Relationship models

[Darran Rolls <Darran.Rolls@Sun.COM>]

Folks

 

On the working group call today, we discussed relationships and decided (informally) that between now and next weeks committee con-call we should open up a discussion thread on modeling relationships in 2.0, then plan to summarize current thinking and next steps on the call Tuesday.  

 

To kick off this thread, I want to make a few open and leading statements on my (current) understanding of the objectives and issues around relationships in 2.0.

 

Objectives

 

1 - To provide within the protocol explicit support for expressing relationships between PSO's

 

2 - We will not be providing explicit support for expressing relationships between any other protocol or model elements - this would have to be done at the attribute level in target object schema

 

3 - To provide extensible support for the mechanics of expressing relationships without specifying definitive concrete models for specific relationships. That is to say, we will not be defining what a role, group or hierarchy actually means, although we should not do anything that prevents cooperation at this level via some form of optional binding or interface

 

4 - To allow the following relationship types to be expressed:

    4.1  Containment at the point of PSO creation and as an optional interface.  A sample containment relationship would be between and organization and its members

    4.2  Reference at the point of creation and as an optional interface.  A sample reference relationship would be a "created by" relationship between a

 

Leading Statements / Open Questions

 

1 - Relationships themselves are not defined as concrete objects in the 2.0 model, that is to say a relationship would not have a specific ID but would instead be the result of the connection between two or more PSO's that do have specific ID's

 

2 - Do we support multiple relationships between the same PSO's,  for example can a given PSO-ID be involved in more than one containment relationship and more than one reference relationship?