Server Side Sorting control with multi-valued attributes

[Jim Sermersheim <JIMSE@novell.com>]

(Funny, as I was about to send this I see that Eric C. Hagberg just brought the same thing up so I guess this is just a further perspective)

I'm wondering if there has been or will be any more discussion on the subject of how to handle multi-valued attributes in a sorted search?

I see the second paragraph in section 4.2 of draft-ietf-ldapext-sorting-01.txt specifies the issue undefined.

We've been mulling over some ideas (I'll describe below) and I wonder if you're interested in modifying the SSS control to handle these ideas or not.  If not, we could propose a different draft (separate controls) which would modify behavior when performing a sorted search or vlv search.

Description:
Many client applications want to use the SSS control in order to obtain a sorted displayable list.  Since a sort key might represent a multi-valued attribute, the applications wish to include *each value*, in a sorted manner. 

Let's say a sorted list is to be created which displays *all* telephone numbers within an organization.  Since an entry could contain multiple telephone numbers, that entry would be duplicated in the list (new behavior).  In other words, each attribute value would have it's turn as the key

This new concept of duplicate entries is something the client application would be aware of and would be an option (per key probably).

The problem arises in trying to identify which attribute value to display.  We came up with several solutions.  One simple solution would be to return only the single value which is applicable to any instance of an entry as it is returned.  The drawback of course, is that a separate search operation must be executed later if the entire value set is needed.  Other solutions use various methods of identifying which values in which attributes are being used as the key in each instance of the entry.  These solutions tend to carry extra baggage and require extra processing.

Thanks.
Jim Sermersheim