The Version Store Generation Ratio alert provides the percentage by which the tempdb version store generation rate exceeds the cleanup rate. This alert is disabled by default and occurs only on instances running SQL Server 2005 or above.
You can raise this alert only when at least one minute elapses between alert refreshes as version store cleanup occurs once per minute.
This alert is raised based on the diagnostic data collection interval specified in Server Properties. For more information, see Set general server options.