I will just tread lightly here until I am sure what's missing and what's just hidden.

What is the location for contacts database and SMS database?

I have to confess I have not paid much attention to tracker before. I still do not understand the real reason for it... so many application seem to depend on it.
I kind of get it's usefulness on indexing music/videos/pictures, but why on earth do things like contacts depend on it??