The district attorney has the power, in his discretion, to dismiss an indictment or a count in an indictment, and in order to exercise that power it is not necessary that he obtain consent of the court. The dismissal may be made orally by the district attorney in open court, or by a written statement of the dismissal signed by the district attorney and filed with the clerk of court. The clerk of court shall cause the dismissal to be entered on the minutes of the court.