title: How to make SQLAlchemy in Tornado to be async?
body: <p>How to make <code>SQLAlchemy</code> in <code>Tornado</code> to be <code>async</code> ?
  I found example for MongoDB on <a href="http://emptysquare.net/blog/refactoring-tornado-code-with-gen-engine/">async mongo example</a> but I couldn't find anything like <code>motor</code> for <code>SQLAlchemy</code>. Does anyone know how to make <code>SQLAlchemy</code> queries to execute with <code>tornado.gen</code> ( I am using <code>MySQL</code> below <code>SQLAlchemy</code>, at the moment my handlers reads from database and return result, I would like to make this async).</p>