[bbk4754] 第27集 第三章 Flashback Table 04

Quiz

1、Flashback Query compares current data with data from the past.To do so,it uses both undo and redo data.

True

False

2、Select the correct statement

Flashback Version Query uses undo data and modifies data.

Flashback Version Query uses undo data and does not modify data.

Flashback Version Query uses both undo and redo data.

Flashback Table:Overview

• Flashback Table recovers tables to a specific point in time.
• Flashback Table is an in-plac operation.
• The database statys online.

Flashback Table

• Using Flashback Table,you can recover a table or tables to a specific point in time without restoreing a backup.

Flashback Table时，Oracle database会自动维护表的约束、索引、触发器等相关对象.

• Data is retrieved from the undo tablespace to perform a Flashback Table operation.
• You require the FLASHBACK ANY TABLE or the FLASHBACK object privilege on the specific table.
• SELECT,INSERT,DELETE,and ALTER privileges on the table to be flashed back are required.
• You must enable row movement on the table that you are performing the flashback operation on.

如何实现行移动的权限?

两种方式：

一、通过OEM，界面操作方式授权

二、通过command line方式实现授权

具体如下图所示:

Performing Flashback Table