title: Advantages and disadvantages of having composite primary key
body: <p>Instead of having a composite primary key (this table maintains the relationship between the two tables which represents two entities [two tables]), the design is proposed to have <code>identity</code> column as primary key and the unique data constraint is enforced over two columns which represents the data from the primary key of entities.</p>
  
  <p>For me having identity column for each relationship table is breaking the normalisation rules.</p>
  
  <ul>
  <li>What is the industry standards?</li>
  <li>What are the considerations to make before making the design decision on this?</li>
  <li>Which approach is right?</li>
  </ul>