title: SQL Server 2005: Index bigger than data stored
body: <p>I created 1 database with 2 file groups: 1 primary and 1 index.</p>
  
  <ul>
  <li>Primary file group includes 1 data file (*.mdf): store all tables</li>
  <li>Index file group includes 1 index file (*.ndf): store all indexes</li>
  </ul>
  
  <p>Most of indexes are non-clustered indexes</p>
  
  <p>After a short time using the database, the data file is 2GB but the index file is 12 GB. I do not know what problem happened in my database.</p>
  
  <p>I have some questions:</p>
  
  <ol>
  <li>How do I reduce the size of the index file?</li>
  <li>How do I know what is stored in the index file?</li>
  <li>How do I trace all impacts to the index file?</li>
  <li>How do I limit size growing of index file?</li>
  </ol>