Change the period of a job

Question

If I change the period of a job at runtime, how this job will be scheduled?
If this job is idle when I change its period. If the idle time has been larger than new period, will this job be invoked as soon as I set the new period?
If the idle time is still smaller than the new period, will this job be invoked in a time of (new_period - idle_time)?
I want to know the details of the transitional duration. THANKS A LOT :)

Answer 1

Hi,
Here are some answers . I have also included a test case below which is trivial enough that you should verify this for yourself.
If this job is idle when I change its period. If the idle time has been larger than new period, will this job be invoked as soon as I set the new period?It won't run immediately but it will run at its next scheduled time i.e. after a time less than the new_period - see test case below, but wait more than 2 minutes before doing set_attribute.
If the idle time is still smaller than the new period, will this job be invoked in a time of (new_period - idle_time)?Yes it will - see test case below, but wait less than 2 minutes before doing set_attribute.
I want to know the details of the transitional duration. As soon as you do a set_attribute the scheduler recalculates the next_run_date of the job and it will run at that date.
Here is the test case. How long you wait before doing the set_attribute determines whether you are testing case #1 or case #2.
grant create job to scott;
connect scott/tiger
-- test updating repeat_interval while job is enabled
begin
  dbms_scheduler.create_job('j1',
    job_type=>'plsql_block', job_action=>'null;',
    repeat_interval=>'freq=hourly',enabled=>true);
end;
-- wait a few seconds for the job to run
select job_name, state, run_count, last_start_date, next_run_date
  from user_scheduler_jobs ;
-- wait less than 2 minutes or more than 2 minutes
begin
  dbms_scheduler.set_attribute('j1','repeat_interval','freq=minutely;interval=2');
end;
select job_name, state, run_count, last_start_date, next_run_date
  from user_scheduler_jobs ;Hope this helps,
Ravi.