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Your instance has spent much of its In Oracle time waiting for the Redo Log.
| Description | |
| What to do next | Perform one of the following options: n Examine the related Oracle events (lower area), Redo Activity (upper area), to determine the problem type in the Statistics workspace. n Examine high Redo Log Buffer Wait statements in the Activity workspace. |
| Advice | Use any one of the typical problem scenarios described below. n If the log buffer size is too small, this usually results in long waits for the Log Buffer Space event. Consider increasing the Log_buffer parameter. n If the log buffer size is too big, this usually results in a low number of user commits, high redo wastage statistics, and long waits for the Log File Sync event. Consider decreasing the Log_buffer parameter and/or the hidden LOG_I/O_SIZE parameter. n If there are too many commits, this usually results in long waits for the Log File Sync event and the number of user commits is very high. Consider changing the application flow and logic (by decreasing the commit frequency or using bulk commits [resulting in larger transactions]). n If the LGWR is too slow, check whether Log File Sync is still the dominant event. This may be due to high values for Log File Parallel Write, or because there are not many commits. This may mean that the LGWR is underperforming. Consider moving the log file to a faster, dedicated device. Whenever the Log Buffer Space and Log File Sync events occur together, consider changing the hidden LOG_I/O_SIZE parameter. |
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