The first thing you need to know is what jobs are scheduled and enabled. To do this we simply query the dba_scheduler_jobs view as follows:

SELECT owner, job_name, enabled FROM dba_scheduler_jobs;

Now we know what jobs are present and enabled/ disabled we can use the DBMS_SCHEDULER to change their status. The DBMS_SCHEDULER is a package which provides a collection of scheduling functions and procedures and in our case since we wish to either disable or enable a job, we simply call its Disable or Enable procedure as follows:

begin
DBMS_SCHEDULER.disable (name => 'STS.STS_OVERNIGHT_REFRESH_JOB');
end;

After you have run the PL/SQL batch to disable or enable the desired job, another check of the dba_scheduler_jobs view will prove that the job state is as you expect.

Enjoy!