Oracle 1z0-908 Exam Dumps & Practice Test Questions
Question 1
You've discovered that the MySQL data directory and its contents have full read, write, and execute permissions for all users. What are the two main security risks associated with this situation? (Select two.)
A Unauthorized users might modify configuration files.
B Critical data files could be removed.
C Attackers could use SQL injection to corrupt the database.
D The MySQL executable files might be tampered with or erased.
E MySQL may take longer to start due to permission checks.
Answer: A, B
Explanation:
When the MySQL data directory has overly permissive access settings, it introduces multiple security vulnerabilities that can potentially compromise the integrity, availability, and confidentiality of the database.
A (Unauthorized users might modify configuration files) is correct. If the data directory and its configuration files have full permissions for all users, unauthorized individuals can modify MySQL configuration files (e.g., my.cnf), leading to misconfiguration or security breaches. They could change settings to weaken security, allow unauthorized connections, or even expose sensitive information.
B (Critical data files could be removed) is correct. One of the most dangerous risks of insecure file permissions is that critical data files, such as the actual database tables, could be removed, corrupted, or replaced by unauthorized users. This could result in the loss of valuable data and impact the integrity of the database system.
C (Attackers could use SQL injection to corrupt the database) is incorrect. SQL injection attacks typically exploit vulnerabilities in web applications and are not directly related to the permissions on the data directory. The data directory's permission settings would not directly facilitate or mitigate SQL injection risks.
D (The MySQL executable files might be tampered with or erased) is correct. If the MySQL executable files are also stored within the data directory (or a similar location with insecure permissions), attackers could tamper with or erase the MySQL binaries. This would lead to service disruptions and the potential for malicious code execution within the MySQL server.
E (MySQL may take longer to start due to permission checks) is incorrect. While excessive permissions might impact performance to some extent, the main security concern with having inappropriate file permissions is related to the possibility of unauthorized access and modification, not necessarily slower startup times.
In conclusion, the main security risks associated with overly permissive permissions on the MySQL data directory are the potential for unauthorized modifications to configuration files and the deletion or corruption of critical data files. Therefore, the correct answers are A and B.
Question 2
If the user account baduser@hostname has been compromised, which two MySQL commands will immediately block new connections from that user? (Select two.)
A ALTER USER baduser@hostname PASSWORD DISABLED;
B ALTER USER baduser@hostname MAX_USER_CONNECTIONS 0;
C ALTER USER baduser@hostname ACCOUNT LOCK;
D ALTER USER baduser@hostname IDENTIFIED WITH mysql_no_login;
E ALTER USER baduser@hostname DEFAULT ROLE NONE;
Answer: C, D
Explanation:
If a MySQL user account has been compromised, the immediate goal is to prevent the user from making any further connections. Several MySQL commands can be used to disable or lock the account to block new connections.
C (ALTER USER baduser@hostname ACCOUNT LOCK) is correct. The ACCOUNT LOCK option in MySQL will lock the user’s account, preventing any new connections from that account, regardless of the user's credentials. This action immediately blocks access to the compromised account, preventing further misuse.
D (ALTER USER baduser@hostname IDENTIFIED WITH mysql_no_login) is correct. The mysql_no_login authentication plugin effectively disables the account, preventing the user from logging in. This is another way to immediately block new connections while retaining the user account for potential investigation or recovery.
A (ALTER USER baduser@hostname PASSWORD DISABLED) is incorrect. The PASSWORD DISABLED option only disables the password but does not necessarily prevent the user from authenticating if they have a valid session or if other authentication methods (e.g., socket authentication) are used. It doesn't immediately block new connections as effectively as the other options.
B (ALTER USER baduser@hostname MAX_USER_CONNECTIONS 0) is incorrect. Setting MAX_USER_CONNECTIONS to 0 will prevent the user from making multiple connections, but it doesn't immediately block new connections. This setting only limits the number of concurrent connections a user can make, which could still allow a single connection to be established.
E (ALTER USER baduser@hostname DEFAULT ROLE NONE) is incorrect. This command assigns a user no roles, which would limit the user's access, but it does not immediately block connections. The user might still be able to connect if their account is not locked or disabled.
