Resolving Transient Performance Problems

Transient performance problems are short-lived and do not appear in the Automatic Database Diagnostic Monitor (ADDM) analysis. ADDM tries to report the most significant performance problems during an analysis period in terms of their effect on DB time. If a problem lasts for a brief time, then its severity might be averaged out or minimized by other performance problems in the entire analysis period. Therefore, the problem may not appear in the ADDM findings. Whether or not a performance problem is captured by ADDM depends on its duration compared to the interval between the Automatic Workload Repository (AWR) snapshots.

If a performance problem lasts for a significant portion of the time between snapshots, then it will be captured by ADDM. For example, if the snapshot interval is one hour, then a performance problem that lasts 30 minutes should not be considered a transient performance problem because its duration represents a significant portion of the snapshot interval and will likely be captured by ADDM.

On the other hand, a performance problem that lasts 2 minutes could be transient because its duration is a small portion of the snapshot interval and will probably not appear in the ADDM findings. For example, if the system was slow between 10:00 p.m. and 10:10 p.m., and if the ADDM analysis for the time period between 10:00 p.m. and 11:00 p.m. does not show a problem, then a transient problem may have occurred for only a few minutes of the 10-minute interval.

Resolving Transient Performance Problems

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