Q171.Examine this MySQL client command to connect to a remote database:
mysql-h remote-example.org-u root–protocol=TCP–ssl-mode=
Which two–ss1-mode values will ensure that an X.509-compliant certificate will be used to establish the
SSL/TLS connection to MySQL?
A)VERIFY_CA
B)REQUIRED
C)DISABLED
D)PREFERRED
E)VERIEY_ IDENTITY
Answer:AE

選項A：VERIFY_CA：要求必須使用 SSL，并驗證證書頒發機構（CA）。這確保了使用的證書符合 X.509 標準，因為它會檢查證書是否由受信任的 CA 簽名。
選項B：REQUIRED：要求必須使用 SSL，但不一定會驗證服務器的證書是否符合 X.509 標準。
選項C：DISABLED：禁用 SSL，顯然不能滿足要求。
選項D：PREFERRED：表示優先使用 SSL，但不會強制使用，也不確保證書符合 X.509。
選項E：VERIFY_IDENTITY：要求必須使用 SSL，并驗證服務器的證書身份。這不僅驗證了證書是否由受信任的 CA 簽名，還確保服務器的證書身份與連接的主機名匹配，符合 X.509 標準

Q172.Many connects to a Linux MySQL Server from a client on a Windows machine.Examine this statement and
output:
mysql> SELECT USER () , CURRENT USER () ;
±-------------------------±--------------------+
|USER () | CURRENT_USER ( ) |
±-------------------------±--------------------+
|mary@192 .0.2.101 | mary@ % |
±-------------------------±--------------------+
row in set (0.00 sec)
Which two are true?
A)Mary connected using a UNIX socket.
B)Mary connected from a client machine whose IP address is 192.0.2.101.
C)Mary connected to the database server whose IP address is 192.0.2.101.
D)Mary has the privileges of account mary@%.
E)Mary authenticated to the account marye192.0.2.101.
Answer:BD

user():登錄的用戶
current_user()：驗證的權限用戶

Q173.Examine this command, which executes successfully:
mysqlbackup–defaults-file=/backups/server-my.cnf --backup-dir=/backups/full -copy-back
Which statement is true about the copy-back process?
A)It restores files from the backup directory to their original MySQL server locations .
B)The copy-back process makes inconsistent backups.
C)The copy-back process is used to overwrite a new backup over an existing backup.
D)It restores files from the data directory to their original MySQL server locations.
Answer:D

--backup_dir:mysql的備份文件路徑
-copy-back:從MySQL的備份文件恢復到數據庫原始的數據目錄，也就是--default-file所指向的配置文件中的datadir
官方文檔原文:Restores files from a directory backup to their original locations within the MySQL server.
官方原文可參考：https://dev.mysql.com/doc/mysql-enterprise-backup/8.0/en/backup-commands-restore.html
選項A：正確
選項B：copy-back 過程本身不會導致備份不一致，備份的一致性取決于備份時的設置和 MySQL 的狀態。
選項C：可查看官方文檔，copy-back不會覆蓋已存在的備份
選項D：錯誤
個人理解該答案應該選A

Q174.You are planning to take a full MySQL instance backup .
Which two factors will help to determine the backup strategy?
A)the expected size of the backup
B)how much down time is planned
C)the OS super user rights
D)the number of user accounts for the MySQL instance
E)the location of the physical server
Answer:AB

全備策略的指定：備份的所需要的磁盤空間，然后就是恢復時所需要停機的時間，所以AB是正確的，CDE對于備份策略的指定沒什么影響

Q175.Which three are characteristics of logical backups?
A)They consist of exact copies of database directories and files.
B)They can be created by mysqlbackup for InnoDB tables or by file-system commands, such as cp,
scp, tar, or rsync, for MyISAM tables .
C)They can be performed while the MySQL server is not running.
D)They can be run only against a running MySQL server.
E)They are machine independent and highly portable.
F)Backup and restore granularity is available at the server level, database level, or table level for any storage engine.
G)In addition to databases, backups can include any related files, such as log or configuration files.
Answer:DEF

