Hi Hari,
As far as I know we cover everything you'll need to know for the exam. We are fortunate because we led the team that created the exam. This means that we have a really good idea what's in the exam.
Our goal is to cover 110% of what's on the exam. Many other authors who write mock exam questions need to cover more like 130% of what's on the exam just to be sure they don't leave anything out. This means that you'll often find discussions of mock questions that cover topics that aren't on the actual exam. Of course it's really good to know as much
Java as possible, so learning that extra 20% is a good thing, but strictly speaking for the exam it's not necessary.
Of course we have to also keep in mind that Kathy and I make our share of mistakes! It's certainly possible that we failed to completely cover a topic, and we're always watching this forum, so that if someone finds something missing, and explains it here we can update the book. I can tell you that when we updated the book for the
SCJP 6 exam we added coverage of a handful of small topics that JavaRanchers helped us to discover we hadn't covered well enough in the SCJP 5 book.
hth,
Bert