title: How much space on disk does a nvarchar column occupy if the string inside are shorter than the maximum length
body: <p>I would like to know how much space will take in the hard disk a <code>nvarchar(N)</code> column for each record. Will it take 2 x N bytes (each character takes two bytes) or will it take different number of bytes depending on the data inside each record?</p>
  
  <p>For example, I can have a table with just one column of type <code>nvarchar(100)</code> which contains numbers like these:</p>
  
  <pre><code> 0000000000
   0000000001
   .....
   9999999999
  </code></pre>
  
  <p>I have 10 billions (10^10) records with ten characters each of them. How much space would it take in the hard disk? 20Gb? 200Gb?</p>