As noted in
MB-45967, there is a need to further disambiguate 12009 error returned by Query into  retriable-transient-errors (NMVB, ENOMEM, ETMPFAIL etc) and  non-retriable-specific-errors (duplicate-key, key-not-found etc.) and set 'retriable' flag on lcb error code for . Query Team mentioned 'cause' string returned with 12009 can be used for disambiguation. This will help applications/eventing decide whether to retry a failed operation or not.