10.1. Introduction

A book on PROC SQL would not be complete without some discussion of query optimization and performance. Enabling a query to run efficiently involves writing code that can take advantage of the PROC SQL query optimizer. Because PROC SQL is designed to handle a variety of processes while accommodating small to large database environments, this chapter presents a number of query tuning strategies, techniques, and options to assist you to write more efficient PROC SQL code. In this chapter you will find tips and suggestions to help identify areas where a query’s inefficiencies may exist and to conduct the tuning process to achieve the best performance possible.