title: Time required to list off keys in a B-tree in sorted order?
body: <p>I want to sort a long list, so I put all the elements into a B-tree (each element takes O(log n) time to insert).</p>
  
  <p>Once sorted, I need to read back the elements.</p>
  
  <p>Do you know how it is done how long it is to read all the objects in a B-tree?</p>
  
  <p>Thanks!</p>