Re: Attribute subtyping, clarification request

["Kurt D. Zeilenga" <Kurt@OpenLDAP.org>]

At 05:33 PM 5/19/2005, Rici Lake wrote:
>While we're on the subject of attributes and attribute subtypes:
>
>If I understand correctly, displayName;lang-de is a subtype of displayName,
>rather than an instance of it, so that it would be possible to have several displayName assertions, each one in a different language, without violating the single-value property of the attribute type.

The displayName;lang-de attribute description is a subtype
of the displayName attribute description, both of which
name distinct attributes in a directory object.

>It should also be possible to have displayName;lang-fr;lang-es if the spanish and french names were identical, right?

Correct.

>But then the rules don't seem to prevent the above from being combined with displayName;lang-fr and displayName;lang-es as individual assertions, in which case a search requesting the displayName;lang-es attribute type would actually (surprisingly) return two assertions. Or am I missing something?

Not sure I am parsing this correctly, but basically,
        displayName;lang-es;lang-fr is a subtype of
                displayName;lang-es
                displayName;lang-fr
                displayName

So, if (displayName;lang-es;lang-fr=*) is TRUE then logically
(displayName;lang-es=*), (displayName;lang-fr=*) and
(displayName=*) would also be TRUE.  And displayName;lang-es;lang-fr 
may be returned if the client requested any of the attribute
descriptions listed above (or all user attributes).

See [Models] for a discussion of the subtyping hierarchy.

Kurt