MySQL 8.0 OCP 英文题库解析（十四）_examine this partial output for innodb cluster sta
Oracle 为庆祝 MySQL 30 周年，截止到 2025.07.31 之前。所有人均可以免费考取原价245美元的MySQL OCP 认证。
从今天开始，将英文题库免费公布出来，并进行解析，帮助大家在一个月之内轻松通过OCP认证。
本期公布试题121~130
试题121:
Examine this SQL statement:mysql> GRANT r_read@localhost To mark WITH ADMIN OPTION;Which two are true? (Choose two.) D)Mark can revoke the r_read@localhost role from another role. [正确] C)Mark can grant the r_read@localhost role to another user. [正确] A)Mark can grant the privileges assigned to the r_ read@ localhost role to another user. [错误] E)ADMIN OPTION allows Mark to drop the role. [错误] B)ADMIN OPTION causes the role to be activated by default. [错误] F)Mark must connect from localhost to activate the r_ read@localhost role. [错误]解析
SQL语句分析：GRANT r_read@localhost TO mark WITH ADMIN OPTION正确选项D) Mark可以撤销另一个角色的r_read@localhost角色C) Mark可以将r_read@localhost角色授予其他用户中文解析这个SQL语句授予用户\'mark\'对角色\'r_read@localhost\'的管理权限(WITH ADMIN OPTION)，这意味着： WITH ADMIN OPTION的作用： 允许mark用户将这个角色(r_read@localhost)授予其他用户(选项C正确) 允许mark用户撤销其他用户/角色的这个角色(选项D正确) 但不会自动将角色本身的权限授予mark用户 错误选项分析： A) 错误 - WITH ADMIN OPTION只允许管理角色分配，不是直接授予角色包含的权限 E) 错误 - ADMIN OPTION不提供删除角色的权限 B) 错误 - ADMIN OPTION与角色是否默认激活无关 F) 错误 - 角色激活与连接来源无直接关系，这是角色使用问题而非分配问题试题122:
C)Manual download of separate product packages is required before installing them through MySQL Installer. [正确] E)It performs product upgrades. [错误] A)It provides only GUI-driven, interactive installations. [错误] B)It installs most Oracle MySQL products. [正确] D)It provides a uniform installation wizard across multiple platforms. [错误] 解析
B) It installs most Oracle MySQL products. [正确] (它能安装大多数Oracle MySQL产品)C) Manual download of separate product packages is required before installing them through MySQL Installer.[正确] (通过MySQL Installer安装前需要手动下载单独的产品包)A) It provides only GUI-driven, interactive installations.(错误 - 它不仅提供GUI驱动的交互式安装，还支持静默安装模式)D) It provides a uniform installation wizard across multiple platforms.(错误 - 它不提供跨平台的统一安装向导，仅支持Windows平台)E) It performs product upgrades.(错误 - 它的主要功能是安装而非产品升级)试题123:
Choose threeWhich three actions are effective in capacity planning? B)buying more RAM [错误] C)buying more disk [错误] G)monitoring OS resources for patterns [正确] F)upgrading to the latest application version [错误] A)adding circular replication nodes for increased DML capability [错误] E)basing expected growth on an average of the last 3 years [正确] D)buying more CPU [错误] H)consulting the application team about any future projects and use [正确] 解析
容量规划的有效措施分析正确选项 (Choose three)G) monitoring OS resources for patterns(监控操作系统资源使用模式)E) basing expected growth on an average of the last 3 years(基于过去3年的平均值预测增长)H) consulting the application team about any future projects and use(咨询应用团队关于未来项目和使用情况)错误选项分析B) buying more RAM(错误 - 单纯购买更多内存是解决方案而非规划行为)C) buying more disk(错误 - 单纯购买更多磁盘是解决方案而非规划行为)F) upgrading to the latest application version(错误 - 升级应用版本是实施行为而非规划行为)A) adding circular replication nodes for increased DML capability(错误 - 添加复制节点是架构扩展而非规划行为)D) buying more CPU(错误 - 单纯购买更多CPU是解决方案而非规划行为)试题124:
Choose the best answer.Four nodes are configured to use circular replication. Examine these configuration parameters for each each node:slave_parallel_type=DATABASE ; slave_parallel_workers=4slave_preserve_commit_order=0 Which statement is true? B)Cross-database constraints can cause database inconsistency. [正确] E)Setting slave_preserve_commit_order to ON will improve data consistency. [错误] C)Setting slave_parallel_type=DATABASE won\'t work for circular replication; it should be set to LOGICAL_CLOCK. [错误] F)Setting transaction_allow_batching to ON will improve data consistency. [错误] D)Increasing slave_parallel_workers will improve high availability. [错误] A)Each slave thread is responsible for updating a specific database. [错误]解析
