Protocols

You must specify "Objects=T" in the xa_open string if you want to use the AQ OCI interface. This forces XA to initialize the client side cache in Objects mode. You do not need to do this if you plan to use AQ through PL/SQL wrappers from OCI or Pro*C. The LOB memory management concepts you picked up from the Pro* documentation is not relevant for AQ raw messages because AQ provides a simple RAW buffer abstraction (although they are stored as LOBs).

You must use AQ navigation option carefully when you are using AQ from XA. XA cancels cursor fetch state after an xa_end. Hence, if you want to continue dequeuing between services (such as xa_start/xa_end boundaries) you must reset the dequeue position by using the FIRST_MESSAGE navigation option. Otherwise, you will get an ORA-25237 (navigation used out of sequence).