Hi! My name is Dimitri. I wrote a book to teach SQL to developers. Check it out! is available on its website. I have been using and contributing to Open Source Software for the best of the last twenty years. I took role as developer, maintainer, packager, release manager, software architect, database architect and administrator, sometimes devops. In the same time frame I also have started several companies (they are still thriving) with a strong Open Source business model, and I have been in manager positions at times too, including at the Executive level in big companies. ©