Heh, thx. After that test here conclusion was that I should check shredding more and otherwise I was pretty satisfy. I read the documentation a lot and all the recommended courses.
What I see is little tricky is that it does not seem to be “fully implemented”, I am a PL/SQL Developer and all the exam I took from Oracle has quite easy rule - if do not know. if it is logically possible, it is implemented and work as expected. With MongoDB I see that they are some things that we need to be familiar, that it is not there (likely yet). For example INDEX SKIP SCAN is something that is explicitly written that is not part of MongoDB.
One more question: There was some page / link how to check connection, do you know where is that? Is it possible to do before paying for the exam?