Episode 5: ORACLE8 Backup and Recovery Workshop

"To impress your superiors..."

That's how one of the questions started on the ORACLE8 Backup and Recovery Workshop test, my fifth and final installment of the Oracle8 OCP DBA track. In order to fairly gauge the meaning of "OCP certified" on DBA resumes, and as part of the background for my Advisory Board work on behalf of the Database Domain, I am going back through the DBA certification process.

Why on earth would you perform backups "to impress your superiors?" I thought it was part of the job description. This test suffers from the same problems the others do: just when you think it's going to cover lots of relevant examples, you hit a run of questions designed solely to test your memorized knowledge of obscure syntax. In this test, that syntax includes coverage of RMAN - a tool I've never had more than 5 people in any of my presentations say they rely on. And then there are the marketing questions...

But rather than bemoan the tests, let's talk about how to pass them. First, find out how many questions you have to get right in order to pass the test - in general, it's about 70% (this information is available on Oracle's web site and on several certification prep sites). For a 60-question test, 70% means you need to get 42 right. To give yourself a little comfort, shoot for at least a 48 (80%). (On at least one test, the passing score is above a 48).

Of the 60 questions, 8 to 10 of them will be obscure syntax related questions designed to make you miss. There's really no other valid reason to ask these questions. A quick example: which command would you use to change certain init.ora parameters while the database is up, given a list of nearly identical commands? Answer: it doesn't really matter - if you guess wrong the first time (in real life), you'll do a quick edit, put the right one in, and run it. That requires the ability to learn from your mistakes and quickly adapt to changing conditions - critical skills for a DBA but not for this test.

So up to 10 of the questions, right off the bat, are toss-ups. Since they're multiple choice, figure you get 2 of those right. So far, that's 8 questions missed, leaving 52. Of the rest, say you know 36 well enough to be confident. That leaves 16 questions, and your score is already 38. If you guess randomly, you should get four of the remaining 16 questions correct, getting a passing score. If you get 10 of those 16 right, you get your 48.

All of this is based on getting 36 questions right out of 60, and guessing at a 25% clip on the remaining questions. Some of the questions have multiple answers to select, so you'll need to do no worse than 25% on those. A good solid grounding in concepts is required to pass, but still that's just a 60% (36 out of 60). If you can eliminate all but two answers on the 40% you don't know (including the toss-ups), your score should be 36+12 = 48.

For other tests, the passing score may be higher, but the basic approach holds: Identify and score well on the ones you know, and aim to beat the statistical average on the ones you don't. If you know your material well - that is, if you know the basic syntax options, and have used them in practice - you should be able to get the 60% score that forms the basis of this strategy. When evaluating the certification claims of others, you know that they knew at least 60% of the material covered, but you'll have no idea what they missed or how well they guessed. It's an imperfect measure until a more suitable test is devised.

Five for five, recertified.

Oh wait, I almost forgot: