The waits by type page shows you the most commonly occurring waits on your SQL Server.
- Row: Just the row number in the grid.
- Type: The name of this wait type.
- Wait Seconds: The total amount of time this type of wait has been waiting since SQL Server was last restarted, or since the wait stats were last cleared.
- Percent: The percentage that this wait takes up of all the waits on the system.
You can clear the wait stats with the following command
DBCC SQLPERF (‘sys.dm_os_wait_stats’, CLEAR);