Re: Nested SearchRequests

There is interest in developing query expression extensions for LDAP to allow
for more processing on the server side.  Most of the approaches are at the 
propose/research/expermiment state.  While the goal of reducing the amount of
round trips the client must perform is a good one, this topic has tended to 
lead to a number of questions, now all of which have yet been answered, such
as:
 1 how to perform these operations efficiently when more than one server holds
   the scope of the search?
 2 how to deal with arbitrary levels of recursion and identifying intermediate
   nodes (e.g. find all entries E1 which have an attribute A1 with a value 
   which point at entries E2 which have an attribute A2 with a value which point 
   at entries which have a value which points back at the same entry in E1,
   and return the entries which have any DN-valued attribute that points at 
   entries E2)
 3 how does this integrate with the work being done to have server-side 
   consistency checking (often called business rule logic) of adds and modifies
 4 how does a client interrogate the server to determine the kinds of more 
   advanced processing it can perform, and how would a client operate if 
   some but not all servers holding the DIT can perform this processing?

Traditional SQL based systems have focussed on 2, and while there has been 
research in RDBMS systems on 1 and 3 I do not yet believe we are yet ready to 
standardize on an approach for a distributed directory service based on LDAP.

Mark Wahl, Directory Product Architect
Innosoft International, Inc.