To immediately block new connections from a compromised user account, the ACCOUNT LOCK and mysql_no_login options are the most effective. Therefore, the correct answers are C and D.
Question 3
You are running MySQL 8 with asynchronous replication and want to switch to GTID-based replication. Which two actions are required to complete this transition? (Select two.)
A On both master and slave, execute: SET GLOBAL GTID_ENABLED=on;
B On the slave, run: START SLAVE IO_THREAD WITH GTID;
C Restart both servers with these options: --gtid_mode=ON, --log-bin, --log-slave-updates, --enforce-gtid-consistency
D On the slave, use: RESET SLAVE; START SLAVE GTID_NEXT=AUTOMATIC;
E On the slave, use: ALTER CHANNEL CHANGE MASTER TO MASTER_AUTO_POSITION = 1;
F On the slave, use: CHANGE MASTER TO MASTER_AUTO_POSITION = 1;
Answer: C, F
Explanation:
To switch from asynchronous replication to GTID-based replication in MySQL 8, there are several steps that need to be followed. The transition to GTID (Global Transaction Identifiers) replication requires enabling GTID support, configuring the server properly, and ensuring that both the master and slave are properly set up to support GTIDs.
C (Restart both servers with these options: --gtid_mode=ON, --log-bin, --log-slave-updates, --enforce-gtid-consistency) is correct. These server options must be set in both the master and slave to enable GTID-based replication. Specifically:
--gtid_mode=ON enables GTID support.
--log-bin ensures that binary logging is enabled, which is necessary for replication.
--log-slave-updates enables the slave to log changes to its own binary log.
--enforce-gtid-consistency ensures that transactions are consistent and follow GTID rules, preventing the slave from applying inconsistent transactions.
F (On the slave, use: CHANGE MASTER TO MASTER_AUTO_POSITION = 1;) is correct. In GTID-based replication, MASTER_AUTO_POSITION = 1 tells the slave to automatically start replication from the GTID position stored in the master's binary log. This is a key step in setting up the slave to replicate based on GTID positions rather than using traditional replication with log file and position.
A (On both master and slave, execute: SET GLOBAL GTID_ENABLED=on;) is incorrect. The GTID_ENABLED variable is not a valid setting in MySQL 8. In fact, GTID is enabled by setting the --gtid_mode=ON parameter, which is done at the server start-up level, not via SET GLOBAL.
B (On the slave, run: START SLAVE IO_THREAD WITH GTID;) is incorrect. While it may seem logical to configure the slave with GTID-based replication on the IO_THREAD, the correct approach for enabling GTID replication is to use MASTER_AUTO_POSITION = 1, as noted in F.
D (On the slave, use: RESET SLAVE; START SLAVE GTID_NEXT=AUTOMATIC;) is incorrect. The command START SLAVE GTID_NEXT=AUTOMATIC; is used to handle GTID position when starting the slave, but RESET SLAVE is unnecessary in this context unless you are resetting replication completely. The GTID_NEXT setting is not a typical command for enabling GTID replication from the beginning.
E (On the slave, use: ALTER CHANNEL CHANGE MASTER TO MASTER_AUTO_POSITION = 1;) is incorrect. While CHANGE MASTER TO MASTER_AUTO_POSITION is correct, the ALTER CHANNEL syntax is not the appropriate command to use for GTID-based replication setup. The correct syntax is as in F.
In conclusion, the correct actions to complete the transition to GTID-based replication in MySQL 8 are C and F.
Question 4
Which four protocols can MySQL clients use with the --protocol option to specify how they connect to the server? (Select four.)
A TCP
B SOCKET
C PIPE
D DIRECT
E IPv6
F FILE
G IPv4
H MEMORY
Answer: A, B, C, G
Explanation:
MySQL clients can specify different connection protocols using the --protocol option to determine how they connect to the MySQL server. The following are valid options:
A (TCP) is correct. TCP is one of the most common network protocols used by MySQL clients to communicate with the MySQL server. This is typically used when the client and server are on different machines or the connection is over a network.
