I have some experience with Oracle before, I resigned and passed all 5 exam with 90 days, today i am OCP 8i DBA now! Happy to share my experience as following:
I can measure the difficulty of all five exams with learning period, as following:
No ITEMS period pass score/my score/total Payment
1 IZO-023: 24 days 42/42/60 60$
2 IZO-025: 17 days 42/44/60 290RMB
3 IZO-026: 11 days 41/42/57 290RMB
4 IZO-024: 20 days 42/44/57 600RMB
5 IZO-001: 7 days 39/53/57 600RMB
-- 023 is the hardest, i just pass the exam, too dangerous!
-- 024 is hard to learn, and easier to exam. Too many virture table and tuning skill to understand. Some table have taken me 5 times to learn. So boring and detail!
-- 025 i prepared sufficiently, go through the experiment with 2~3 times(Just following the text book, not the experiment at the end of book). Although the score is bad, i have learned the backup and recovery skill yet.
-- 026: some one said it is easy, but not to me. Becacuse not succefully going thought the experiment following the book, i lost a lot of questions about them at the end of serval paragraphs. My lucky has override my shortage, if i lose the exam, ... ..., nightmare! So,Be careful!
-- 001: It is the most easy one, even easier than 029 of MCSD. If you have done STS for 2 times, you can pass it easily.
Saving the easiest for last, Best choise of course!
For the payment, you can ask for paying with US$60 without any off. I am lucky to attend the hot test in shanghai on Sept. 26~27. So the payment of my two exam is 290RMB, so greate! Although Oracle sales the exam with 542 RMB now in beijing, I am in Shanghai ,and have to pay some aditional fee for commission charge and courier fee, therefor i payed 600RMB for the last two exams.
Thank you for your patient to look!