if (schema.existsClass(OUser.CLASS_NAME))
schema.dropClass(OUser.CLASS_NAME);
if (schema.existsClass(ORole.CLASS_NAME))
schema.dropClass(ORole.CLASS_NAME);
if (schema.existsClass(OSecurityShared.RESTRICTED_CLASSNAME))
schema.dropClass(OSecurityShared.RESTRICTED_CLASSNAME);
if (schema.existsClass(OFunction.CLASS_NAME))
schema.dropClass(OFunction.CLASS_NAME);
if (schema.existsClass(OMVRBTreeRIDProvider.PERSISTENT_CLASS_NAME))
schema.dropClass(OMVRBTreeRIDProvider.PERSISTENT_CLASS_NAME);
if (schema.existsClass(OClassTrigger.CLASSNAME))