[2024年11月06日] 無料MySQL Database Administration 1z0-915-1試験問題を使おう
1z0-915-1問題集でMySQL Database Administration必ず合格できる練習問題集
質問 # 28
What must you do to minimize a DB system down time caused by automatic maintenance operations?
- A. Add HeatWave cluster.
- B. Enable crash recovery.
- C. Create read replicas.
- D. Enable high availability.
正解：D
解説：
To minimize DB system downtime caused by automatic maintenance operations, you should enable high availability. High availability ensures that there are multiple instances of your database running in different fault domains or availability domains, reducing the impact of maintenance on the system's availability.
質問 # 29
You want to replicate data from an on-premises MySQL server to a MySQL DB system. The on-premises MySQL server runs in your corporate network. The MySQL server accepts incoming connections from the Internet on a public IP endpoint.
The DB system runs in Oracle Cloud Infrastructure. The DB system endpoint is connected to a privatesubnet of a VCN.
Which network configuration is required?
- A. Create a service gateway in the VCN and configure the DB system subnet to route Internet-bound traffic to the service gateway.
- B. Create an Internet gateway in the VCN and configure the DB system subnet to route Internet-bound traffic to the Internet gateway.
- C. Configure an OCI network load balancer to accept incoming connections on a public IP and route to the DB system private IP address.
- D. Create a NAT gateway in the VCN and configure the DB system subnet to route Internet-bound traffic to the NAT gateway.
正解：D
解説：
To replicate data from an on-premises MySQL server to a MySQL DB system running in Oracle Cloud Infrastructure (OCI), where the DB system is connected to a private subnet of a Virtual Cloud Network (VCN), you need to enable the DB system to communicate with the Internet securely. The correct configuration is tocreate a NAT gateway in the VCN and configure the DB system subnet to route Internet-bound traffic to the NAT gateway(Answer D).
* NAT Gateway: A Network Address Translation (NAT) gateway enables instances in a private subnet to initiate outbound traffic to the Internet, but it prevents the Internet from initiating connections to those instances.
* Route Table Configuration: You need to update the route table for the private subnet to direct traffic destined for the Internet to the NAT gateway.
Steps:
* Create a NAT gateway in the OCI Console.
* Update the route table associated with the private subnet to include a route rule that directs all Internet-bound traffic (0.0.0.0/0) to the NAT gateway.
References:
* OCI NAT Gateway Documentation
* Configuring Routing for Private Subnets
質問 # 30
You want to change the configuration of an active stand-alone DB system. The DB system is configured as the target of a channel, and the channel is currently active.
Which sequence of steps must you perform?
- A. Delete the channel, edit the DB system, change the configuration, and re-create the channel.
- B. Edit the DB system and change the configuration.
- C. Stop the DB system, edit the DB system, change the configuration, and start the DB system.
- D. Stop the channel, edit the DB system, change the configuration, and start the channel.
正解：D
解説：
To change the configuration of an active stand-alone DB system that is configured as the target of a channel, and the channel is currently active, you must:
D:Stop the channel, edit the DB system, change the configuration, and start the channel: This sequence ensures that no data inconsistency or replication issues occur while the configuration changes are being applied.
質問 # 31
Why would you select "Source cannot use GTID auto-positioning" when creating a channel?
- A. The target DB system is a high-availability DB system.
- B. Some tables have no primary key
- C. The binary log offset is unknown.
- D. The source gtid mode is OFF.
正解：D
解説：
When creating a replication channel and selecting "Source cannot use GTID auto-positioning", it typically indicates that the source's GTID mode is off. GTID (Global Transaction Identifier) auto-positioning allows for automated recovery and positioning of transactions in replication, but it requires that GTID mode be enabled on the source database.
質問 # 32
You want to migrate an on-premises MySQL database to a MySQL DB system on OCI.
Which method provides the least amount of application down time when switching to the DB system?
- A. Run MySQL Shell on an OCI compute instance to export and import the data for faster migration.
- B. Use inbound replication to synchronize the MySQL database transactions to the DB system.
- C. Store the exported data in object storage to speed up the export and import.
- D. Use the largest DB system shape to speed up the import.
正解：B
解説：
To migrate an on-premises MySQL database to a MySQL DB system on OCI with the least amount of application downtime,use inbound replication to synchronize the MySQL database transactions to the DB system(Answer C).
* Inbound Replication: This method involves setting up replication from your on-premises MySQL database to the MySQL DB system in OCI. This ensures that all changes and transactions are continuously replicated, keeping the DB system up to date with minimal downtime.
* Steps to Implement:
* Set up the MySQL DB system in OCI.
