ORA-00494: enqueue [CF] held for too long (more than 900 seconds) by 'inst 1, osid 5166'

凌晨收到同事電話，反饋應用程序訪問Oracle數據庫時報錯，當時現場現象確認： 1. 應用程序訪問不了數據庫，使用SQL Developer測試發現訪問不了數據庫。報ORA-12570 TNS ...