I was involved in a discussion on LinkedIn about the proper timing for an Oracle PL/SQL developer to take the 1Z0-146: Oracle Database 11g: Advanced PL/SQL exam. One of the posters was indicating that while it was appropriate for people new to PL/SQL to study for and take the earlier exam: 1Z0-144: Oracle Database 11g: Program with PL/SQL, they should wait until they have some job experience before taking the 146 exam to earn the Oracle Advanced PL/SQL Developer Certified Professional credential. My own opinion is that waiting until you have a few years of experience is not a bad idea, but it is certainly not something that is necessary for everyone.
The difference between our positions lies in how I view Oracle certifications, their relationship to Oracle knowledge/expertise and (as the title suggests) the causality between the two. Causality is an uncommon word -- even for native English speakers (unless you happen to be a theoretical physicist). Basically it refers to cause and effect. The 'effect' that I am referring to this case is getting employers to recognize you as being knowledgeable about Oracle PL/SQL. There is a widespread belief that earning a given certification will cause employers to view you as being skilled with Oracle.
It does not work that way in the real world. I have interviewed people for Oracle positions many times over the years. I can tell you that I do not automatically assume that because someone has earned a certification that they have all of the relevant skills. A certification means that someone may have a certain set of knowledge. During the interview, I will generally ask questions related to their certifications to get a feel for whether they do or not. If a candidate has the Advanced PL/SQL certification and their resume shows a previous job developing PL/SQL, I will be more likely to believe that they are knowledgeable of the language. I will still ask the candidate several questions to verify that to my satisfaction, however.
Employers cannot trust certifications by themselves because there are too many people who focus on the piece of paper. Their goal is passing the exam rather than learning the information being tested. In researching my study guides I run across brain dump sites all the time. Even people who do not cheat with brain dumps may simply memorize enough facts to pass the exam without actually understanding the material being tested. To be fair, I do not completely trust job experience either. It is possible to be PL/SQL developer for several years and still be really bad at it. I know this is true -- I have worked with some of them.
So... if certifications are not the cause for employers viewing an individual as being knowledgeable about Oracle PL/SQL, then what is? Well -- not to put to fine a point on it, but the cause is becoming knowledgeable about Oracle PL/SQL and being able to demonstrate that knowledge. Candidates should take the time to really learn all of the information being tested in the 1Z0-144 and 1Z0-146 exams. Practice writing PL/SQL blocks. Read tutorials and articles from some of the masters like Steven Feuerstein.This will give you a core of knowledge about the language even if you have no job experience using it. In an interview, you will be able to demonstrate this knowledge when asked questions and that will generate the desired effect.
My approach to certifications is therefore that they should be used as a road map for becoming more knowledgeable. The focus is not on 'passing the test' but rather on 'learning the information'. Focusing on the test is what leads to brain dumps and other cheats. This is counterproductive. If you get hired on the basis of knowledge you do not possess, it will rapidly become obvious. After you pass the exams, keep reading and practicing and learning. In the IT industry, the more you know, the more valuable you are. As a fresher, that knowledge will help you to sit an interview with more confidence that whatever question is asked, you will be able to answer it. Your increased confidence and your knowledge will both do much more to land the job than any piece of paper.