i have got my oca last year and my ocp just last month, utilizing these two books and the ocp 10g all-in-one exam guide from john & damir. these two books have a quite complete coverage of the materials in oca and ocp 10g exams, which means it sometimes covers more than needed to pass the exam. in one way it is good for our knowledge, but it sometimes could be frustating because of the long chapters (need two books to pass ocp instead of one book with john/damir book). i would suggest however to still get the john/damir book in addition to this one to pass the oca/ocp exam (like i did), for the sake of completeness and chapter organizations. these two books have rather unique chapter structures (not aligned with oracle admin I and admin II training materials), for instance there are three chapters in the admin II training that combined into one chapter of the second book. overall it is still a good reference not just for 10g oca/ocp exam, but also for your oracle 10g knowledge in general.