Multiple Class Objects

Object-oriented databases, Multiple Class Object

The object-oriented database model is not standardized till this time. Very
important theme is the multiple inheritance. But using of the persistent objects
playing more roles during their lifetime time extends this topics toward the
multiple class objects. It is difficult to define the semantics of the multiple
class object especially in the part of virtual methods. For the standard multiple
inheritance it is defined, which of the virtual method implementation is actual
in every time and the implementation conflicts can be checked during the compile
time. For the multiple class objects the rules for the definition of actual
implementation are not defined. Moreover, the necessary checking leads to the
time consuming run time algorithms. This paper tries to define rules for the
multiple class objects, which make it easier to select an actual implementation
of virtual methods and make possible checking during the changing of the object
types.