begin
 DBMS_SCHEDULER.DROP_JOB('job2');
 DBMS_SCHEDULER.CREATE_JOB
  (job_name => 'job2',
   job_type => 'PLSQL_BLOCK',
   job_action => 'begin
                  update country
                  set population = population + 1
                  where code=''CN'';
                  end;',
   auto_drop => FALSE,
   repeat_interval => 'FREQ = MINUTELY; INTERVAL = 2;
     BYSECOND = 5, 18, 31, 45, 51',
   start_date => SYSDATE+1/2880,  -- after 30 secs
   end_date => SYSDATE+11/1440, -- after 11 minutes
   enabled => TRUE);
end;
/
