The Log Switch Time alarm occurs if the amount of time spent waiting for log switch events exceeds a threshold.
A log switch must occur whenever a log file is full. Usually the log switch time is trivial, but it can become significant in the following circumstances:
These problems usually occur when redo log I/O rates are sub-optimal, or when the number or size of redo logs is insufficient. For more information, see Improve Redo Log Writer Performance.