I have a book for the current 1Z0-047. I don't know if they still have the 9i exam.
The book is: OCA Oracle Database SQL Certified Expert Exam Guide. By O'Hearn. You can purchase on amazon.
I sat for the exam once and failed. It was the most difficult certification exam I have ever taken. There are a majority of questions that the multiple choice answers are exactly the same except for placement of parenthesis or the use of aliases or table names. I am scheduled to retake next month.
I have found the
test exam sold with the book and the test exam sold by selftestsoftware.com are pretty similar in style to the questions on the real exam.