题目内容（请给出正确答案）

[单选题]

LOG file must be used in the recovery of database. To re-execute the transaction that has been committed before failure time, which command should be used on the LOG records ？

A.Undo

B.Redo

C.COMMIT

D.ROLLBACK

提问人：网友zzsufo 发布时间：2022-01-07

参考答案

查看官方参考答案

如搜索结果不匹配，请联系老师获取答案

网友答案

查看全部（）

· 有4位网友选择 B，占比44.44%
· 有2位网友选择 A，占比22.22%
· 有2位网友选择 C，占比22.22%
· 有1位网友选择 D，占比11.11%

ABCD

提交我的答案

登录提交答案，可赢取奖励机会。

登录/注册

您可能会需要：

重置密码查看订单联系客服

安装简答题APP，拍照搜题省时又省心！

更多“LOG file must be used in the r…”相关的问题

第1题

If the interest rate this year is 8% and the interest rate next year will be 10%，what is the future value of $100 after 2 years？What is the present value of a payment of $100 to be received in 2 years？

点击查看答案

第2题

What are the functions of a cover letter?

A、A cover letter introduces you and your resume to the employer.

B、A cover letter is as important as a resume.

C、A cover letter demonstrates your writing skills.

D、A cover letter can be sent to all employers.

点击查看答案

第3题

If you enter a temple in Sri Lanka, you’d better __________.

A、cover your shoulders and legs.

B、showcase a Buddha tattoo.

C、touch the top of the head of Buddhist monks.

D、neither consume alcohol or smoke.

点击查看答案

第4题

“A transaction should be ended either by commit or abort”, indicates which property of transaction ?

A、Atomicity

B、Consistency

C、Isolation

D、Durability

点击查看答案

第5题

After failure, the system needs to recover before any transaction to run. Which answer is used in recovery ?

A、Table

B、Log

C、View

D、Graph

点击查看答案

第6题

Which of the following statement is WRONG ?

A、Concurrent schedule is efficient

B、2PL can NOT avoid dead lock

C、A schedule is RIGHT if and only if obey 2PL

D、Recovery needs log files

点击查看答案

第7题

In the ACID attributes, “Either all operations of the transaction are properly reflected in the database or none are” is called ____________.

点击查看答案

第8题

“Once a transaction committed, changes to database must be persistent”, indicates which property of transaction :

点击查看答案

第9题

A transaction can be in any of one of the five states, Active, Partially committed, Failed, ___________, and Aborted.

点击查看答案

第10题

Which of the following attributes in E-R diagram will NOT appeared in the relation schema mapped by the E-R diagram ?

A、Multi-valued attributes

B、Derived attributes

C、Single-valued attributes

D、Simple attribute

点击查看答案

警告：系统检测到您的账号存在安全风险

为了保护您的账号安全，请在“简答题”公众号进行验证，点击“官网服务”-“账号验证”后输入验证码“”完成验证，验证成功后方可继续查看答案！

微信搜一搜

简答题

点击打开微信

警告：系统检测到您的账号存在安全风险

抱歉，您的账号因涉嫌违反简答题购买须知被冻结。您可在“简答题”微信公众号中的“官网服务”-“账号解封申请”申请解封，或联系客服。

微信搜一搜

简答题

点击打开微信