SAS Certification Prep Guide, 4th Edition

Deciding Whether to Create an Index

Overview

An index can reduce the time required to locate a set of rows, especially for a large data file. However, there are costs associated with creating, storing, and maintaining the index. When deciding whether to create an index, you must weigh any benefits in performance improvement against the costs of increased resource usage.

Note: This chapter discusses the benefits and costs that are associated with using indexes specifically with PROC SQL. To learn about the costs and benefits of using indexes with other SAS procedures, see the SAS documentation.

PROC SQL Queries That Can Be Optimized by an Index

To use indexes effectively with PROC SQL, it is important to know the classes of queries that ...