When IBM employees have a question about certification for DB2 for Linux, UNIX, or Windows, there's only one man they call. He's not in New York. He doesn't even work for IBM. He lives in the other hyphenated town in North Carolina (Fuquay-Varina, pop. 39,042), and his name is Roger E. Sanders.
In his day job, he's a consultant corporate systems engineer with EMC Corporation; he looks for ways to improve how DB2 works with his company's storage technology, including improvements in virtualization and disk-based replication. His most recent book (his 21st on DB2 and his 9th on DB2 certification) is DB2 9.7 for Linux, UNIX, and Windows Database Administration: Certification Study Notes (MC Press Online, 2011).
And since 2002, he has helped IBM develop 17 DB2 certification exams, more than any other individual. Want to know why certification is important? Roger Sanders is the man to ask. We talked to him about how the tests are put together, how they can help a DBA's career, and—oh yes—about the certification test he failed.
Q: How did you get started with DB2 certification?
Sanders: My background is a little unusual. I started out as a chemist and kind of backed into computers. I was laid off in 1992 and ended up getting a job designing DB2 applications. That was when DB2 was the Database Manager part of OS/2 1.3 Extended Edition. I saw how lacking the documentation was for the product, so I decided to write a book that would help other developers build applications that interfaced with DB2 databases [The Developer's Handbook to DB2 for Common Servers, McGraw-Hill, 1999]. Eventually, I wrote four more books on database application development, including one on ODBC [Open Database Connectivity]. Then, my publisher [McGraw-Hill] asked me to write a certification study guide for DB2 7. So I contacted Susan Visser, who was the DB2 certification program manager at the time, and she got me involved in the exam development process.
Q: And you do this in addition to your EMC work?
Sanders: Yes. As an EMC employee, I am required to create and meet a set of quarterly goals, and one of my goals involves being active in the industry, which includes publishing and public speaking. The column I write for IBM Data Management magazine, the speaking and training I provide at conferences, and the certification work I perform all feed into that goal. My being an expert on DB2 makes EMC customers feel confident about the information I provide on using EMC technology with DB2 databases.
Q: Why is certification important?
Sanders: There's a big debate about who's a better DBA: one who is certified or one who's been doing the job for 20 years, but has no certifications. Both can be equally good, but the individual who makes the effort to get certified will be forced to learn new things. And if you are constantly learning new things, you're improving your skill set.
Certification drags you out of your comfort zone. Let's say you're a DBA—your job is to keep the company database up and running, to do performance tuning, and to oversee backup and recovery. You're comfortable performing these tasks because you do them on a day-to-day basis. But to get certified, you have to know a broad spectrum of things, and some of these things will involve activities you don't do on a daily basis. For instance, you may rarely, if ever, be required to analyze the access plans for SQL statements. But to pass a certification exam, you're going to have to know how to generate and analyze an access plan because you're going to be tested on it.
Plus, the technology changes every 18 to 24 months, and to take advantage of new features and functionality that gets introduced with each technology refresh, you have to keep up. Certification forces you to stay current. For example, in the DB2 8.1 Family Fundamentals exam, there was a section on data placement, and there weren't any questions on row decompression in that section because that technology did not exist in version 8. However, in the DB2 9 Family Fundamentals exam, there are questions on deep compression in the same section because deep compression is a feature that was introduced with version 9. Conversely, future exams will no longer have questions about the Control Center, because Optim Data Studio is replacing it. If you don't pursue certification, it's like getting a degree in computer science and then not taking any additional training after you graduate. What you've learned becomes stagnant.
Q: What kinds of DBAs take certification tests?
Sanders: All kinds. It's not just someone who's had a lot of hands-on experience with databases. It's someone who is intellectually curious. It's also someone who enjoys learning about the new features and functionality that are provided with each release of DB2, and who is looking at ways to incorporate those features in their own database environments. Deep compression is just one example—IBM introduced deep compression in DB2 9, but in order to use it you had to know how to enable it and how to build a compression dictionary. Plus, only tables could be compressed. In DB2 9.5, automatic dictionary creation was added so you no longer had to deal with building a dictionary yourself; in DB2 9.7, indexes and temporary tables can now be compressed. All of this results in a savings in storage costs and, in many cases, improved performance. If I were still a DBA, I would be investigating how I could put that technology to use in my company. And I probably would have become familiar with it by preparing for a certification exam.
Q: How much do certifications help when someone is looking for a job?
Sanders: Some hiring managers do look for certifications. (I was such a manager; certification was something I always looked for on resumes and asked questions about in interviews.) It takes away the guesswork when they're looking at someone who is otherwise an unknown entity. If applicants have certifications, it shows that they have some level of skill and knowledge needed to perform the job. When I got my first DB2 certification, I did so because I wanted to show my manager and any potential future employers that IBM thought I knew enough about DB2 application development to let me use their certification logo.
In terms of bringing value to a new job, having certifications in related areas can help a hiring manager get a feel for the depth and breadth of an individual's knowledge. For example, if you are a certified DB2 DBA and you have been certified on SAN [storage area network] and NAS [network attached storage] technology, a hiring manager can see that you have skills and knowledge that will allow you to help them deploy a large-scale data warehouse on an EMC storage array—and that may be just the set of skills they are looking for.
