Different candidates have different experiences. Nevertheless, there exists some conventional wisdom on the subject. Compared to other database vendors' exams, the questions on the DB2 tests are difficult. But as Table 2 shows, the percentage of questions you need to answer correctly to pass is quite low. Experience at IDUG conferences indicates a pass rate of about 75% for DB2 exams. Remember that all questions are multiple choice, so answer every one (there is no penalty for wrong answers, so at least guess at every question). The exam software allows you to mark questions to return to later, so you can skip hard questions and return to them.
The time allowed for the exams is generous. You'll only consume the allotted time if you check your work carefully. When you're done with the exam, click the Done button and the software instantly shows you whether you passed. You can print copies of your score on the spot via the LAN-attached printer. If you pass, IBM sends you a certificate via mail for printing and framing. You may also request one by mail.
What if you do not finish the test in the allotted time? The screen freezes, a message tells you the exam has ended, and you'll see the same pass or fail message you would if you had clicked the Done button yourself. Oops!
You must study for the exams. Being a DB2 guru won't help if you don't study! The tests are broader than most IT pros' knowledge base and also very specific in what they ask. They are designed to be rigorous.
Compared to competing database vendors' exams, the IBM DB2 tests seem to have fewer overly specific trivial pursuit questions and more questions requiring deep thought. The exams are intended to test your DB2 knowledge and ability to figure out DB2 problems (not just your ability to memorize what's in the certification study guides). My feeling is that they achieve this a little better than competitors' tests. Be prepared to stay cool while facing some tough questions. Remain secure in the knowledge you'll only need a low percentage of questions answered correctly to pass.
Useful background information on certification is freely available at Certification Magazine's Web site and Cramsession.com. You can always seek technical help while you study in discussion forums at DBAZine, Database Journal, IDUG's Web site, the IBM DB2 Developer Domain, DBForums.com , and Database Toolbox. These are great resources, with tons of technical articles and active online communities from which to learn.