* Configure the on-premises MySQL database as the master and the OCI DB system as the slave.
* Start the replication process to keep the DB system synchronized with the on-premises database.
* When ready, switch the application to the DB system with minimal downtime as the data is already synchronized.
References:
* MySQL Replication Documentation
* OCI MySQL Database Service Replication
質問 # 33
The following statements execute successfully:
CALL sys.ML_TRAIN('ml_data.iris', 'class', NULL, @model);
SELECT @model;
Which three are true? (Choose three.)
- A. The generated model handle is shown in the output.
- B. The target column is class.
- C. The statements create a classification model.
- D. The statements validate the data set but do not create a model.
- E. The training data set is obtained from the ml_data table in the iris schema.
正解：A、B、C
解説：
The statementsCALL sys.ML_TRAIN('ml_data.iris', 'class', NULL, @model);andSELECT @model;are used to create and retrieve a machine learning model in MySQL HeatWave AutoML. The following are true:
* The generated model handle is shown in the output(Answer B): After training the model, the handle (identifier) for the model is stored in the@modelvariable and can be retrieved with theSELECT
@model;statement.
* The statements create a classification model(Answer C): TheML_TRAINprocedure is used to create a classification model since the target column (class) indicates a classification problem.
* The target column is class(Answer E): The second argument in theML_TRAINcall specifies the target column for the machine learning model, which isclassin this case.
References:
* MySQL HeatWave AutoML Documentation
* ML_TRAIN Procedure Documentation
質問 # 34
A port-forwarding Bastion session has been created for a MySQL DB system listening on 10.10.1.187:3306.
The SSH command provided by the Bastion session is:
An SSH tunnel is created successfully on a client machine by running this command:
Which command connects to the MySQL DB System from the client machine?
- A. mysqlsh mysql://[email protected]:3306
- B. mysqlsh mysql://[email protected]:3311
- C. mysqlsh mysql://[email protected]:3306
- D. mysqlsh mysql://[email protected]:3311
正解：B
解説：
Given the SSH command sets up port forwarding from the local port3311to the remote MySQL DB system port3306, the correct command to connect to the MySQL DB system from the client machine is:
C:mysqlsh mysql://[email protected]:3311
This command connects to the local machine's port3311, which forwards the connection to the MySQL DB system at10.10.1.187:3306.
質問 # 35
You have obtained a new tenancy on Oracle Cloud Infrastructure. You first create a VCN by using the VCN Wizard, and then create a MySQL DB system. You want to create a Connection in Database tools to use the SQL Worksheet feature.
Which three steps are required? (Choose three.)
- A. Create an OCI secret.
- B. Create an OCI vault.
- C. Import an X.509 certificate into the OCI vault.
- D. Create an OCI password.
- E. Create an encryption key.
正解：A、C、D
解説：
To create a connection in Database Tools to use the SQL Worksheet feature, the following steps are required:
* Create an OCI password(Answer A): This password is necessary for authentication when connecting to the MySQL DB system.
* Create an OCI secret(Answer D): Secrets are used to store sensitive information like passwords securely. The secret will contain the database credentials.
* Import an X.509 certificate into the OCI vault(Answer E): This certificate is required for secure connections to the database, ensuring encrypted communication.
References:
* OCI Database Tools Documentation
* Using OCI Secrets
* X.509 Certificates Documentation
質問 # 36
You want to train a classification model with MySQL HeatWave AutoML. Which two are requirements of the training data set? (Choose two.)
- A. The target column must have at least two distinct values.
- B. All feature columns must be numeric.
- C. There must be at least two feature columns.
- D. The target column and all feature columns must be stored in a single table.
- E. The target column must be numeric.
正解：A、D
解説：
When training a classification model with MySQL HeatWave AutoML, the following requirements must be met:
* The target column and all feature columns must be stored in a single table(Answer B): All data necessary for training the model should be in one table to simplify the data processing and training pipeline.
* The target column must have at least two distinct values(Answer E): For classification tasks, the target column must have multiple distinct values to enable the model to differentiate between classes.
References:
* MySQL HeatWave AutoML Documentation
* MySQL HeatWave User Guide
質問 # 37
What is the benefit of creating a new DB system with data import?
- A. Consistent data with no user connection
- B. Faster import with minimal logging
- C. Smaller storage size with better compression
- D. Faster backup with a first full backup
正解：B
解説：
Creating a new DB system with data import provides the benefit of faster import with minimal logging. This process is optimized to import large datasets efficiently and quickly, reducing the amount of logging overhead and ensuring a rapid setup of the new DB system.
