Assume that you have a session whose deadlock priority is set to a value greater than -10 (by using the syntax of SET DEADLOCK_PRIORITY HIGH | NORMAL | LOW, or by using an integer value greater than -10). When the session executes the ALTER PARTITION FUNCTION statement, the deadlock priority of the session is temporarily set to -10 during the process, and the session is always chosen as the deadlock victim. The user-defined value isn't honored.
- Because the deadlock priority mnemonics of "HIGH / NORMAL / LOW" map to their corresponding integer values of "5 / 0 / -5", setting the deadlock priority of other sessions to LOW won't help. For more information about deadlock priorities and their numeric values, see SET DEADLOCK_PRIORITY (Transact-SQL).
- After you install this fix, to allow the ALTER PARTITION FUNCTION statement to honor the current user-defined session deadlock priority, use trace flag 1237.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.