Really thank you very much for your advice. Your advices are very helpful and informative.

It seems that Oracle 8i or 9i are voted (few ppl vote for other database). Here is the summary -
8i:
Adv: some companies still use 8i
Disadv: need to take 6 exam in total if I want to get the 9i cert as well.

9i:
Adv: only requires 4 exams to get OCP
Disadv: not backward compatible, ie. can't get back the 8i cert.

Anymore advices? I still can't make the decision.


For 9i, I have a great problem. I DON'T have 9i installation CD (Enterprise Edition).
However, I have 8i CD to be installed in my home PC for practice. Does this will affect my exam a lot if can't practice at home?