DBS-C01 Online Practice Questions and Answers

A company is using a Single-AZ Amazon RDS for MySQL DB instance for development. The DB instance is experiencing slow performance when queries are executed. Amazon CloudWatch metrics indicate that the instance requires more I/ O capacity.

Which actions can a database specialist perform to resolve this issue? (Choose two.)

A. Restart the application tool used to execute queries.

B. Change to a database instance class with higher throughput.

C. Convert from Single-AZ to Multi-AZ.

D. Increase the I/O parameter in Amazon RDS Enhanced Monitoring.

E. Convert from General Purpose to Provisioned IOPS (PIOPS).

A ride-hailing application uses an Amazon RDS for MySQL DB instance as persistent storage for bookings. This application is very popular and the company expects a tenfold increase in the user base in next few months. The application

experiences more traffic during the morning and evening hours.

This application has two parts:

An in-house booking component that accepts online bookings that directly correspond to simultaneous requests from users.

A third-party customer relationship management (CRM) component used by customer care representatives. The CRM uses queries to access booking data.

A database specialist needs to design a cost-effective database solution to handle this workload. Which solution meets these requirements?

A. Use Amazon ElastiCache for Redis to accept the bookings. Associate an AWS Lambda function to capture changes and push the booking data to the RDS for MySQL DB instance used by the CRM.

B. Use Amazon DynamoDB to accept the bookings. Enable DynamoDB Streams and associate an AWS Lambda function to capture changes and push the booking data to an Amazon SQS queue. This triggers another Lambda function that pulls data from Amazon SQS and writes it to the RDS for MySQL DB instance used by the CRM.

C. Use Amazon ElastiCache for Redis to accept the bookings. Associate an AWS Lambda function to capture changes and push the booking data to an Amazon Redshift database used by the CRM.

D. Use Amazon DynamoDB to accept the bookings. Enable DynamoDB Streams and associate an AWS Lambda function to capture changes and push the booking data to Amazon Athena, which is used by the CRM.

A business need a data warehouse system that stores data consistently and in a highly organized fashion. The organization demands rapid response times for end-user inquiries including current-year data, and users must have access to the whole 15-year dataset when necessary. Additionally, this solution must be able to manage a variable volume of incoming inquiries. Costs associated with storing the 100 TB of data must be maintained to a minimum.

Which solution satisfies these criteria?

A. Leverage an Amazon Redshift data warehouse solution using a dense storage instance type while keeping all the data on local Amazon Redshift storage. Provision enough instances to support high demand.

B. Leverage an Amazon Redshift data warehouse solution using a dense storage instance to store the most recent data. Keep historical data on Amazon S3 and access it using the Amazon Redshift Spectrum layer. Provision enough instances to support high demand.

C. Leverage an Amazon Redshift data warehouse solution using a dense storage instance to store the most recent data. Keep historical data on Amazon S3 and access it using the Amazon Redshift Spectrum layer. Enable Amazon Redshift Concurrency Scaling.

D. Leverage an Amazon Redshift data warehouse solution using a dense storage instance to store the most recent data. Keep historical data on Amazon S3 and access it using the Amazon Redshift Spectrum layer. Leverage Amazon Redshift elastic resize.

A company is building a new web platform where user requests trigger an AWS Lambda function that performs an insert into an Amazon Aurora MySQL DB cluster. Initial tests with less than 10 users on the new platform yielded successful execution and fast response times. However, upon more extensive tests with the actual target of 3,000 concurrent users, Lambda functions are unable to connect to the DB cluster and receive too many connections errors.

Which of the following will resolve this issue?

A. Edit the my.cnf file for the DB cluster to increase max_connections

B. Increase the instance size of the DB cluster

C. Change the DB cluster to Multi-AZ

D. Increase the number of Aurora Replicas

A company conducted a security audit of its AWS infrastructure. The audit identified that data was not encrypted in transit between application servers and a MySQL database that is hosted in Amazon RDS.

After the audit, the company updated the application to use an encrypted connection. To prevent this problem from occurring again, the company's database team needs to configure the database to require in-transit encryption for all connections.

Which solution will meet this requirement?

A. Update the parameter group in use by the DB instance, and set the require_secure_transport parameter to ON.

B. Connect to the database, and use ALTER USER to enable the REQUIRE SSL option on the database user.

C. Update the security group in use by the DB instance, and remove port 80 to prevent unencrypted connections from being established.

