Techniques > Data modeling > Storage Mapper > References > Rolling the inheritance structure down into the subclass (Storage Mapper)

Each subclass maps to a table. Each superclass is rolled down and the generalized attributes from the superclass are replicated in each of the subclass tables. This is a useful approach if the superclass has few attributes and there are many subclasses, or if the subclasses have many attributes.