The magistrate shall conduct a preliminary examination unless the same is waived by the defendant. At such preliminary examination, the magistrate shall first read the complaint to the defendant unless the defendant waives such reading, and it shall be the duty of the magistrate at such examination to determine whether or not a public offense has been committed and whether or not there is probable or sufficient cause to believe that the defendant committed such public offense. Once commenced, the examination must be completed at one (1) session unless the magistrate for good cause shown by court order postpones it, or unless the parties stipulate in writing or upon the court record to a continuance to a date certain. If the defendant is incarcerated, the postponement or continuance cannot be for more than six (6) days or, if the defendant is not incarcerated, for more than twenty (20) days, unless on motion by or with the consent of the defendant the court orders a longer continuance or postponement.