OCP考题解析_043: flashback transaction query

Flashback Transaction Query详解

最新推荐文章于 2025-11-30 19:25:58 发布

最新推荐文章于 2025-11-30 19:25:58 发布 · 135 阅读

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#数据库

本文介绍了如何使用Flashback Transaction Query来获取指定事务的历史信息及Undo SQL。通过这些信息，可以了解特定事务的操作详情并实现事务恢复。文章还提供了一道OCP考试样题及其解析，帮助读者更好地理解该特性。

flashback transaction query可以从FLASHBACK_TRANSACTION_QUERY中获得指定事务的历史信息以及Undo_SQL

通过这个UNDO_SQL，查询具体事务所做的操作、我们就可以恢复特定的事务、flashback transaction query测试

OCP考题：

13. You executed the following query: 
    SELECT operation, undo_sql, table_name FROM flashback_transaction_query; 
    Which statement is correct regarding the query output? 

A. It would return information regarding only the last committed transaction. 

B. It would return only the active transactions in all the undosegments in the database.
 
C. It would return only the committed transactions in all the undo segments in the database. 

D. It would return both active and committed transactions in all the undo segments in the database. 

E. It would return information regarding the transactions that began and were committed in the last 30 minutes. 


Answer: D