RFC 1804 (rfc1804) - Page 3 of 10


Schema Publishing in X



Alternative Format: Original Text Document



RFC 1804          Schema Publishing in X.500 Directory         June 1995


   In this document we concentrate on the aspect of schema
   access/retrieval from the directory. Since schema objects are defined
   and employed, the modification , addition and deletion of schema
   objects can be carried out using existing directory mechanisms. But
   the operational issue of synchronizing the schema with the DIB will
   require further attention.  Similarly the issue of schema propagation
   requires further work and is outside the scope of this document.  The
   strategy proposed in this document has a very simple and workable
   approach.  No added DAP/DSP functionality is envisaged. At the same
   time by using the directory's distributed framework scalability
   problems are avoided.  In essence, it allows the distributed storage
   of schema objects and proposes a naming scheme which allows
   algorithmic schema retrieval. Of course, on the down side, more than
   one directory read operation may be required to retrieve the
   information about an object and its attributes, as objects and
   attributes are stored as separate entries in the directory.

   As schema information of all objects in a naming context are stored
   below the root entry of that naming context, the same DSA will be
   able to supply the schema information stored in that DSA. Thus there
   is no need to contact another DSA for resolving the schema of an
   object stored in the local DSA.

3. Storage of Schema Information in the Directory

   The schema information may be stored and distributed using mechanisms
   external to the X.500 directory standard [5]. This document proposes
   storing schema information in the directory.  It has the following
   advantages:

        o The components of the directory can access the schema
          information using the standard directory protocols.

        o The nature of the directory naturally allows the schema
          to be distributed. Schema used locally can be kept in the
          local DSA itself whereas schema for general objects like
          person, organization etc can be made available to all
          components of the directory by publishing it.

   In the operational model, the schema information in the directory is
   expected to complement the schema information held in central
   repositories.









Mansfield, et al              Experimental