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Re: About aliases an X.500....
NDS implements aliases in such a way that the naming rule for the alias is _identical_ to the naming rule that applies to the referenced object. For instance, it seems meaningless to us to allow an alias which points to a Person thing to use anything other than the same naming attributes as that person. Ditto containment (can't put a alias to a Person in places you couldn't put the person in the first place). Similarly, of course, you can't "cast" a Person into a Server by changing the ObjectClasses list for the alias...the alias reflects exactly what is defined on the instance of the object to which it points.
I agree that aliases can be useful in constructing alternative namespace hierarchies for browsing or even searching. But it makes my head hurt thinking too much about changing the object class types, naming rules, or containment rules which govern aliases to be different from the objects to which they refer.
Ed
-------------------
Ed Reed, Technologist
Group Technology Office
Novell, Inc.
+1 801 861 3320
>>> Harald Tveit Alvestrand <Harald.Alvestrand@maxware.no> 04/07/1998 01:13:39 >>>
Alan,
on a completely different topic:
I've thought for a long time that using aliases is the only way
one can sensibly use the distinguished name for uniqueness and for
search scope limitation at the same time.
I think I have also got a fairly solid gut feeling for how it's being used
(basically adding empty records of type "alias", with only the naming
attribute; assuming that searches follow aliases encountered in a
subtree traversal unless the appropriate control is invoked).
But I was trying to find supporting text for this picture in the X.500
series when I came across this entry in X.501(93) 12.3.3:
>NOTE - The object class alias does not specify appropriate attribute types
>for the RDN of an alias entry. Administrative Authorities may specify
>subclasses of the class alias which specify useful attribute types for RDNs
>of alias entries.
Put this together with the fact that X.520 does not mention aliasing,
and that naming rules don't seem to give either permission or restriction
on the use of RDNs for aliases, and it seems to me that the standard and
its usage is somewhat underspecified.
I see two possibilities:
- The industry has ignored naming rules where aliases are concerned, and
is buliding products that "allow anything".
- The industry is shipping private schemas that specify rules for how one
can use aliases, but these are not standardized.
Obviously, software developed to the two paradigms above will not necessarily
interoperate.
Can you help me understand this one?
Regards,
Harald T. Alvestrand
--
Harald Tveit Alvestrand, Maxware, Norway
Harald.Alvestrand@maxware.no