i agree if you disclose your certification
of course you will be discriminated. I have faced the same situation several times at an interview. The interviewer are well awared that you are certified he like to attacked you with dummy questions(not a professional one)..As an experience and certified oracle I personally feel unfair for myself and all of you as the whole. Most of older DBA are afraid of changing and new technology. They are way behind . Maybe aging factor is the cause!.yep my old boss is a good example.I think That is the reason you the certified is discriminated.