title: How to limit number of updating documents in mongodb
body: <p>How to implement somethings similar to <code>db.collection.find().limit(10)</code> but while updating documents?</p>
  
  <p>Now I'm using something really crappy like getting documents with <code>db.collection.find().limit()</code> and then updating them.</p>
  
  <p>In general I wanna to return given number of records and change one field in each of them.</p>
  
  <p>Thanks.</p>