Mazda equivalent of RealOEM.com? (extensive parts info database)
 

One of the things I miss about BMW ownership is being able to use RealOEM.com to look up part numbers, diagrams, parts info, etc. Y'all should check it out if you haven't seen it -- it's pretty intense. Not as good as a dealership parts department stuff, but about as close as the masses can get.

Is there an equivalent for Mazdas?

No, not really, however one of our moderators, Ash8, was a Mazda parts guy and has access to the full catalog. I believe there is a Q+A thread about part numbers around somewhere.