Oracle scheduler interval time

Question

I have a question regarding the Oracle Jobs.

If I have a Job defined to be executed every 5s, but if for any reason there is a Job that last 6s. What will be the consequences ?

for instance:

BEGIN
DBMS_SCHEDULER.CREATE_JOB (
   job_name             => 'oe.my_job1',
   job_type             => 'PLSQL_BLOCK',
   job_action           => 'BEGIN DBMS_STATS.GATHER_TABLE_STATS(''oe'',
                            ''sales''); END;',
   start_date           => '15-JUL-08 1.00.00AM US/Pacific',
   repeat_interval      => 'FREQ=SECONDLY;INTERVAL=5', 
   end_date             => '15-SEP-08 1.00.00AM US/Pacific',
   enabled              =>  TRUE,
   comments             => 'Gather table statistics');
END;
/

i) 2 Jobs executing at the same time ???

ii) A job FIFO queue ??

Is there a way to tell the job to be executed only if no job of the same action is running at that moment ????

Answer 1

from the docs: https://docs.oracle.com/cd/B28359_01/server.111/b28310/scheduse004.htm#ADMIN10040

Immediately after a job is started, the repeat_interval is evaluated to determine the next scheduled execution time of the job. It is possible that the next scheduled execution time arrives while the job is still running. A new instance of the job, however, will not be started until the current one completes.