ORA-39079: unable to enqueue message DG,KUPC in EXPDP datapump backup

Error

ORA-39065: unexpected master process exception in KUPC$QUEUE_INT.PUT_STATUS
ORA-39079: unable to enqueue message DG,KUPC$S_2_20090927001645,MCP, ,1,Y
ORA-06512: at "SYS.DBMS_SYS_ERROR", line 86
ORA-06512: at "SYS.KUPC$QUE_INT", line 924
ORA-25306: Cannot connect to buffered queue's owner instance


Cause
AQ_TM_PROCESSES parameter is having value zero.

Solution
Advanced Queueing is needed to set the value instead of Zero. AQ_TM_PROCESSES parameter must have a value > 0 otherwise you will get the above error.

1. Check the parameter value AQ_TM_PROCESSES

SQL> show parameter AQ

NAME                TYPE        VALUE
------------------- --------- ------
aq_tm_processes     integer     0

2. Change the value of aq_tm_processes parameter.

ALTER SYSTEM SET AQ_TM_PROCESSES = 1 scope=both;


3. Check the EXPDP backup now.