DB/IQ QA+

DB/IQ QA+ is a DB/IQ suite module dedicated to optimizing and stabilizing Db2 for z/OS dynamic SQL statements. It leverages the Db2 dynamic statement cache (execution statistics, frequency, resource usage) to identify the best candidates and lock in their access paths, delivering more consistent and predictable performance over time.

Since Db2 for z/OS v12, it has been possible to stabilize the access paths of dynamic SQL queries that are cached and executed repeatedly, in order to achieve performance stability comparable to applications using static SQL.

Db2 plan stabilization (available starting with Db2 v12 and later releases) enables dynamic queries—compiled at runtime and subject to performance variability—to be converted into static queries with a fixed execution plan.

This capability is particularly valuable in environments where performance predictability is critical (banking, insurance, telecommunications). The primary benefit is clear: improved performance and, above all, more consistent performance.

To enhance the performance of your Db2 for z/OS environment, you can therefore stabilize selected queries from the dynamic statement cache.

One essential question remains: which ones? Typically, those executed most frequently—but identifying them requires analyzing and exploring the Db2 cache.

DB/IQ QA+ provides a simple and intuitive approach to stabilizing your dynamic queries through a user-friendly interface. The tool enables DBAs to browse the Db2 dynamic statement cache (including execution statistics) and easily select the statements to be stabilized.