title: is it good to have primary keys as Identity field
body: <p>I have read a lot of articles about whether we should have primary keys that are identity columns, but I'm still confused.</p>
  
  <p>There are advantages of making columns are identity as it would give better performance in joins and provides data consistency. But there is a major drawback associated with identity ,i.e.When INSERT statement fails, still the IDENTITY value increases If a transaction is rolled back, the new IDENTITY column value isn't rolled back, so we end up with gaps in sequencing. I can use GUIDs (by using NEWSEQUENTIALID) but it reduces performance.</p>