Deleting All entries in the Google Datastore locally

The Google Server (App Engine), simulates the development server on the local machine using a file called as local_db.bin in the WEB-INF/appengine-generated/ directory. (It is not uploaded with your application.)


http://code.google.com/intl/fr/appengine/docs/java/tools/devserver.html#Using_the_Datastore

To delete all entries, stop the server, delete this file and then Start the server again.