No judgment shall be a lien as against a purchaser of real estate for valuable consideration without notice, unless it be docketed according to the fifth section of this article, in the county wherein such real estate is, before a deed therefor to such purchaser is delivered for record to the clerk of the county court of such county; nor shall such judgment, though it be docketed as aforesaid, be a lien, after ten years from its date as against such a purchaser who purchases after such ten years, unless within such ten years an execution shall have issued on such judgment and such execution or a copy thereof be filed in the office of such clerk, or, unless such purchaser have actual notice of the fact that such execution was issued, though it was not so filed; nor shall such judgment, though it be docketed as aforesaid, and though one or more executions shall have issued thereon and shall have been filed as aforesaid, be a lien, after ten years from the date of the last execution so filed, as against such a purchaser who purchases after such ten years, unless such purchaser have notice of the issuing of an execution within ten years preceding the date of such purchase.