title: Cross-version compatibility of Berkley DB files
body: <p>Legacy app uses Berkeley DB 4.8.
  Due to some reasons app has been compiled with newer Berkeley DB lib (I want to use 5.1 or 6.1).</p>
  
  <p>Whether the new app still compatible with the database files generated by old version of the app?
  If not - where I can find info about compatibility of different versions of the lib and database files?</p>