title: Teradata - Primary Index Fields and Performance
body: <p>I have a very large volatile table. I set the primary index to customer_id, which is the most unique column on the table. However, I can make the primary index more unique by combining it with customer_id, effective_dt, and group_id. </p>
  
  <p>I can make the primary index even more unique by adding more fields, but I was wondering if there is a point of diminishing return for adding more columns? </p>
  
  <p>Also, I noticed that as the more columns I add a unique primary index, the longer it takes to create the volatile table. Just my observation, but I am not sure if this is true?</p>
  
  <p>Thanks in advance.</p>