B (SOCKET) is correct. The SOCKET protocol allows MySQL clients to connect to the MySQL server using a local Unix socket file, which is often used when the MySQL server and the client reside on the same machine. This protocol can be more efficient than TCP for local connections.
C (PIPE) is correct. The PIPE protocol allows MySQL clients to connect using named pipes, which are often used in Windows environments. Named pipes provide an inter-process communication mechanism for connecting to the MySQL server locally without using network-based protocols.
G (IPv4) is correct. IPv4 is a network protocol used for communication over IP networks and is the most common protocol used for internet-based or intranet-based connections. MySQL clients can connect to the server over IPv4 if the server is configured for it.
D (DIRECT) is incorrect. The DIRECT protocol is not a valid connection protocol for MySQL clients. This is not a supported option for connection to the MySQL server.
E (IPv6) is incorrect. While MySQL does support IPv6 for network connections, the --protocol option does not specifically use "IPv6" as a keyword. Rather, it uses TCP or Unix Socket/other supported protocols, and the MySQL server must be configured to support IPv6 for it to function properly.
F (FILE) is incorrect. FILE is not a valid connection protocol for MySQL clients. The FILE option is used for loading data from external files into MySQL, but it is not a connection protocol.
H (MEMORY) is incorrect. MEMORY is not a valid protocol used for MySQL client-server communication. The MEMORY option refers to storage engines and is unrelated to connection protocols.
In conclusion, the four valid connection protocols for MySQL clients are TCP, SOCKET, PIPE, and IPv4. Therefore, the correct answers are A, B, C, and G.
Question 5
Which three statements about MySQL replication are accurate? (Select three.)
A Only TCP/IP can be used for replication connections.
B A server can have many slaves, but only one master.
C Every server in a replication setup needs a unique server ID.
D Binary logs record transactions from only one MySQL instance.
E Each slave must use a different replication user.
F Binary logging is required on the master server.
G The replication user must have SELECT permissions on all replicated tables.
Answer: C, D, F
Explanation:
MySQL replication allows for the synchronization of data between a master server and one or more slave servers. Several important points must be considered when configuring replication, and the following statements are correct:
C (Every server in a replication setup needs a unique server ID) is correct. Each MySQL server in a replication setup, whether master or slave, must have a unique server ID. This helps to distinguish between the servers during replication and ensures that GTID-based or position-based replication functions properly.
D (Binary logs record transactions from only one MySQL instance) is correct. The binary logs on a MySQL master record all changes to the database. These logs are then replicated to the slave servers. Each master server has its own binary log, and the slave servers use it to keep in sync. Each binary log file is specific to a single MySQL instance, meaning multiple masters cannot share a binary log.
F (Binary logging is required on the master server) is correct. Binary logging must be enabled on the master server for replication to work. The binary log records every change to the database, which is then sent to the slave servers to maintain synchronization.
The following statements are incorrect for the following reasons:
A (Only TCP/IP can be used for replication connections) is incorrect. While TCP/IP is the most common protocol for replication, Unix sockets can also be used for local replication on Linux or Unix-based systems. MySQL allows replication connections using either TCP/IP or Unix sockets (when the master and slave are on the same machine).
B (A server can have many slaves, but only one master) is incorrect. A master can indeed have multiple slaves, but the reverse is also true: a slave can replicate from multiple masters in certain scenarios, such as multi-master replication. This does not limit replication to a one-to-one master-slave relationship.
E (Each slave must use a different replication user) is incorrect. While it is generally a best practice to use different replication users for security reasons, it is not a requirement. A single replication user can be used across multiple slaves, as long as the user has the necessary replication privileges.
G (The replication user must have SELECT permissions on all replicated tables) is incorrect. The replication user does not need SELECT permissions on all tables. The replication user needs REPLICATION SLAVE privileges (or equivalent) to read from the master's binary log and replicate the changes to the slave, but it does not require direct SELECT privileges on all the tables being replicated.
Question 6
Which two statements correctly describe the mysql_config_editor utility? (Select two.)
A It is used to configure MySQL Firewall settings.