B) Cross-database constraints can cause database inconsistency.(跨数据库约束可能导致数据库不一致)错误选项解析A) Each slave thread is responsible for updating a specific database.(错误 - 每个slave线程不专门负责特定数据库，DATABASE并行类型是按数据库并行化)C) Setting slave_parallel_type=DATABASE won\'t work for circular replication; it should be set to LOGICAL_CLOCK.(错误 - DATABASE并行类型在循环复制中是可用的，只是有特定限制)D) Increasing slave_parallel_workers will improve high availability.(错误 - 增加并行工作线程数不直接影响高可用性)E) Setting slave_preserve_commit_order to ON will improve data consistency.(错误 - 在DATABASE并行类型下此设置不影响跨数据库事务顺序)F) Setting transaction_allow_batching to ON will improve data consistency.(错误 - 事务批处理会降低一致性保证)试题125:
Examine this partial output for InnoDB Cluster status:“topology”;“host1:3377”:”address”;”host1:3377”,“mode”:”R/W”,.......“STATUS”: ”ONLINE”,“version”;”8.0.18’,“host1:3377”:”address”;”host2:3377”,“mode”:”R/O”,.... ...“STATUS”:”MISSING”,,“host1:3377”:”address”;”host3:3377”,“mode”:”R/O”,.......“ST ATUS”:”ONLINE”,“version”;”8.0.18’Which statement explains the state of the instance deployed on host2? C)It can be recovered from a donor instance on host3 by cloning using the command cluster.rejoinInstance (\'@host3:3377\'). [正确] E)It can rejoin the cluster by using the command dba. rebootClusterFromCompleteOutage(). [错误] A)It can rejoin the cluster by using the command cluster.addInstance (\'@host3:3377\'). [错误] D)It has been removed from the cluster by using the command STOP GROUP_REPLICATION;. . [错误] B)It has been expelled from the cluster because of a transaction error. [错误] 解析
检查InnoDB Cluster的部分状态输出：\"topology\": { \"host1:3377\": { \"address\": \"host1:3377\", \"mode\": \"R/W\", \"STATUS\": \"ONLINE\", \"version\": \"8.0.18\" }, \"host2:3377\": { \"address\": \"host2:3377\", \"mode\": \"R/O\", \"STATUS\": \"MISSING\" }, \"host3:3377\": { \"address\": \"host3:3377\", \"mode\": \"R/O\", \"STATUS\": \"ONLINE\", \"version\": \"8.0.18\" }}哪个选项解释了部署在host2上的实例状态？C) It can be recovered from a donor instance on host3 by cloning using the command cluster.rejoinInstance (\'@host3:3377\').(它可以通过使用cluster.rejoinInstance命令从host3上的捐赠者实例克隆恢复)解析： host2状态为\"MISSING\"但未被驱逐(expelled) 可以通过从在线的host3实例克隆数据重新加入集群 cluster.rejoinInstance是正确命令错误选项E) It can rejoin the cluster by using the command dba.rebootClusterFromCompleteOutage().(它可以通过使用dba.rebootClusterFromCompleteOutage()命令重新加入集群)错误原因： 该命令用于整个集群完全中断后的恢复 不适用于单个节点恢复A) It can rejoin the cluster by using the command cluster.addInstance (\'@host3:3377\').(它可以通过使用cluster.addInstance命令重新加入集群)错误原因： addInstance用于添加全新实例 不适用于已配置但MISSING的实例恢复D) It has been removed from the cluster by using the command STOP GROUP_REPLICATION;.(它已通过使用STOP GROUP_REPLICATION命令从集群中移除)错误原因： 主动停止复制会显示为OFFLINE而非MISSING 题目未提供人为操作的证据B) It has been expelled from the cluster because of a transaction error.(它因事务错误被驱逐出集群)错误原因： 被驱逐的实例会显示为\"ERROR\"或明确标记为expelled \"MISSING\"仅表示无法连接试题126:
Choose the best answer.Examine this command:shell> mysqldump --no-create-info --all-databases --result-file=dump.sql Which statement is true? D)It will not write CREATE TABLE statements. [正确] A)It will not write CREATE TABLESPACE statements. [错误] B)It will not write CREATE LOGFILE GROUP statements. [错误] C)It will not write CREATE DATABASE statements. [错误] 解析
