Cal. Civ. Proc. Code § 683.040

If the judgment creditor applies for a writ for the enforcement of a judgment and the application is made more than 10 years after the date the judgment was entered or renewed, the application shall be accompanied by an affidavit of a person having knowledge of the facts stating facts showing that the issuance of the writ sought in the application is not barred under this chapter. A copy of the affidavit shall be attached to the writ when issued.