Roles:From objects, security and databases perspective

A role paradigm conformance model (RPCM) called Typehole model was developed and implemented in Java. It does not use Is-role-of inheritance and is free from the object schizophrenia (OS) problem (OSP). An extended distributed role model provides multifarious role hierarchies at different sites. Modeling object role systems is prone to OSP. OSP is the error in the RPCM design to subscribe to the viewpoints in the client space. OS and OSP are contrasted. A classification of OSPs is made. Role modeling problem is the requirement to design an OSP-free RPCM with Is-role-of inheritance. The existing object-oriented role models have been evaluated as regards OSP. No role model has strong claims as regards solving the role modeling problem. A security model was developed for RPCM-based distributed object systems and implemented on CORBA. By designing message filter hierarchies, hybrid security is developed at global and local levels for RPCM-based object systems. Role is either abstract or concrete as it can be a type or an instance. Copyright © 2005, American Association for Artificial Intelligence (www.aaai.org). All rights reserved.