Job not starts at the scheduled time

[DDDDBA]

We use DBMS_JOB to schedule our daily job but it is not always starts at the scheduled time, sometime starts after 2 hours, sometime even after 8 hours too.

My question is, how to make sure it starts every day @13.00 Hrs. Any help is appreciated.

Here is my code:

DECLARE
X NUMBER;
BEGIN
SYS.DBMS_JOB.SUBMIT
( job => X
,what => 'JOBPROCESSING ;
'
,next_date => to_date('17/03/2009 13:00:00','dd/mm/yyyy hh24:mi:ss')
,interval => 'TRUNC(SYSDATE)+1+13/24'
,no_parse => FALSE
);
SYS.DBMS_OUTPUT.PUT_LINE('Job Number is: ' || to_char(x));
COMMIT;
END;
/

[davey23uk]

is the job still running?

[DDDDBA]

Yes, Job is running every day but some days it will not start @13.00, not sure why. I want to ensure it starts always @13.00 every day..

[davey23uk]

no, is the job still running by the time the next day comes round

[ales]

Check the job_queue_processes parameter. If the value is too low there might be no free process to run the job at the desired time. Use the dba_jobs_running view to see running jobs.