title: Slow foreach() for Column update
body: <p>I want to update a column of a table which got ~4k rows. The column has to get the date of the parent so I'm using a simple foreach:</p>
  
  <pre><code>Parent.VariableDate = DateTime.Now;
  foreach (var item in Parent.ChildList)
  {
      item.vari = Parent.VariableDate ;
  
  }
  </code></pre>
  
  <p><strong>Problem:</strong></p>
  
  <p>This action is taking ages. Can I immediately update a whole column? </p>