title: Compare TWO tables with same schema for data differences
body: <p>I am working on a typical problem where I need to compare TWO tables with exactly same schema for data differences.
  Assume database as MS SQL or ORACLE.</p>
  
  <p>To be more precise here is what I am trying to achieve:</p>
  
  <ol>
  <li>I have a table ORG with some data</li>
  <li>I am creating a copy of table ORG as BACKUP</li>
  <li>Now I want to update some SPECIFIC columns in some SPECIFIC rows of the table ORG.</li>
  </ol>
  
  <p>What is the EASIEST and EFFICIENT way to find the difference between tables BACKUP and ORG?</p>
  
  <p>I see few options like using UNIONS, PIVOT, UNPIVOT, etc.. But I am confused and need some guidance on best way to proceed.</p>
  
  <p>Thanks,</p>