1. A method of operating a computer system that provides an object-oriented programming environment, having one or more datastores that contain record-oriented data files, and communicating with one or more users executing object-oriented application programs for manipulation of persistent data objects corresponding to the data files, the method comprising the steps of: (a) receiving a request for manipulation of a persistent data object from one of at least two incompatible persistent object service systems utilizing different data protocols and class hierarchies; (b) associating each persistent data object with a data file by (1) associating each instance of a persistent data object with a persistent object identifier; (2) associating each instance of the persistent data object with only one data file in a datastore, such that each instance of an attribute of the data object is mapped to one associated data file, and (3) defining within each persistent object identifier a data identifier that is associated with either a record number or a key within the data file associated with the persistent object identifier; and (c) instructing the datastore to alter the information within a selected data file through the associated instance of the persistent data object.