Reports of contention for the log semaphore that protects the current page of the transaction log in cache. This data is meaningful for SMP environments only.
This category provides the following information:
Granted – number of times a task was granted the log semaphore immediately after it was requested. “% of total” reports the percentage of immediately granted requests as a percentage of the total number of log semaphore requests.
Local Waited – number of times a task that tried to flush its ULC had to wait for the log semaphore because it was already acquired by another task. “% of total” reports the percentage of tasks that had to wait for a log semaphore as a percentage of the total number of log semaphore requests.
Global Waited – number of times in a a shared disk cluster that a task that tried to flush its ULC had to wait for the log semaphore because another task had already acquired it on this or another node.
Total Log Semaphore Requests – total number of times tasks requested a log semaphore, including those granted immediately and those for which the task had to wait.