raphael.ouazana@linagora.com wrote:

This is a little bit like shooting himself in the foot: a/ Create a new attribute with back-config b/ Create a second new attribute which inherits from the first one with back-config c/ Remove the first attribute with back-config d/ OpenLDAP does not complain. But when you restart the server, you get an error message.

It boils down to that back-config should not allow to remove schema elements which are somewhere used. In this context "used" means 1. referenced in another schema element or 2. used in an entry in one of the database backends. While 1. could be easily checked by slapd thinking about 2. leads to the conclusion that schema elements should not be removable at all.

There's a possibility to mark schema elements as OBSOLETE. This is what I consider best practice. Also it still keeps the old OID reserved. (My web2ldap displays OBSOLETE schema elements as struck out in the schema viewer so one can easily notice whether there are OBSOLETE attribute types referenced e.g. in an active object class.)

Ciao, Michael.