title: Does a multi-column index work for single column selects too?
body: <p>I've got (for example) an index:</p>
  
  <pre><code>CREATE INDEX someIndex ON orders (customer, date);
  </code></pre>
  
  <p>Does this index only accelerate queries where <em>customer and date</em> are used or does it accelerate queries for a single-column like this too?</p>
  
  <pre><code>SELECT * FROM orders WHERE customer &gt; 33;
  </code></pre>
  
  <p>I'm using SQLite.</p>
  
  <hr>
  
  <p>If the answer is yes, why is it possible to create more than one index per table?</p>
  
  <hr>
  
  <p>Yet another question: How much faster is a combined index compared with two separat indexes when you use both columns in a query?</p>