Oracle Job Queue Coordinator (CJQ0) background process

The Job Queue Coordinator process checks the data dictionary (job table) for jobs to be scheduled. When necessary, CJQ0 creates a Job Queue Slave Process (Jnnn) which execute the job.

The job_queue_processes init parameter controls the maximum number of processes that will be created for job execution.

CJQ0 itself is started and stopped by scheduler.

There is one process per instance (also in RAC clusters).

CJQ0 is a background process.