DB2 System Maintenance

We’ve checked into the Sort Work, EDM, RID and Buffer Pools. During this post, I’ll talk about some of the other standard places to check for performance improvements.

DB2 System Maintenance

The DB2 system software maintenance from IBM contains many fixes and performance adjustments in its software maintenance stream.When investigating this company’s maintenance levels, I discovered that their DB2 Version 8 system is behind on its maintenance level, which does not allow the latest performance improvements to be leveraged.Maintenance also needs to be coordinated with the implementation of pre-tested Service Packs from IBM.

These Service Packs test the compatibility between z/OS, MQ Series, CICS and DB2 and can help eliminate maintenance compatibility issues. By evaluating the latest release compatible with operating system, MQ Series, CICS and other software connecting to DB2, the company can apply the correct maintenance level for DB2 Version 8.Yearly maintenance plans need to be developed to help all departments understand the dependencies and the need to apply maintenance on a regular schedule.

Dynamic Statement Cache Pool Sizing and Settings

Additional analysis showed that the Dynamic Statement Cache (DSC) was being leveraged for application efficiency.This recently implemented feature was working well and only needed to be fine tuned.(The DSC holds SQL statements executed frequently and does not have to re-determine the access path, verify object existence or re-check security if various settings are the same in subsequent executions.)

A good portion of the SQL statements at the company were being cached letting, DB2 use the previously optimized SQL executing in the system.Leveraging the DSC area has usually shows a 2 to 3% CPU savings per SQL transaction and should be monitored closely to make sure to maintain its efficiency.

If your environment executes a large percent of dynamic SQL applications, the savings from leveraging the DSC area deserves on-going attention.

In Summary

Checking the various aspects of your DB2 system can have a great impact on the performance of your system. Take a look at these areas to improve system performance:

  • Is your DB2 System Maintenance at the appropriate level? Do you have maintenance plans that include checking the Service Pack levels?
  • Is your Dynamic Statement Cache Pool set to the appropriate size for your system? Are your settings encouraging SQL caching?


Dave Beulke is an internationally recognized DB2 consultant, DB2 trainer and education instructor.  Dave helps his clients improve their strategic direction, dramatically improve DB2 performance and reduce their CPU demand saving millions in their systems, databases and application areas within their mainframe, UNIX and Windows environments.

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