How to Stop the Job Scheduler

You can prevent the Job Scheduler from running at startup by

This method will not prevent the use of DBMS_SCHEDULER.RUN_JOB. If someone use DBMS_SCHEDULER.RUN_JOB, the job will execute regardless of the setting of the SCHEDULER_DISABLED attribute

If you want to also stop the jobs which is created by DMBS_JOBS, you need to issue: