The ExternalObject class provides a superclass for all external class subclasses and defines the behavior specific to external proxy classes. The query engine uses the ExternalObject class at run time to populate virtual proxy instances. Each external class contains the SQL query required to populate a class extent or to do a join query for a single valued reference.
For details about the methods defined in the ExternalObject class, see "ExternalObject Methods", in the following subsection.
External database-defined and user-defined external object subclasses