title: Querying DUAL table and UNION ALL
body: <p>I have a query like below,</p>
  
  <pre><code> SELECT 1 AS SI, 'JAN' AS MoN FROM DUAL
   UNION ALL
   SELECT 2, 'FEB' FROM DUAL
   UNION ALL
   SELECT 3, 'MAR' FROM DUAL
   UNION ALL
   SELECT 4, 'APR' FROM DUAL
   UNION ALL
   SELECT 5, 'MAY' FROM DUAL
   UNION ALL
   SELECT 6, 'JUN' FROM DUAL
   UNION ALL
   SELECT 7, 'JUL' FROM DUAL
   UNION ALL
   SELECT 8, 'AUG' FROM DUAL
   UNION ALL
   SELECT 9, 'SEP' FROM DUAL
   UNION ALL
   SELECT 10, 'OCT' FROM DUAL
   UNION ALL
   SELECT 11, 'NOV' FROM DUAL
   UNION ALL
   SELECT 12, 'DEC' FROM DUAL ;
  </code></pre>
  
  <p>Would you please assist any best alternative or any performance improvement here ?</p>