What are Android application update issues and best practices?
<p>I've published an Android applications on the Android market and now have an update to do.</p>

<p>I want to know if any of you have already done that, and what experience can you share about it :</p>

<ul>
<li>How to manage version conflicts ?</li>
<li>What to do with databases ?</li>
<li>Can you make appear a message with "what's new" if it's an update, but nothing it's a new installation ?</li>
<li>Should you backup old data before updating, and how ?</li>
<li>Did you run into any trouble and how did you solve it ?</li>
<li>Can update be partial (like, just a patch) ?</li>
</ul>

<p>Any advice is welcome.</p>
