This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
They're completely different, unrelated products. Their similarities are that they're relational database that implement SQL, and that JDBC drivers are available for both. Their full feature lists can be found on their respective web sites.