My last comp check on small stuff was a DH82(a) in 1958 so things may have changed a bit.
not in the practical flying sense, for sure....
Under the German version of the JAR-FCL you would have to do a flight check with an examiner, which could (would!) contain some oral questioning. Sit down with your friend or an instructor and review as much as possible about the present regs, etc.... it wouldn't do any harm to refresh a lot of that. There are no set hours of "training" you may need, which should ONLY be done with an instructor!! He then decides when he thinks your fit enough to face the exam. He will also be able to tell you what to expect.
Good luck!!
Westy