Database XML field with constraints
<p>I'm doing an application, where I have customers that can require data extension in the database schema.</p>

<p>To do data extension I have a XML data field, where I store each customers extension.</p>

<pre><code>CustomerID |    Name   | XML field 
   1            Jack     &lt;Age&gt;24&lt;/Age&gt;
   2            Marie    &lt;Country&gt;Norway&lt;/Country&gt;
</code></pre>

<p>My question is, if Jack now wants his attribute Age to have a constraint NOT NULL, is this possible without affecting the other customers?  </p>

<p>My other question is, if Marie wants an index on attribute Country, is this possible without affecting the other customers? </p>