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Troubleshooting access-path-related performance problems

Question & Answer


Question

How can I troubleshoot access-path-related performance problems?

Cause

A high percentage of access path performance issues and access path performance regressions can be resolved simply by making sure that you have a complete, current, and accurate set of statistics from the RUNSTATS utility. Even when the access path regression was triggered by a change in the DB2 maintenance level, in many cases, the underlying root cause is still inadequate statistics. The result is an unstable access path that is vulnerable to change.

Answer

To troubleshoot access path related performance problems, complete the following steps:
  1. Investigate the access path problem by using tools such as the statistics advisor, which is available with products such as IBM Data Server Manager, Db2 Query Workload Tuner for z/OS, and IBM Data Studio. Always use the statistics advisor before contacting IBM Software Support. For more information, see Investigating access path problems.
  2. If you are unable to resolve the problem, collect service SQL documentation for the problem, as described in Collecting data for access path performance problems and Collecting Service SQL documentation.

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Document Information

Modified date:
01 July 2019

UID

swg21206998