質問 # 38
You want to connect to a DB system with MySQL Shell.
DB system endpoint IP address: 10.0.1.221
Username: admin
Password: MySQL8.0
Which two commands work? (Choose two.)
- A. mysqlsh mysql://MySQL8.0:[email protected]
- B. mysqlsh -host 10.0.1.221 -user admin -password MySQL8.0
- C. mysqlsh mysql://admin:[email protected]
- D. mysqlsh -h 10.0.1.221 -u admin -p MySQL8.0
- E. mysqlsh -h10.0.1.221 -uadmin -pMySQL8.0
正解：C、E
解説：
To connect to a MySQL DB system using MySQL Shell, you can use several command-line formats. Here, we will analyze the provided options:
A:mysqlsh -h 10.0.1.221 -u admin -p MySQL8.0
* Incorrect format. The password should not be directly placed after the-pflag without a space or equals sign.
B:mysqlsh mysql://MySQL8.0:[email protected]
* Incorrect format. The username should come before the password in the URL.
C:mysqlsh mysql://admin:[email protected]
* Correct format. This is a valid way to connect using a URL-like format whereadminis the username,MySQL8.0is the password, and10.0.1.221is the host.
D:mysqlsh -h10.0.1.221 -uadmin -pMySQL8.0
* Correct format. This is a valid way to connect using flags, with no spaces between the flags and their values.
E:mysqlsh -host 10.0.1.221 -user admin -password MySQL8.0
* Incorrect format. MySQL Shell uses-h,-u, and-pfor specifying host, username, and password respectively.
質問 # 39
Which two are true about read replica load balancer? (Choose two.)
- A. It distributes connections among the source DB system and all read replicas.
- B. It is created when the DB system is first created.
- C. It has the same endpoint as the DB system.
- D. User accounts containing a client host name cannot connect to the read replica load balancer.
- E. It distributes connections among read replicas.
正解：A、E
解説：
The following are true about the read replica load balancer:
* It distributes connections among the source DB system and all read replicas(Answer B): The load balancer distributes incoming read traffic across all read replicas and the source DB system to balance the load and improve performance.
* It distributes connections among read replicas(Answer E): The load balancer ensures that read traffic is evenly distributed among all available read replicas, providing high availability and scalability for read operations.
References:
* OCI MySQL Database Service Read Replicas Documentation
質問 # 40
You want to deploy a high-availability MySQL DB system in a region with multiple availability domains.
Which two types of subnet provide maximum redundancy? (Choose two.)
- A. A public regional subnet
- B. A public AD-specific subnet
- C. A private AD-specific subnet
- D. A private regional subnet
正解：A、D
解説：
To deploy a high-availability MySQL DB system in a region with multiple availability domains, the following types of subnets provide maximum redundancy:
* A private regional subnet(Answer B): This type of subnet spans all availability domains in the region, ensuring high availability and fault tolerance.
* A public regional subnet(Answer C): Similar to the private regional subnet, a public regional subnet spans all availability domains, providing maximum redundancy and accessibility.
References:
* OCI Networking Documentation
* MySQL High Availability Documentation
質問 # 41
Which MySQL HeatWave AutoML routine evaluates a model?
- A. ML_EXPLAIN
- B. ML_PREDICT_TABLE
- C. ML_SCORE
- D. ML_TRAIN
- E. ML_EXPLAIN_TABLE
正解：C
解説：
The MySQL HeatWave AutoML routine that evaluates a model isML_SCORE. This routine scores a trained machine learning model on a new dataset and evaluates its performance.
質問 # 42
Which placement is NOT valid for a high-availability DB system? (Note: AD refers to availability domain and FD refers to fault domain.)
- A. Primary instance: AD1-FD3; Secondary instance 1: AD2-FD2; Secondary instance 2: AD3-FD3
- B. Primary instance: AD1-FD1; Secondary instance 1: AD2-FD2; Secondary instance 2: AD3-FD3
- C. Primary instance: AD1-FD3; Secondary instance 1: AD1-FD2; Secondary instance 2: AD1-FD3
- D. Primary instance: AD1-FD1; Secondary instance 1: AD1-FD2; Secondary instance 2: AD1-FD3
正解：C
解説：
In a high-availability DB system, the placement of primary and secondary instances should ensure redundancy across different availability domains (ADs) and fault domains (FDs) to minimize downtime and data loss. The placement mentioned in option D is not valid because itplaces the primary and secondary instances in the same availability domain and fault domain, which does not provide high availability.
質問 # 43
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Oracle 1z0-915-1 認定試験の出題範囲：
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