title: sql server multi column index queries
body: <p>If I have created a single index on two columns [lastName] and [firstName] in that order. If I then do a query to find the number of the people with first name daniel:</p>
  
  <pre><code>SELECT count(*)
  FROM people
  WHERE firstName = N'daniel'
  </code></pre>
  
  <p>will this search in each section of the first index (lastname) and use the secondary index (firstName) to quickly search through each of the blocks of LastName entries?</p>
  
  <p>This seems like an obvious thing to do and I assume that it is what happens but you know what they say about assumptions.</p>