Chapter 19: Adaptive Server Optimizer

This chapter introduces the Adaptive Server query optimizer and explains the steps performed when you run queries.

This chapter explains how costs for individual query clauses are determined.

Chapter 22, “Access Methods and Query Costing for Single Tables,”explains how these costs are used to estimate the logical, physical, and total I/O cost for single table queries.

Chapter 23, “Accessing Methods and Costing for Joins and Subqueries,” explains how costs are used when queries join two or more tables, or when queries include subqueries.