From numerous postings on Oracle certification forums and on LinkedIn groups, it appears to me that there is a common misconception about the Oracle Expert certifications. It seems many people feel that if you study for and pass one of these exams that you become an expert on the topic -- even if you had little or no knowledge prior to your exam preparation. This is simply not true. The study process no more makes you an instant expert than reading a medical textbook and putting on scrubs and a mask would instantly make you a surgeon.
Just to be clear -- I really like Oracle's expert series. I hold the expert certifications for Application Express, SQL, and SQL Tuning. I enjoy the fact that the topics are covered in greater depth than is typical for OCA and OCP level exams. In addition, they are some of the hardest Oracle exams I have ever taken, which pushes me to work harder when preparing. That said, I have been writing and tuning SQL for over seventeen years and programming in Apex since it was HTMLDB. I was an expert in these topics before taking the tests. I did not pursue the certifications in order to become an expert but rather to refine and expand what I already knew from having worked with them for years.
It is possible to pass the Application Express expert certification while having no aptitude whatsoever at creating a web application using that environment. The exam cannot test someone's ability to program and does not attempt to. Instead it tests the candidate's knowledge of the development environment. That said, studying for the exam was valuable for me as an experienced developer because it forced me to learn portions of the interface that I had previously not made use of.
The same holds true for the SQL and SQL Tuning exams. People with little or no experience of Oracle SQL will not instantly become skilled at writing or tuning it simply by studying the exam topics. The expert exams are designed to help experienced Oracle professionals to backfill any knowledge gaps and enhance their skills. They are not designed as a shortcut for freshers to prove that they are knowledgeable.
One of the biggest pitfalls with inexperienced professionals gaining expert certifications is that it can set them up to fail. Going back to the earlier 'surgeon' analogy. You memorized the textbook, you look great in scrubs, and you somehow convinced a hospital to hire you as a surgeon. This is great -- who needs medical school or years in a residency program? However, sooner or later someone is going to expect you to be able to perform surgery...
In the real world, it would never get that far, of course. Someone pretending to be a surgeon would almost certainly get caught early in the hiring process. Likewise, someone portraying themselves with Oracle expertise that they do not really have is almost certain to be tripped up during the interview. Misrepresenting yourself is likely to result in your resume being tossed in the trash. Your best bet is to pursue certifications that are appropriate to your level of Oracle proficiency.