Complete SAS Programming Guide - Learn SAS and Become a Data Ninja - Should You Use an Index?

The video tutorial discusses two main considerations for using an index: the size of the subset and the frequency of use. For large datasets, creating an index is beneficial if the subset needed is up to 15-20% of the total data. Beyond this, performance may degrade. Additionally, frequent use of an index makes it more cost-effective in terms of computing resources.

What happens to performance if the subset size exceeds 20%?

Why is the frequency of use an important consideration for creating an index?