Issue:
During an Oracle E-Business Suite (EBS) patching cycle, the Prepare phase was observed to be stuck and not progressing further.
The process continued to run without any visible error in the adop logs.
After investigation, it was identified that the database parameter job_queue_processes was set to 0, which caused all background job operations to be disabled — resulting in the Prepare phase hanging indefinitely.
Root Cause
The Prepare phase in Oracle EBS internally executes several background jobs for validation, dependency checks, and data consistency verification.
These jobs depend on Oracle background job queue processes (Jnnn) to execute successfully.
When the parameter job_queue_processes is set to 0, Oracle disables all background job queues.
This leads to:
- EBS concurrent programs and patching processes getting stuck
- Background DBMS jobs not executing
- Long-running “Prepare” or “Apply” phases
Check the parameter value in SQL*Plus:
SQL> sho parameter job;
NAME TYPE VALUE
——————————- ———– ——————————
job_queue_processes integer 0
max_datapump_jobs_per_pdb string 100
max_datapump_parallel_per_job string 50
Here, the parameter job_queue_processes is set to 0, which disables all job queue processes.
Solution:
Increase the parameter value to enable job queue processes.
Run the below command as a privileged user:
ALTER SYSTEM SET job_queue_processes = 10;
System altered.
Now verify the updated value:
SQL> sho parameter job;
NAME TYPE VALUE
——————————— ———– ——————————
job_queue_processes integer 10
max_datapump_jobs_per_pdb string 100
max_datapump_parallel_per_job string 50
Once the parameter was updated, the Prepare phase was re-run and it completed successfully.