選項A：邏輯備份不會拷貝數據路徑的文件
選項B：邏輯備份對于innodb可以用mysqlback進行備份，對于MyISAM使用的是cp，scp,tar或者rsync的方式
選項C：邏輯備份必須在數據庫運行期間執行
選項D：它們只能在正在運行的 MySQL 服務器上執行。所以正確
選項E：他們與機器無關，并且有很高的移植性，正確
選項F：對于任何存儲引擎備份和恢復的粒度可以是服務級別，數據庫或者表級別
選項G：邏輯備份不會拷貝redo,或者配置文件等

Q176.What does the slave SQL thread do?
A)reads the relay log and executes the events contained in them
B)connects to the master and asks it to send updates recorded in its binary logs
C)acquires a lock on the binary log for reading each event to be sent to the slave
D)monitors and maintains channel connections if multiple replication channels are used
Answer:A

選項A：讀取relay log并執行里面的事務，正確
選項B：sql線程并不會連接到master并且求其更新的記錄
選項C：在讀取每個要發送給從屬服務器的事件時，對二進制日志獲取鎖，這個是錯誤的，SQL線程讀取的是relay log，而不是binlog，所以不會對binlog加鎖
選項D：他不會監控和維護通道的連接

Q177.Examine this statement and output:

Which two SQL statements can jsmith execute?
A.UPDATE world.country SET Name=‘first’ ORDER BY Name LIMIT 1;
B.UPDATE world. country SET Name=‘new’ WHERE Name=‘old’;
C.UPDATE world.country SET Name=‘one’ LIMIT 1;
D.UPDATE world. country SET Name=CONCAT ('New ',Name);
E.UPDATE world.country SET Name='all’;
Answer:CE

其中ORDER BY,WHERE和CONCAT(('New ',Name)都需要select權限，所以無法執行。jsmith能執行的僅僅是update xxx set name=xxx。所以CE正確

Q178.Which three components comprise MySQL InnoDB Cluster to achieve database high availability?
A.MySQL Servers with Group Replication to replicate data to all members of the cluster
B.MySQL X Plugin to enable MySQL to use the X Protocol to speed up and monitor data replication
C.MySQL Semi-Sync replication plugin is used to provide cluster consistency
D.MySQL Shell to create and administer InnoDB Clusters using the built-in AdminAPI
E.MySQL Enterprise Backup to keep data consistent and always ready to be used.
F.MySQL Router to ensure that client requests are load balanced and routed to the correct servers
Answer:ABF

實現MySQL InnoDB Cluster的三個組件是MySQL router ，MySQL shell，MySQL MGR
所以答案應該是ADF

Q179.Examine these statements, which execute successfully:

What is the reason for the error?
A.John needs to reconnect to the database.
B.The statement was blocked by MySQL Firewall.
C.John has not activated the role.
D.The DBA needs to execute FLUSH PRIVILEGES.
Answer:D

從執行過程來看，john已經具有了r_world_rd@'%'角色的權限，而該角色可以對world庫進行select，此處報錯就是因為沒有進行flush privileges進行生效

Q180.Which three are features of MySQL Enterprise Backup?
A.the ability to use the output file, which contains sQL statements, as input to a MySQL session
B.the ability to edit the output file produced by MySQL Enterprise Backup
C.the ability to back up individual tables or individual tablespaces while your server instance is online
E.the ability to extract and restore individual rows from a backup
F.the ability to perform incremental backups
Answer:ACF

選項C：MySQL Enterprise Backup 支持在線備份個別表或表空間，這是其核心功能之一。
選項F：支持增量備份，即只備份自上次備份以來更改的數據，有助于減少備份時間和存儲需求。
A和B選項不太理解，暫時沒了解過，有懂得大佬麻煩幫忙解答下