cursor: mutex S等待事件

cursor: mutex * events等待事件 cursor: mutex * events等待事件用於Cursor Parent 和 Cursor stats類型的操做： ‘Cursor: Mutex S’ ， 某個進程以SHRD S mode申請一個Mutex， 而該Mutex要麼被其餘進程已EXCL X mode所持有，要麼其餘進程正在更新mutex 上的Ref Count。

• 相關類型的操做通常是檢測父遊標或者CURSOR統計信息數據， 此外查詢V$SQLSTATS也會形成CURSOR statistics被查詢

詳見 《深刻理解Oracle中的Mutex》一文     A session waits on this event when it is requesting a mutex in shared mode, when another session is currently holding a this mutex in exclusive mode on the same cursor object. Solutions Solutions for mutex wait problems are very similar to each other. See Analysis of Waits on Mutexes for more information and troubleshooting ideas.