What doors does having the certification open for you?
A lot but I'm currently not taking advantage of it. I'm pretty sure if I send my resume w/ this cert, I'll probably get a job within few days. The reason I'm not taking advantage is that I'm trying to find Hadoop project within my company. No, I don't want to quit my company due to how wonderful they treat me ^_^
How long did it take you, including study time and actual exam time?
Hm.. in terms of study / coding time, I've spent about 80 hours. Coding in Hadoop is super easy but understanding how it really works is damn hard. In order to have good code design, developer needs to understand how it works. I only study from 1 book. It's called Hadoop Definitive Guide 3rd edition. Need to end-to-end with this thing.. the book is awesome but I've had to read several times and google to truly understand. The exam is about 90 min but I completed in 45 min. It's 60 question and you need to answer at least 40 to pass. I barely passed... I had 45/60. Lots of tricky questions.