Re: Does LDAP support versioning of data?

["Kurt D. Zeilenga" <Kurt@OpenLDAP.org>]

LDAP provides entry level time stamping feature which most
servers implement.  Time stamping allows clients to detect
if the entry contents has changed.

LDAP versions schema elements.  In fact, each schema element
is identified by a unique global identifier known as an OID.
The specification of the element associated is not meant to
be altered.  Instead, a new specification published with its
own OID.

For example, if I had an object class defined as:
        ( 1.2.3 NAME 'foo' MAY 'cn' )
and I wanted to MUST cn, I could publish a new specification
as:
        ( 4.5.6 NAME 'bar' MUST 'cn' )

I would then have to recreate all my foo objects as bar
objects (by delete/add).  This is painful.  A better approach
would be instead define an auxiliary object class
        ( 7.8.9 NAME 'mustCNobject' AUXILIARY MUST 'cn' )
then add 'mustCNobject' to each of my foo objects' object
class attribute.

In small environments (ones in which you have complete control
of all uses of the directory), you *might* be able to cheat.
But this will depend upon your directory.  Some implementations
can be quite sensitive to inappropriate schema alterations.

Kurt

At 08:14 PM 9/17/00 -0700, mjc@home.com wrote:

>Hello,
>
>I am wondering if LDAP supports the versioning of directory sturctures
>(schemas) and the associated data. As an example, if I have a directory
>structure that looks a certain way one day, can I label the schema and its
>data as, say version 1.0. The next day I change my schema slightly, call
>it version 1.1 and then migrate as much of the data that I can from the
>version 1.0 directory to the version 1.1 directory?
>
>Anything close to that?
>
>If not, anyone know of other products that may?

LDAP isn't a product, it's a protocol.   Are there LDAP products
which support versioning as you describe?  Likely not.  Are
there non-LDAP products that support versioning as you describe?
Likely.

Kurt