Complete SAS Programming Guide - Learn SAS and Become a Data Ninja - Selecting Variable(s) for Your Index

The video tutorial discusses the importance of being selective when creating indexes in SAS, as they consume resources and take up disk space. It emphasizes the need to choose variables that are often used for subsetting data and are discriminant, meaning they select a small, specific set of observations. The tutorial advises against using non-discriminant variables like age or sex for indexing. It also demonstrates how to use the frequency procedure to determine if a variable is a good candidate for indexing, focusing on those with frequencies in the 1-15% range.

Why is it not advisable to use variables like age or ethnicity for indexing?

What frequency range is considered ideal for selecting variables to index?