[openstack-dev] [Keystone] Domains, Projects, and Groups are all collections

Adam Young ayoung at redhat.com
Wed Jan 23 20:47:28 UTC 2013

On 01/23/2013 03:38 PM, David Chadwick wrote:
> On 23/01/2013 20:23, Adam Young wrote:
>> Users, Groups and projects are owned by a domain.  This is an attribute
>> hierarchy.
> this is not the type of hierarchy I was talking about. Attribute 
> hierarchies are object oriented hierarchies in which subtypes inherit 
> all the properties of the supertypes. So for example, the surname 
> attribute type is a subtype of the name attribute type.
> What you are talking about is a containment hierarchy, in which 
> domains contain projects, and projects contain users. A Venn diagram 
> can be used to nicely depict the containment hierarchy.
> regards
> David
Ah, yes, I see the distinction.  No, I was not talking about object 
hierarchies, just organizational hierarchies.

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