First off, I'm trying to define database tables with attributes from Schema.org, eg., for example I have a table named "JobPosting" that more or less has the same attributes as those defined in <http://schema.org/JobPosting> (baseSalary, etc.,), same goes for another table named "Organisation"

I have recently come across dbpedia.org (<http://dbpedia.org/ontology/Organisation>), the schema details seem to be much more richer, but I'm am confused as to: 

1. Is dbpedia.org ontology an extension of those listed in schema.org?
2. Are dbpedia.org schemas recognized by major search engines (as those from schema.org)
3. What's the difference between Microdata and RFDs?

I'm going a little stir crazy trying to find the details...I couldn't find any comparisons vis-a-vis dbpedia.og vs schema.org.