a. check if the object has nullified PK field
b. check if the object is already registered
c. lookup from cache and if not found, last option select on DB
*/
final PersistenceBroker pb = tx.getBroker();
boolean isNew = pb.serviceBrokerHelper().hasNullPKField(cld, obj);
if(!isNew)
{
// use method call to guaratee creation of oid
final Identity oid = getIdentity();
final ObjectEnvelope mod = tx.objectEnvelopeTable.getByIdentity(oid);