MySQL 5.7 OCP考试认证题库包含答案及解析

Question: 1

A MySQL database uses all InnoDB tables and is configured as follows:

#MySQL 数据库使用所有 InnoDB 表，配置如下：

shell>cat/ etc/ my.cnf

[mysqld]

log-bin

server-id=1

You will be setting up a replication slave by using mysqldump. You will need a consistent backup

taken from your running production server. The process should have minimal impact to active

B. --lock-all-tables

C. --create-apply-log

D. --single-transaction

E. --master-data

Answer: DE

Question: 2

Consider the key buffer in a MySQL server. Which two statements are true about this feature?

#考虑 MySQL 服务器中的 key buffer。关于这个特性，哪两种说法是正确的？

A. It caches index blocks for MyISAM tables only.

#它只缓存 MyISAM 表的索引块。

E. It caches index blocks for InnoDB tables only.

# E.它只缓存 InnoDB 表的索引块。

Answer: A,C

Question: 3

You have a MySQL replication setup and you intentionally stop the SQL thread on the slave.

#您有一个 MySQL 复制设置，并且有意停止从机上的 SQL 线程。

mysql> SHOW SLAVE STATUS\ G

Slave_IO_Running: Yes

Slave_SQL_Running: No

What are two reasons that you may stop the SQL thread on the slave while keeping the I/ O

#允许在减少负载的情况下创建备份

C. to allow for point-in-time recovery on the slave

#允许从机上的时间点恢复

D. to prevent schema changes from propagating to the slave before they are validated

# D.防止模式更改在验证之前传播到从属服务器

E. to prevent any transaction experiencing a deadlock

Answer:BC

Question: 4

Which three statements correctly describe MySQL InnoDB Cluster?

#哪三个语句正确地描述了 MySQL InnoDB 集群？

D. There is support for automatic failover when one node fails.

#当一个节点发生故障时，支持自动故障转移。

E. The data is automatically shared between the nodes.

# E.数据在节点之间自动共享。

F. Each query will be executed in parallel across the nodes.

# F.每个查询将跨节点并行执行。

Answer: ABD

Question: 5

How does the InnoDB storage engine handle deadlocks when they are detected?

#当检测到死锁时，InnoDB 存储引擎如何处理它们？

D. The transaction isolation level determines which transaction is rolled back.

# D.事务隔离级别决定回滚哪个事务。

E. The innodb_locks_unsafe_for_binlog setting determines which transaction is rolled back.

# E.innodb_locks_unsafe_for_binlog 设置确定回滚哪个事务。

Answer: C

Question: 6

Which three allocate memory per thread in MySQL?

#在 MySQL 中，哪三个线程分配内存？

A. query cache

B. thread cache

You are setting up a new installation of MySQL Server 5.7 (a GA release.) You have used a ZIP or

TAR package to ensure that the mysqld binary, along with its support files, such as plug-ins and

error messages, now exist on the host.

Assume that the default datadir exists on the host. You installed the binary in the default

location (the default --basedir value) for your operating system.

Which step should you perform before defining your own databases and database tables?

#您正在安装 MySQL Server 5.7（GA 释放）的新安装。您已经使用了 ZIP 或 TAR 包，以确保

MySQL 二进制文件及其支持文件（例如插件和错误消息）现在存在于主机上。

假设默认 DATADIR 存在于主机上。您将二进制文件安装在操作系统的默认位置（默认值

--basedir 值）。在定义自己的数据库和数据库表之前，应该执行哪一步？

D. Set an exception in the host machine’s firewall to allow external users to talk to mysqld.

# D.在主机防火墙中设置一个例外，允许外部用户与 mysqld 对话。

E. Create additional login accounts (so that everyone does not need to log in as root) and

assign them appropriate privileges.

# E.创建额外的登录帐户（这样每个人都不需要以根用户身份登录）并为他们分配适当的权

Answer: A

Question: 8

#哪两个选项描述 MySQL 服务器如何分配内存？

A. Each connection may have its own per-thread memory allocations.

# A.每个连接可能有自己的每线程内存分配。

B. Thread memory is pre-allocated up to thread_cache_size for performance.

Question: 9

Which two statements are true about InnoDB auto-increment locking?

#关于 InnoDB 自动增量锁定，哪两种说法是正确的？

A. InnoDB never uses table_level locks.

# A.InnoDB 从不使用表级锁。

B. InnoDB always protects auto-increment updates with a table-level lock

# B.InnoDB 总是使用表级锁保护自动增量更新

C. InnoDB does not use locks to enforce auto-increment uniqueness.

# C.InnoDB 不使用锁来强制自动增量唯一性。