code: func GetDDLJobs(txn kv.Transaction) ([]*model.Job, error) {
  	t := meta.NewMeta(txn)
  	generalJobs, err := getDDLJobsInQueue(t, meta.DefaultJobListKey)
  	if err != nil {
  		return nil, errors.Trace(err)
  	}
  	addIdxJobs, err := getDDLJobsInQueue(t, meta.AddIndexJobListKey)
  	if err != nil {
  		return nil, errors.Trace(err)
  	}
  	jobs := append(generalJobs, addIdxJobs...)
  	sort.Sort(jobArray(jobs))
  	return jobs, nil
  }
docs: // GetDDLJobs get all DDL jobs and sorts jobs by job.ID.