server side sorting & paging?

[denis.havlik@t-mobile.at]

Let's look at a simple real-world use of LDAP directory: telephone book.

An electronic telephone book is an application that allows us to search for someone, and that also allows us to see the telephone book entries sorted by different criterias. Obviously we want to limit a number of entries per page too. With data in LDAP, it comes kind of natural to expect that server can return the results sorted and paged, so that client doesn't have to wait for all the results and sort them on its own. 

Thus we need:

1) Server Side Sorting
2) Paging.

I tried the google search on this, but the results are somewhat confusing - there are at least two ways how this could be done (VLV or server side sort + simple paged),  and apparently only simple paged has been implemented in openLDAP so far (in 2.2. branch). For more fun, neither VLV nor server side sort appear in the openLDAP roadmap.

On the other, getting 100.000 results from LDAP server, sorting them on the client, and then showing just a first 10 to users is so ugly an idea that i can't believe it.

Now I wonder if I'm overseeing something really obvious, i.e. some alternative way of getting just the fifth page of the telephone book from LDAP server and showing it to the user....

Could someone pls. explain me what's wrong with the idea of LDAP server returning sorted&paged results? 

thx
        Denis
--
T-Mobile Austria GmbH,
Information Technologies / Services
Knowledge Management & Process Automation

Dr. Denis Havlik,                                   eMail: denis.havlik@t-mobile.at
Rennweg 97-99, BT2E0304031        Phone: +43-1-79-585/6237           
A-1030 Vienna                                        Fax:      +43-1-79-585/6584