HOT OFF THE PRESS and available for download now: Db2 12 for z/OS Optimizer
DB2 12 for z/OS has targeted performance to increase the success of new application deployments and integration of analytics.
This paper describes the enhancements delivered specifically by the query processing engine of DB2. This engine is generally called the optimizer or the Relational Data Services (RDS) components, which encompasses the query transformation, access path selection, run time, and parallelism.
DB2 12 for z/OS also delivers improvements targeted at OLTP applications, which are the realm of the Data Manager, Index Manager, and Buffer Manager components (to name a few), and are not identified here.
Although the performance measurement focus is based on reducing CPU, improvement in elapsed time is likely to be similarly achieved as CPU is reduced and performance constraints alleviated. However, elapsed time improvements can be achieved with parallelism, and DB2 12 does increase the percentage offload for parallel child tasks, which can further reduce chargeable CPU for analytics workloads.
The IBM® Redpaper™ contains the following sections:
- Why read further
- The performance focus in DB2 12 for z/OS
- UNION ALL and outer join performance
- Runtime optimizations
- Predicate optimizations
- User-Defined table function predicate optimizations
- Optimizer cost model enhancements
- RUNSTATS and optimizer-generated statistics profiles
- Static and dynamic plan stability
- Summary