title: Mysql phpmyadmin show empty cardinality
body: <p>Why does phpMyAdmin show an empty cardinality?
  <a href="https://i.stack.imgur.com/bq9sv.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/bq9sv.png" alt="enter image description here"></a></p>
  
  <p>If I edit the index (without change anything) and save, the cardinality will appear, but after a TRUNCATE and some INSERTs, the cardinality become empty again.</p>
  
  <p>Running</p>
  
  <pre><code>ALTER TABLE tableName ENABLE KEYS
  </code></pre>
  
  <p>doesn't help.</p>
  
  <p>How to make the cardinality always present?</p>
  
  <p><b>Edit:</b></p>
  
  <p>The phpMyAdmin version is 4.6.4</p>
  
  <p>The MySql version is libmysql - mysqlnd 5.0.12-dev - 20150407</p>
  
  <p>The Engine is MyISAM</p>