ORA-00275: media recovery has already been started
Cause: An attempt was made to start a second media recovery operation in the same session.
Action: Complete or cancel the first media recovery session or start another session to perform media recovery.
ORA-00275: media recovery has already been started
ORA-00275 occurs when attempting to perform media recovery on a database instance, and the database already has an active media recovery session.
ORA-00275发生时，当尝试对数据库实例执行媒体恢复，而数据库已经具有一个活动的媒体恢复会话。
1. 使用SQLPlus连接到数据库实例，执行SHOW ALL参数，查看DB_RECOVERY_FILE_DEST参数的值。
2.如果DB_RECOVERY_FILE_DEST参数被设置为预定义的值，则执行以下SQL语句：
ALTER SYSTEM SET DB_RECOVERY_FILE_DEST=’你的路径’ SCOPE=SPFILE;
3. 重新启动实例，并且重新运行媒体恢复操作。