title: How important is it to select the smallest possible data type when designing a database?
body: <p>How much of a difference does using <code>tinyint</code> or <code>smallint</code> (when applicable) instead of just <code>int</code> do? Or restricting a <code>char</code> field to the minimum characters needed?</p>
  
  <p>Do these choices affect performance or just allocated space?</p>