B It stores login credentials for MySQL client programs.
C It can relocate the data directory.
D It manages user privilege configurations.
E It defaults to using the [client] group unless --login-path is specified.
F It creates and modifies SSL certificates and log paths.
G It serves as a tool to edit the my.cnf configuration file.
Answer: B, E
Explanation:
The mysql_config_editor utility is a command-line tool that helps to securely store and manage login credentials for MySQL client programs. The following points accurately describe its function:
B (It stores login credentials for MySQL client programs) is correct. The primary purpose of mysql_config_editor is to store login credentials securely for MySQL client programs. It allows you to store username, password, host, and other connection information in an encrypted format. This makes it easier and more secure for clients to connect to MySQL without exposing credentials in plaintext.
E (It defaults to using the [client] group unless --login-path is specified) is correct. By default, mysql_config_editor uses the [client] group in the configuration file. This group holds default login information for MySQL client programs like mysql, mysqldump, etc. However, the --login-path option can be used to specify a different login path if needed, allowing for different sets of credentials for different client programs.
The following statements are incorrect for the following reasons:
A (It is used to configure MySQL Firewall settings) is incorrect. mysql_config_editor is not used for configuring MySQL Firewall settings. Its purpose is solely to store login credentials for MySQL client programs.
C (It can relocate the data directory) is incorrect. mysql_config_editor does not have any functionality related to relocating the data directory. Changing the data directory requires altering configuration files like my.cnf or my.ini.
D (It manages user privilege configurations) is incorrect. mysql_config_editor does not manage user privileges. Privileges are managed via MySQL’s GRANT statement or within the MySQL Workbench.
F (It creates and modifies SSL certificates and log paths) is incorrect. mysql_config_editor does not handle SSL certificates or modify log paths. It is only focused on storing MySQL connection credentials.
G (It serves as a tool to edit the my.cnf configuration file) is incorrect. mysql_config_editor is not used to edit the my.cnf configuration file. The my.cnf file is typically edited manually or via other tools like MySQL Workbench or command-line editors.
In conclusion, B and E are the correct answers because mysql_config_editor is used to securely store login credentials and defaults to using the [client] group unless specified otherwise.
Question 7
Given the successful execution of the following command:
mysqldump --master-data=2 --single-transaction --result-file=dump.sql mydb
Which two statements are true regarding this backup operation? (Select two.)
A It performs a FLUSH TABLES WITH READ LOCK operation.
B It ensures backup consistency across all storage engines.
C The backup file represents a consistent snapshot of the data.
D The transaction uses the READ COMMITTED isolation level.
E This is considered an offline (cold) backup.
Answer: B, C
Explanation:
This command involves creating a consistent backup of the database using mysqldump. Here's the breakdown of the options:
B (It ensures backup consistency across all storage engines) is correct. The --single-transaction option ensures that the backup is taken at a consistent point in time by initiating a transaction. This ensures that the snapshot reflects the state of the database at that moment, even if changes are occurring concurrently. The single-transaction option is particularly important for InnoDB storage engines, which support ACID transactions, ensuring that data consistency is maintained across the backup.
C (The backup file represents a consistent snapshot of the data) is correct. With the --single-transaction flag, mysqldump ensures that the backup file is a consistent snapshot. InnoDB tables are consistent, and no changes are made to the database during the backup process. The --master-data=2 option also includes CHANGE MASTER TO information for setting up replication, which helps ensure the consistency of the backup when setting up replication later.
The following options are incorrect for the following reasons:
A (It performs a FLUSH TABLES WITH READ LOCK operation) is incorrect. The --single-transaction option prevents the need for a FLUSH TABLES WITH READ LOCK operation. FLUSH TABLES WITH READ LOCK is typically used in non-transactional engines or when --lock-tables is used, but with --single-transaction, this lock is not performed.
D (The transaction uses the READ COMMITTED isolation level) is incorrect. The --single-transaction option uses the REPEATABLE READ isolation level by default, not READ COMMITTED. REPEATABLE READ ensures that the transaction sees a consistent snapshot of the data throughout its execution.
