1. A method of responding to a query from an application to a temporal relational database implemented on a computer apparatus, the method comprising: receiving the query at the temporal relational database, the query corresponding to a point in time for which the temporal relational database should be reconstituted; using a class loader, retrieving, from the temporal relational database, a class definition representing a structure of the temporal relational database that is appropriate for the query that is being performed at a point in time that the class definition is requested by the query; compiling the class definition into a format readable by the application upon every change to the temporal relational database schema; storing the compiled class definition as an attribute value in the temporal relational database, the value being stored with a full temporal history; and sending the class definition to the application, wherein the application utilizes the class definition for the point in time to perform the query of the temporal relational database responsive to the point in time.