Chapter 6. Advanced SQL Coding
This chapter covers some the more advanced DB2 SQL features. The discussion begins with the constructs of subqueries, unions, and joins. Then we examine nested and common table expressions, the CASE expression with its if-then-else logic, row expressions, and OLAP features. Efficient query coding also requires a knowledge of how DB2 processes predicates. We look at how predicates are classified and data is filtered during query processing.