D. Update the DB instance, and enable the Require Transport Layer Security option.

A pharmaceutical company uses Amazon Quantum Ledger Database (Amazon QLDB) to store its clinical trial data records. The company has an application that runs as AWS Lambda functions. The application is hosted in the private subnet in a VPC.

The application does not have internet access and needs to read some of the clinical data records. The company is concerned that traffic between the QLDB ledger and the VPC could leave the AWS network. The company needs to secure access to the QLDB ledger and allow the VPC traffic to have read-only access.

Which security strategy should a database specialist implement to meet these requirements?

A. Move the QLDB ledger into a private database subnet inside the VPC. Run the Lambda functions inside the same VPC in an application private subnet. Ensure that the VPC route table allows read-only flow from the application subnet to the database subnet.

B. Create an AWS PrivateLink VPC endpoint for the QLDB ledger. Attach a VPC policy to the VPC endpoint to allow read-only traffic for the Lambda functions that run inside the VPC.

C. Add a security group to the QLDB ledger to allow access from the private subnets inside the VPC where the Lambda functions that access the QLDB ledger are running.

D. Create a VPN connection to ensure pairing of the private subnet where the Lambda functions are running with the private subnet where the QLDB ledger is deployed.

A social media company recently launched a new feature that gives users the ability to share live feeds of their daily activities with their followers. The company has an Amazon RDS for MySOL DB instance that stores data about follower engagement After the new feature launched, the company noticed high CPU utilization and high database latency during reads and writes. The company wants to implement a solution that will identify the source of the high CPU utilization.

Which solution will meet these requirements with the LEAST administrative oversight?

A. Use Amazon DevOps Guru insights_

B. Use AWS CloudTrail

C. Use Amazon CloudWatch Logs

D. Use Amazon Aurora Database Activity Streams

On a single Amazon RDS DB instance, a business hosts a MySQL database for its ecommerce application. Automatically saving application purchases to the database results in high-volume writes. Employees routinely create purchase reports for the company. The organization wants to boost database performance and minimize downtime associated with upgrade patching.

Which technique will satisfy these criteria with the LEAST amount of operational overhead?

A. Enable a Multi-AZ deployment of the RDS for MySQL DB instance, and enable Memcached in the MySQL option group.

B. Enable a Multi-AZ deployment of the RDS for MySQL DB instance, and set up replication to a MySQL DB instance running on Amazon EC2.

C. Enable a Multi-AZ deployment of the RDS for MySQL DB instance, and add a read replica.

D. Add a read replica and promote it to an Amazon Aurora MySQL DB cluster master. Then enable Amazon Aurora Serverless.

A financial services company is developing a shared data service that supports different applications from throughout the company. A Database Specialist designed a solution to leverage Amazon ElastiCache for Redis with cluster mode enabled to enhance performance and scalability. The cluster is configured to listen on port 6379.

Which combination of steps should the Database Specialist take to secure the cache data and protect it from unauthorized access? (Choose three.)

A. Enable in-transit and at-rest encryption on the ElastiCache cluster.

B. Ensure that Amazon CloudWatch metrics are configured in the ElastiCache cluster.

C. Ensure the security group for the ElastiCache cluster allows all inbound traffic from itself and inbound traffic on TCP port 6379 from trusted clients only.

D. Create an IAM policy to allow the application service roles to access all ElastiCache API actions.

E. Ensure the security group for the ElastiCache clients authorize inbound TCP port 6379 and port 22 traffic from the trusted ElastiCache cluster's security group.

F. Ensure the cluster is created with the auth-token parameter and that the parameter is used in all subsequent commands.

A database specialist wants to ensure that an Amazon Aurora DB cluster is always automatically upgraded to the most recent minor version available. Noticing that there is a new minor version available, the database specialist has issues an AWS CLI command to enable automatic minor version updates. The command runs successfully, but checking the Aurora DB cluster indicates that no update to the Aurora version has been made.

What might account for this? (Choose two.)

A. The new minor version has not yet been designated as preferred and requires a manual upgrade.

B. Configuring automatic upgrades using the AWS CLI is not supported. This must be enabled expressly using the AWS Management Console.

C. Applying minor version upgrades requires sufficient free space.

D. The AWS CLI command did not include an apply-immediately parameter.

E. Aurora has detected a breaking change in the new minor version and has automatically rejected the upgrade.