文档解释
ORA-55511: Flashback Transaction experienced error in executing undo SQL
Cause: There was a constraint violation exception when executing in NOCASCADE_FORCE mode. Users could also get this error if appropriate supplemental logging is not enabled causing constraint dependencies to go unnoticed.
Action: Either use CASCADE or NONCONFLICT_ONLY options or add appropriate level for supplemental logging.
ORA-55511 错误表明,在试图使用 Flashback 事务执行 Undo 操作时出现了错误。
官方解释
ORA-55511: Flashback Transaction experienced error in executing undo SQL
Cause: An unexpected error occurred while flashback transaction was trying to execute undo SQL.
Action: Check for additional Oracle messages for the cause of the error and take the appropriate corrective action. The corrective action can involve either retrying the undo SQL or setting the flashback transaction back to its original position.
常见案例
ORA-55511 错误通常会出现在用户尝试使用 Flashback 事务回滚语句恢复之前删除的数据时,但是在执行这些回滚操作时出现了意外错误。
一般处理方法及步骤
1. 检查哪些原因可能会引起 ORA-55511 错误,例如:数据库不一致性,网络中断,文件头丢失等。
2. 为确保 Flashback 事务能够正常运行,使用系统的操作,如检查在问题出现前是否有相应的统计信息,分析等。
3. 如果解决方案无法达到预期的结果,请尝试再次回滚事务,并使用 undo_retention 并重新配置旧时间。
4. 如果 Flashback 事务仍然无法工作,那么你可以尝试使用 Export 导出以前的数据,并使用一个备份进行恢复。