IIRC back-mdb needs export / re-import to make the OID change.
Why would back-mdb require an export/import for an OID change in the schema? OpenLDAP does not store the OID internally in the binary databases.
--Quanah -- Quanah Gibson-Mount Product Architect Symas Corporation Packaged, certified, and supported LDAP solutions powered by OpenLDAP: <http://www.symas.com>