D) It will not write CREATE TABLE statements.(该命令不会写入CREATE TABLE语句) A) 错误 - TABLESPACE创建语句不受此参数影响 B) 错误 - LOGFILE GROUP创建语句不受此参数影响 C) 错误 - CREATE DATABASE语句不受此参数影响(除非使用--no-create-db)试题127:
MySQL programs look for option files in standard locations.Which method will show the option files and the order in which they are read? C)shell> mysqladmin --debug [错误] A)mysql> SHOW GLOBAL VARIABLES; [错误] B)shell> mysql --print-defaults [错误] D)shell> mysqld - -help --verbose [正确] 解析
正确选项D： mysqld --help --verbose命令会显示： MySQL服务器启动时读取的选项文件列表 这些文件的读取顺序 所有可用配置参数及其默认值 这是官方推荐的查看选项文件顺序的标准方法 MySQL程序按以下标准顺序读取选项文件： /etc/my.cnf /etc/mysql/my.cnf SYSCONFDIR/my.cnf $MYSQL_HOME/my.cnf ~/.my.cnf (用户特定) ~/.mylogin.cnf (加密的登录路径文件) --help --verbose是最全面查看MySQL配置信息的标准方式开启新对话试题128:
Choose the best answer.Examine this command, which executes successfully:$ mysqlbackup -user=dba --password --port=3306 --with-timestamp --only-known-file-types--backupdir=/export/backups backup Which statement is true? C)Only non-encrypted files are backed up. [错误] E)The backup includes only data files and their metadata. [错误] D)Only files for MySQL or its built-in storage engines are backed up. [正确] A)Only tables stored in their own tablespaces are backed up. [错误] B)Only InnoDB data and log files are backed up. [错误] 解析
关键参数： --only-known-file-types：仅备份MySQL识别的文件类型 --with-timestamp：在备份目录中添加时间戳 --backup-dir：指定备份目录正确选项D： --only-known-file-types参数确保只备份： MySQL系统文件 内置存储引擎(如InnoDB、MyISAM等)的文件 不包括未知或第三方存储引擎的文件错误选项分析： A) 错误 - 不限于单独表空间存储的表 B) 错误 - 不只InnoDB文件，还包括其他引擎文件 C) 错误 - 参数不影响加密文件的备份 E) 错误 - 还包括日志文件等其他MySQL文件试题129:
What does the slave I/O thread do? B)connects to the master and requests it to send updates recorded in its binary logs [正确] C)acquires a lock on the binary log for reading each event to be sent to the slave [错误] D)reads the relay log and executes the events contained in them [错误] A)monitors and schedules I/O calls to the subsystem for the relay logs [错误]解析
B) connects to the master and requests it to send updates recorded in its binary logs(连接到主库并请求发送记录在其二进制日志中的更新)Slave I/O 线程功能详解 主要职责： 建立与主库的连接 请求主库发送二进制日志(binlog)事件 将接收到的binlog事件写入从库的relay log(中继日志) 保持与主库的长连接，持续获取更新A) monitors and schedules I/O calls to the subsystem for the relay logs(监控和调度对中继日志子系统的I/O调用) 错误：这是操作系统层面的I/O调度，不是I/O线程的工作C) acquires a lock on the binary log for reading each event to be sent to the slave(获取二进制日志锁以读取要发送给从库的每个事件) 错误：这是主库binlog dump线程的行为，不是从库I/O线程的D) reads the relay log and executes the events contained in them(读取中继日志并执行其中的事件) 错误：这是从库SQL线程的职责试题130:
Choose the best answer.Which statement is true about the my.ini file on a Windows platform while MySQL server is running? C)Editing the file will immediately change the running server configuration. [错误] D)Using SET PERSIST will update the my.ini file. [错误] A)MySQL server does not use the my.ini option file for server configuration options. [错误] B)The option file is read by the MySQL server service only at start up. [正确] 解析
my.ini文件在Windows平台的特点 正确选项B分析： MySQL服务只在启动时读取my.ini配置文件 运行时修改不会自动生效 需要重启MySQL服务才能使配置变更生效A) MySQL server does not use the my.ini option file for server configuration options.(MySQL服务器不使用my.ini选项文件进行服务器配置) 错误：my.ini是Windows平台MySQL的主要配置文件C) Editing the file will immediately change the running server configuration.(编辑文件会立即改变运行中的服务器配置) 错误：必须重启服务才能使配置变更生效D) Using SET PERSIST will update the my.ini file.(使用SET PERSIST会更新my.ini文件) 错误：SET PERSIST会更新数据目录下的mysqld-auto.cnf文件，而非my.ini