How certification tests get created
Q: How many people does it take to put together a certification test?
Sanders: Usually, about ten to twelve people, communicating via conference calls and live meeting sessions. Most are subject matter experts [SMEs] with IBM. Others are working DBAs, consultants, or members of the International DB2 Users Group [IDUG]. Each must specialize in some area related to DB2. Not everyone, including me, is an expert on everything.
Q: Walk us through the process of creating a certification test?
Sanders: We start by building an exam blueprint, or outline. This is done by asking what the important topics are that a person at a particular certification level needs to know. For example, the DB2 Fundamentals exam tests a candidate's knowledge of security; creating and working with tables, indexes, and views; using SQL; and isolation levels and locking. The DB2 DBA exam focuses more on utilities, high availability, and performance monitoring. The Advanced DBA exam gets into federated databases, partitioning, materialized query tables, and multidimensional clustering tables.
After we develop a list of topics, we decide how many questions are needed for each topic and at what level of difficulty these questions should be. Once we have captured this information in the blueprint, each SME identifies the topics they feel comfortable writing questions for and the DB2 certification program manager makes writing assignments; everyone writes the same number of questions, but only for the topics they know best. We then separate for about three weeks to work on our writing assignments—it takes me anywhere from one to three hours to write a single test question, and I usually end up writing between 14 to 24 questions for a new exam, so three weeks is an appropriate amount of time. After everyone has completed their writing assignments, we get back together as a group and examine each question thoroughly to determine its validity, to make sure the correct answer indicated is indeed the correct answer, and to make sure none of the wrong answers are valid or are easy to identify as being wrong.
One thing that's very important to note: we must provide a citation for every question we write. We need to source exactly where in the technical documentation the answer appears, so that if anyone challenges the validity of the exam, its validity will stand up in court. A lot of times, I will write CLP [Command Line Processor] scripts to test my questions and answers, and these scripts are submitted along with my questions to serve as supporting material for the exam.
When we have completed the question review process, we perform what is known as an Angoff analysis to determine the passing score. Here, each SME goes through the entire test and identifies how many “minimally acceptable candidates” out of 100 candidates they believe will be able to answer each question correctly. The DB2 certification program manager combines the results of this analysis and determines the passing score, based on averages.
Q: You also work on the practice exams?
Sanders: That's right. When we write questions for the certification exams, we also write practice questions. As we do the question-by-question analysis, some of the really easy questions and some of the really difficult ones may end up on the practice exam so that the actual exams themselves are more evenly balanced. You can access the practice exams at www-03.ibm.com/certify. You don't get the answers to the questions, but you do get a grade that gives you a sense of whether you're ready to take the actual certification exam.
In my certification exam study guides, I try to create practice questions that are as close to the real exam questions as possible. For example, where an exam question might say, “Which of the following is …,” I'll write a question that says, “Which of the following is NOT…,” and include the actual answer in the list of answers provided. So when someone sits down to take the actual test after reading my book, they're familiar with the format and the wording of both the questions and the answers. And they have seen, in a different form, what they will need to know to pass the exam.
Q: How do you determine the level of difficulty for each question?
Sanders: The group establishes at the outset what skills we think someone at a particular level should possess. Then we adjust the difficulty by how we phrase the questions. You don't want a question whose answer is glaringly obvious, and you don't want a question on something that's so obscure that a test candidate would normally look it up in the documentation if they needed to use it.
A simple question might be a memory recall question, such as, “Which two communication protocols does DB2 support?” A more difficult question might have an exhibit to analyze or a scenario to work through. For instance, we might show output from a DB2 configuration file and ask, “What will happen when the current transaction log file becomes full?” To answer such a question correctly, you must know how to interpret the output shown and you must understand how DB2 logging works. The difficulty is really controlled in the wording of the question and the complexity of the exhibit or scenario.
In each case, as you develop a particular question, it's important to think about what a minimally acceptable candidate should know. For example, when we developed the DB2 9 Family Fundamentals exam, we knew we needed to test on XML because pureXML was such a big part of the version 9 release. However, XML is more important to developers than it is to DBAs. So, the questions on XML were relatively easy and there weren't very many of them—that way, if a candidate didn't know much about XML, they wouldn't be penalized if they were unable to answer the questions correctly.
Q: Just out of curiosity, have you ever failed a certification test?
Sanders: Yes. The very first time I went to take a DB2 certification exam, I was at an IDUG conference in Dallas where I also happened to be speaking for the very first time—and, at that time, I was terrified of public speaking. For some reason, I decided to take a DB2 6.1 Application Developer certification exam about an hour before I was scheduled to speak. Big mistake. I was too nervous to concentrate and I failed—by just one question. I gave my presentation, went by the bookstore and spent a few minutes reviewing a copy of one of my books on DB2 application development, and went back and took the exam again. This time I passed. To this day, I share that story with my students when I teach a DB2 DBA Certification Exam Crammer course and I tell them there's no shame in failing an exam. Just go back and study the areas you're weak in and try again. I've taken other certification exams over the years that I did not pass the first time. But I learned something every time I prepared for an exam, and to me, that's one of the best things about certification. It's a learning process.
- Read more articles in IBM Data magazine.
- Download an evaluation copy of DB2 for Linux, UNIX, and Windows.
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