E (This is considered an offline (cold) backup) is incorrect. An offline (cold) backup requires the database to be shut down or locked to ensure no data changes during the backup. However, the --single-transaction option performs an online (hot) backup, meaning the database remains available for use while the backup is being taken.
Question 8
You need to prevent a replica from falling too far behind its MySQL 8.0 primary during peak loads.
Which two replication settings can help minimize replica lag? (Choose 2.)
A Enable WRITESET parallelization on the replica (SET GLOBAL slave_preserve_commit_order = 1)
B Increase the replica’s slave_parallel_workers to a value greater than 0
C Set relay_log_recovery = ON on the replica
D Configure slave_parallel_type = ‘LOGICAL_CLOCK’ on the replica
E Enable sync_binlog = 1 on the primary
Answer: B, D
Explanation:
To minimize replica lag in a MySQL 8.0 replication setup, you need to focus on parallel replication and other optimizations that help the replica keep up with the changes from the primary server. Let's break down the options:
B (Increase the replica’s slave_parallel_workers to a value greater than 0) is correct. By increasing the slave_parallel_workers, the replica can process multiple events in parallel, which helps reduce lag during periods of high load. This allows the replica to keep up with the primary by processing more than one transaction at a time, thus reducing the overall replication delay.
D (Configure slave_parallel_type = ‘LOGICAL_CLOCK’ on the replica) is correct. The slave_parallel_type configuration determines how the replica handles parallel replication. Setting it to LOGICAL_CLOCK allows the replica to process transactions in parallel in a more efficient manner, reducing lag and improving the overall throughput. This is especially beneficial when dealing with workloads that involve multiple parallel transactions.
The following options are incorrect for the following reasons:
A (Enable WRITESET parallelization on the replica (SET GLOBAL slave_preserve_commit_order = 1)) is incorrect. While WRITESET parallelization can help with specific types of workloads, it’s not a typical setting for preventing replica lag. Enabling slave_preserve_commit_order ensures that the order of writes in the parallel threads is preserved, but it doesn’t directly address replica lag in general workloads.
C (Set relay_log_recovery = ON on the replica) is incorrect. relay_log_recovery helps with recovery from relay log corruption and doesn’t directly address replication lag. It ensures that the relay log is properly recovered in the event of a failure, but it doesn’t prevent the replica from lagging behind the primary server.
E (Enable sync_binlog = 1 on the primary) is incorrect. While sync_binlog = 1 ensures that binary logs are safely written to disk, it’s primarily a safety feature rather than a performance optimization. It reduces the risk of data loss in the event of a crash, but it doesn’t directly help to reduce replication lag. It can actually slow down the primary server since it forces synchronous disk writes, which is more relevant for durability than performance in replication.
In conclusion, to minimize replication lag, B (Increase the replica’s slave_parallel_workers) and D (Configure slave_parallel_type = ‘LOGICAL_CLOCK’) are the most effective options. These settings improve parallel replication processing, which is key to minimizing delays on the replica.
Question 9
A DBA must perform an online, non-blocking schema change to add a NOT-NULL column with a default value to a 2-TB InnoDB table.
Which two MySQL 8.0 features accomplish this requirement with the least downtime? (Choose 2.)
A Instant ADD COLUMN (ALGORITHM = INSTANT)
B Online DDL with ALGORITHM = INPLACE, LOCK = NONE
C Clone Plugin to copy and modify the table on a spare instance
D Transportable Tablespaces to rebuild the table offline
E mysqlpump --single-transaction followed by rename-swap
Answer: A, B
Explanation:
In MySQL 8.0, performing schema changes on large tables like a 2-TB InnoDB table can be challenging because of the time and resources required. To minimize downtime, the following two options are best suited for online, non-blocking schema changes:
A (Instant ADD COLUMN (ALGORITHM = INSTANT)) is correct. Instant ADD COLUMN allows you to add a new column to a table without physically rewriting the table, which is typically the time-consuming part of schema changes. The new column can have a default value (including a NOT-NULL constraint), and the operation happens almost instantly, without locking the table or causing downtime. This is the ideal method for adding a NOT-NULL column with a default value to large tables, as the schema change is applied with minimal impact on performance.
