title: Sql Server 2008 Update query is taking so much time
body: <p>I have a table name <code>Companies</code> with <code>372370</code> records. </p>
  
  <p>And there is only one row which has <code>CustomerNo = 'YP20324'</code>. </p>
  
  <p>I an running following query and its taking so much time I waited 5 minutes and it was still running. I couldn't figure out where is the problem. </p>
  
  <pre><code>UPDATE Companies SET UserDefined3 = 'Unzustellbar 13.08.2012' WHERE CustomerNo = 'YP20324'
  </code></pre>