title: Checklist for Database Schema Upgrades
body: <p>Having to upgrade a database schema makes installing a new release of software a lot trickier.  What are the best practices for doing this?</p>
  
  <p>I'm looking for a checklist or timeline of action items, such as</p>
  
  <ul>
  <li>8:30 shut down apps</li>
  <li>8:45 modify schema</li>
  <li>9:15 install new apps</li>
  <li>9:30 restart db</li>
  </ul>
  
  <p>etc, showing how to minimize risk and downtime.  Issues such as</p>
  
  <ul>
  <li>backing out of the upgrade if things go awry</li>
  <li>minimizing impact to existing apps</li>
  <li>"hot" updates while the database is running</li>
  <li>promoting from dev to test to production servers</li>
  </ul>
  
  <p>are especially of interest.</p>