Best option for Google App Engine Datastore and external database?

Question

I need to get an App Engine app talking to and sharing data with an external database,

The best option i can come up with is outputting the external database data to

Answer 1

You may want to consider exposing a set of web services on the external domain where your database is hosted, and then use the App Engine's URL Fetch API to communicate with your external domain via HTTPS.