title: Adding database index for my Rails app
body: <p>I'm using MySQL and need to add some indexing to my tables for better performance.</p>
  
  <p>One of my common queries is something like this:</p>
  
  <pre><code>arrs = @book.items.where("type = 'A' and status not in ('cancelled','notransportation')").order("item_date, item_time asc")
  </code></pre>
  
  <p>How would you suggest adding an index that would help with such a query?</p>