IDUG EMEA 2026

In the world of Db2 for z/OS, SQL performance tuning is one of the most critical and often most complex of DBA tasks. While static SQL has long been the standing order for traditional mainframe applications, the growing use of dynamic SQL - driven by modern applications, APIs, and distributed workloads - has changed the tuning game.Dynamic SQL’s agility and flexibility introduces a new layer of complexity that can hinder performance if not well managed and cause inconsistent performance and even be unpredictable. Dynamic SQL is becoming more prevalent as agile development and hybrid workloads become the norm. But with the flexibility of dynamic SQL comes responsibility - DBAs must adapt and develop new ways of monitoring and tuning dynamic workloads in real-time and across the application lifecycle. Colin Oakhill will share a proven approach to bring order to chaos by giving DBAs the visibility, control, and insight they need to ensure that dynamic SQL performs efficiently and predic

Poorly written or optimized Db2 SQL queries can use huge amounts of CPU and render applications unusable causing business impact.
This session will cover the different types of access paths the Db2 Optimizes uses to return data for queries and discuss their merits and use cases. We will look at the data written by the DB2 optimizer in the EXPLAIN tables and how we can interpret the data using AI to determine if an SQL is going to be cheap or expensive to run.
The session will cover filter factors and the role of RUNSTATS on access path selection and cover how one can influence the access path.

SQL injection remains one of the most damaging classes of flaws against data-driven applications—and the workflow around it has changed: security testers and attackers alike can pair classic tooling with generative AI to iterate payloads faster, interpret ambiguous responses, and explore injection chains with less manual trial and error. This session focuses on Db2-backed applications: how SQL injection manifests in practice, how to recognize fragile dynamic SQL and unsafe integration patterns, and how to prioritize prevention (parameterization, safe composition, and tight error handling). We will connect that baseline to today’s landscape—examples include AI-assisted DAST/exploration tools, AI-augmented automation around sqlmap, and red-team harnesses that probe whether LLM-driven apps avoid unsafe database access—so you leave with a clearer understanding of both defenses and new risks.This is an upgraded version of my session on IDUG EMEA 2022: SQL Injection and Db2 - Pathology and P

It often makes sense for analytical applications to store the data in column organized tables instead of row organized tables to get better performance. Especially scans on column organized tables are different from scans on row organized tables. This presentation investigates these differences. One major difference is the usage of Synopsis tables to speed up scans. Therefore, we will look in depth at how Synopsis tables work, how one can check Synopsis tables e.g., with SQL statements, and how one can ensure to get "good" Synopis tables, i.e., Synopsis tables which allow the elimination of unneccesary page accesses during the scans of important queries.

Index pages splitting is a normal DB2 process when inserting or updating rows into table. However, this process can consume CPU resources and generate latch contention especially in a Data Sharing environment. Index page splits in also the main cause of index disorganization. In this presentation we will see how to identify costly index page splits and reduce their frequency with the help of RTS history tables.