title: Should the ID column be the first column of a table?
body: <p>I have a table with a natural 5 columns primary key but I want to change that primary key into a unique key and I want to add an autoincrement integer clustered Primary Key.</p>
  
  <p>Can I just add an ID column + clustered PK or should the ID column always be the first column of a table? I know that just adding will work but <strong>I am afraid of performance issues.</strong> </p>
  
  <p>If the ID column should be the first then I have to do a data migration.</p>