Accession Number:

ADA275048

Title:

The Covering Property of the Object-Oriented Data Model - Design and Implementation Issues

Descriptive Note:

Master's thesis,

Corporate Author:

NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s):

Report Date:

1993-09-01

Pagination or Media Count:

119.0

Abstract:

Inheritance is a necessary condition for construction of an object- oriented data model OODM, but it is not sufficient. This is because inheritance applies to only one hierarchy. The covering construct meets this deficiency because covering maps an object in one hierarchy to a class of objects in another hierarchy. To date, covering has not been implemented into an existing OODM application. This thesis implements the covering construct into a functioning object-oriented database environment. Implementation was achieved through modification of data constructs and the creation of a user-defined relation linking two or more hierarchies. Using the Multi-model Multi-lingual Database Supercomputer MDBS, a sample, working application is described illustrating real world applications. The results of this thesis show that the covering property can be implemented into an existing OODM without sacrificing the integrity of the data model. The cross-hierarchical mapping afforded by covering is a powerful construct that expands the capabilities of the model beyond pure inheritance. This makes the OODM suitable for a far wider range of applications. Together, inheritance and covering meet the necessary and sufficient conditions of the OODM. Object-oriented, Object-oriented data model, Covering, Aggregation, Inheritance, Hierarchical data model.

Subject Categories:

  • Computer Programming and Software
  • Computer Systems

Distribution Statement:

APPROVED FOR PUBLIC RELEASE