Oracle Database 11g: Administration I — Question 22

Which three are true about UNDO data? (Choose three.)

Answer options

• A. It is used during online backups to guarantee their consistency
• B. It is used to roll back failed transactions
• C. It is used to recover dropped tables by using FLASHBACK TABLE … TO BEFORE DROP
• D. It is used to rewind a database by using FLASHBACK DATABASE
• E. It is used to provide read consistency
• F. It is used to enable ROLLBACK statements to roll back uncommitted updates

Correct answer: D, E, F

Explanation

The correct answers, D, E, and F, accurately describe the functions of UNDO data. D refers to using UNDO for FLASHBACK DATABASE, E highlights its role in maintaining read consistency, and F explains how it supports ROLLBACK operations. Options A, B, and C do not correctly define the primary uses of UNDO data.