B (Online DDL with ALGORITHM = INPLACE, LOCK = NONE) is correct. This option allows schema changes to be made in place without locking the table. The ALGORITHM = INPLACE option means that the table does not need to be copied, and LOCK = NONE ensures there is no blocking on other operations while the schema change is taking place. This method works well for non-disruptive schema changes, and MySQL 8.0 has optimized it for large tables to reduce downtime significantly.
The other options are less optimal:
C (Clone Plugin to copy and modify the table on a spare instance) is not ideal for online schema changes. While the Clone Plugin allows for copying the table to another instance and modifying it, it involves creating a copy of the table and can cause downtime during the switch-over, which is not ideal for the minimal-downtime requirement.
D (Transportable Tablespaces to rebuild the table offline) involves rebuilding the table by exporting and importing tablespaces, which requires downtime and does not meet the goal of performing an online schema change with minimal downtime.
E (mysqlpump --single-transaction followed by rename-swap) uses mysqldump to export and import the data with a single transaction, but this process is not non-blocking and involves downtime. While it can work for backup and recovery scenarios, it is not efficient for real-time schema changes.
Question 10
You must encrypt only the credit-card column in a customer table while leaving other data readable.
Which two built-in MySQL 8.0 capabilities satisfy this requirement without third-party tools? (Choose 2.)
A Define the column with the data type VARBINARY and encrypt/decrypt in application code using AES_ENCRYPT()/AES_DECRYPT()
B Create a Generated Column that stores AES_ENCRYPT(credit_card, master_key) and hide the base column with column-level privileges
C Enable InnoDB Tablespace Encryption with a keyring plugin
D Use Transparent Data Encryption (TDE) with per-table keys and selective column masking
E Create a VIEW that applies AES_DECRYPT() for authorized users, while revoking direct table access
Answer: A, E
Explanation:
In MySQL 8.0, to encrypt only specific columns like the credit-card column while leaving other data readable, the following two methods are appropriate:
A (Define the column with the data type VARBINARY and encrypt/decrypt in application code using AES_ENCRYPT()/AES_DECRYPT()) is correct. This approach uses AES encryption directly within MySQL through the functions AES_ENCRYPT() and AES_DECRYPT(). The column is defined with the VARBINARY data type to store the encrypted data. The actual encryption and decryption process are handled at the application level, where the credit card data is encrypted before insertion into the table and decrypted when retrieved. This method ensures that only the specific column is encrypted and that other data remains accessible in its readable form.
E (Create a VIEW that applies AES_DECRYPT() for authorized users, while revoking direct table access) is correct. Another approach involves creating a view that uses AES_DECRYPT() to decrypt the credit card column for authorized users. In this setup, the VIEW provides the decrypted data for those who have appropriate access while the underlying table stores the encrypted data. By restricting direct access to the table and using a view for authorized users, this solution provides column-level encryption without affecting other data. The use of revoke on the base table further ensures that unauthorized users cannot access the encrypted data directly.
The other options are less suitable:
B (Create a Generated Column that stores AES_ENCRYPT(credit_card, master_key) and hide the base column with column-level privileges) is incorrect because while a generated column can be used to store encrypted values, the master_key must be handled securely. This method would still require application-level decryption, and it’s not as flexible as using a view to handle user access control for encryption and decryption.
C (Enable InnoDB Tablespace Encryption with a keyring plugin) is not suitable for encrypting a single column. InnoDB Tablespace Encryption encrypts entire tablespaces, not individual columns. Therefore, it would encrypt all data in the table, not just the credit card information, making it inappropriate for column-specific encryption.
D (Use Transparent Data Encryption (TDE) with per-table keys and selective column masking) is not a feature available in MySQL 8.0. TDE (Transparent Data Encryption) is typically available in some enterprise editions of databases like SQL Server and Oracle, but MySQL 8.0 does not support TDE with column-level masking. In MySQL, the built-in encryption options focus on whole-tables or tablespaces, not individual columns.
Thus, the best solutions for encrypting only the credit-card column are A and E.
