How often have you created a new table (where you defined the Clustered Index and Primary Key using an Integer column with Identity properties as usual) and never wondered about the performance effects of that process? Seems like that is all I have done for the past several years. But, recently in my index performance research, I am starting to realize a well-defined Clustered Index may improve the overall database performance. We will look at 8 typical report queries varying clustered and non-clustered indexes using the AdventureWorks2017 database benchmarking (cpu time, logical IOs, and query plan cost) for each scenario. Results are very interesting, and they may surprise you. In some instances, a well-defined clustered index may outperform a covering non-clustered index for a set of queries. This presentation should raise your clustered index intellect to the outer limits of index technology.