title: Row number functionality in Hive
body: <p>How can I generate row numbers for an existing table while running a select query?<br/>
  For example:</p>
  
  <pre><code>select row_number(), * from emp;
  </code></pre>
  
  <p>I am using hive 0.13. I can't access external jars or udfs in my environment.
  The underlying files are in parquet format.</p>
  
  <p>Thanks in advance!</p>