Altering JOB_QUEUE_PROCESSES

Question

Does altering the JOB_QUEUE_PROCESSES to 0 on an Oracle DB block the Oracle jobs from being scheduled too?

I found in http://download-west.oracle.com/docs/cd/A97630_01/server.920/a96521/jobq.htm some information about it, principally, the following:

The JOB_QUEUE_PROCESSES initialization parameter controls whether a coordinator job queue process is started by an instance. If this parameter is set to 0, no coordinator job queue process is started at database startup, and consequently no job queue jobs are executed. The JOB_QUEUE_PROCESSES initialization parameter also specifies the maximum number of Jnnn processes that can concurrently run on an instance. The maximum number of processes that can be specified is 1000.

However, I am uncertain what the "coordinator job queue" represents in the grand scheme of things.

Thank you very much in advance for your timely responses.

Answer 1

Prior to 11.2, if you set JOB_QUEUE_PROCESSES to 0, no job scheduled via DBMS_JOB will be executed. That parameter does not affect jobs scheduled via the DBMS_SCHEDULER package. If by "Oracle jobs" you are referring to things like the background job in 10g and later that automatically gathers statistics on objects with missing or stale statistics, those are DBMS_SCHEDULER jobs that would be unaffected by JOB_QUEUE_PROCESSES.

Starting in 11.2, that changed and JOB_QUEUE_PROCESSES began to affect DBMS_SECHEDULER. The default value also changed from 0 to 1000 and it was made a non-basic initialization parameter.