title: Improve oracle query performance without indexing
body: <p>What are some things I can do to improve query performance of an oracle query without creating indexes?</p>
  
  <p>Here is the query I'm trying to run faster:</p>
  
  <pre><code>SELECT c.ClaimNumber, a.ItemDate, c.DTN, b.FilePath
  FROM items a,
  itempages b,
  keygroupdata c
  WHERE a.ItemType IN (112,115,189,241)
  AND a.ItemNum = b.ItemNum
  AND b.ItemNum = c.ItemNum
  ORDER BY a.DateStored DESC
  </code></pre>
  
  <p>None of these columns are indexed and each of the tables contains millions of records. Needless to say, it takes over 3 and half minutes for the query to execute. This is a third party database in a production environment and I'm not allowed to create any indexes so any performance improvements would have to be made to the query itself.</p>
  
  <p>Thanks!</p>