California Code, Code of Civil Procedure - CCP § 2029.650

(a) If a superior court issues an order granting, denying, or otherwise resolving a petition under Section 2029.600 or 2029.620, a person aggrieved by the order may petition the appropriate court of appeal for an extraordinary writ. No order or other action of a court under this article is appealable in this state.

(b) Pending its decision on the writ petition, the court of appeal may stay the order of the superior court, the discovery that is the subject of that order, or both.