SQL Server 2008 系統登入使用者##MS_PolicyEventProcessingLogin##被誤刪後的恢復

客戶SQL Server 2008R2資料庫，在清理資料庫使用者時，連同系統登入使用者“##MS_PolicyEventProcessingLogin##”等也一併刪除了，後在系統日誌中發現大量如下提示，每5秒報一次錯誤。

描述:

針對佇列 'msdb.dbo.syspolicy_event_queue' 執行的啟用過程 '[dbo].[sp_syspolicy_events_reader]' 輸出以下資訊: 'Cannot execute as the database principal because the principal "##MS_PolicyEventProcessingLogin##" does not exist, this type of principal cannot be impersonated, or you do not have permission.'

在SQL Server的日誌中，也有對應的錯誤提示：

訊息

The activated proc '[dbo].[sp_syspolicy_events_reader]' running on queue 'msdb.dbo.syspolicy_event_queue' output the following:  'Cannot execute as the database principal because the principal "##MS_PolicyEventProcessingLogin##" does not exist, this type of principal cannot be impersonated, or you do not have permission.'