DBS-C01 : AWS Certified Database – Specialty : Part 07

DBS-C01 : AWS Certified Database – Specialty : Part 07

1. A company is developing a new web application. An AWS CloudFormation template was created as a part of the build process.

   Recently, a change was made to an AWS::RDS::DBInstance resource in the template. The CharacterSetName property was changed to allow the application to process international text. A change set was generated using the new template, which indicated that the existing DB instance should be replaced during an upgrade.

   What should a database specialist do to prevent data loss during the stack upgrade?

   • Create a snapshot of the DB instance. Modify the template to add the DBSnapshotIdentifier property with the ID of the DB snapshot. Update the stack.
   • Modify the stack policy using the aws cloudformation update-stack command and the set-stack-policy command, then make the DB resource protected.
   • Create a snapshot of the DB instance. Update the stack. Restore the database to a new instance.
   • Deactivate any applications that are using the DB instance. Create a snapshot of the DB instance. Modify the template to add the DBSnapshotIdentifier property with the ID of the DB snapshot. Update the stack and reactivate the applications.

2. A company recently acquired a new business. A database specialist must migrate an unencrypted 12 TB Amazon RDS for MySQL DB instance to a new AWS account. The database specialist needs to minimize the amount of time required to migrate the database.

   Which solution meets these requirements?

   • Create a snapshot of the source DB instance in the source account. Share the snapshot with the destination account. In the target account, create a DB instance from the snapshot.
   • Use AWS Resource Access Manager to share the source DB instance with the destination account. Create a DB instance in the destination account using the shared resource.
   • Create a read replica of the DB instance. Give the destination account access to the read replica. In the destination account, create a snapshot of the shared read replica and provision a new RDS for MySQL DB instance.
   • Use mysqldump to back up the source database. Create an RDS for MySQL DB instance in the destination account. Use the mysql command to restore the backup in the destination database.

3. A company has applications running on Amazon EC2 instances in a private subnet with no internet connectivity. The company deployed a new application that uses Amazon DynamoDB, but the application cannot connect to the DynamoDB tables. A developer already checked that all permissions are set correctly.

   What should a database specialist do to resolve this issue while minimizing access to external resources?

   • Add a route to an internet gateway in the subnet’s route table.
   • Add a route to a NAT gateway in the subnet’s route table.
   • Assign a new security group to the EC2 instances with an outbound rule to ports 80 and 443.
   • Create a VPC endpoint for DynamoDB and add a route to the endpoint in the subnet’s route table.

4. The Amazon CloudWatch metric for FreeLocalStorage on an Amazon Aurora MySQL DB instance shows that the amount of local storage is below 10 MB. A database engineer must increase the local storage available in the Aurora DB instance.

   How should the database engineer meet this requirement?

   • Modify the DB instance to use an instance class that provides more local SSD storage.
   • Modify the Aurora DB cluster to enable automatic volume resizing.
   • Increase the local storage by upgrading the database engine version.
   • Modify the DB instance and configure the required storage volume in the configuration section.

5. A company has an ecommerce web application with an Amazon RDS for MySQL DB instance. The marketing team has noticed some unexpected updates to the product and pricing information on the website, which is impacting sales targets. The marketing team wants a database specialist to audit future database activity to help identify how and when the changes are being made.

   What should the database specialist do to meet these requirements? (Choose two.)

   • Create an RDS event subscription to the audit event type.
   • Enable auditing of CONNECT and QUERY_DML events.
   • SSH to the DB instance and review the database logs.
   • Publish the database logs to Amazon CloudWatch Logs.
   • Enable Enhanced Monitoring on the DB instance.

6. A large gaming company is creating a centralized solution to store player session state for multiple online games. The workload required key-value storage with low latency and will be an equal mix of reads and writes. Data should be written into the AWS Region closest to the user across the games’ geographically distributed user base. The architecture should minimize the amount of overhead required to manage the replication of data between Regions.

   Which solution meets these requirements?

   • Amazon RDS for MySQL with multi-Region read replicas
   • Amazon Aurora global database
   • Amazon RDS for Oracle with GoldenGate
   • Amazon DynamoDB global tables

7. A company is running an on-premises application comprised of a web tier, an application tier, and a MySQL database tier. The database is used primarily during business hours with random activity peaks throughout the day. A database specialist needs to improve the availability and reduce the cost of the MySQL database tier as part of the company’s migration to AWS.

   Which MySQL database option would meet these requirements?

   • Amazon RDS for MySQL with Multi-AZ
   • Amazon Aurora Serverless MySQL cluster
   • Amazon Aurora MySQL cluster
   • Amazon RDS for MySQL with read replica

8. A company wants to migrate its Microsoft SQL Server Enterprise Edition database instance from on-premises to AWS. A deep review is performed and the AWS Schema Conversion Tool (AWS SCT) provides options for running this workload on Amazon RDS for SQL Server Enterprise Edition, Amazon RDS for SQL Server Standard Edition, Amazon Aurora MySQL, and Amazon Aurora PostgreSQL. The company does not want to use its own SQL server license and does not want to change from Microsoft SQL Server.

   What is the MOST cost-effective and operationally efficient solution?

   • Run SQL Server Enterprise Edition on Amazon EC2.
   • Run SQL Server Standard Edition on Amazon RDS.
   • Run SQL Server Enterprise Edition on Amazon RDS.
   • Run Amazon Aurora MySQL leveraging SQL Server on Linux compatibility libraries.

9. A company’s ecommerce website uses Amazon DynamoDB for purchase orders. Each order is made up of a Customer ID and an Order ID. The DynamoDB table uses the Customer ID as the partition key and the Order ID as the sort key.

   To meet a new requirement, the company also wants the ability to query the table by using a third attribute named Invoice ID. Queries using the Invoice ID must be strongly consistent. A database specialist must provide this capability with optimal performance and minimal overhead.

   What should the database administrator do to meet these requirements?

   • Add a global secondary index on Invoice ID to the existing table.
   • Add a local secondary index on Invoice ID to the existing table.
   • Recreate the table by using the latest snapshot while adding a local secondary index on Invoice ID.
   • Use the partition key and a FilterExpression parameter with a filter on Invoice ID for all queries.

10. A company wants to migrate its on-premises MySQL databases to Amazon RDS for MySQL. To comply with the company’s security policy, all databases must be encrypted at rest. RDS DB instance snapshots must also be shared across various accounts to provision testing and staging environments.

    Which solution meets these requirements?

    • Create an RDS for MySQL DB instance with an AWS Key Management Service (AWS KMS) customer managed CMK. Update the key policy to include the Amazon Resource Name (ARN) of the other AWS accounts as a principal, and then allow the kms:CreateGrant action.
    • Create an RDS for MySQL DB instance with an AWS managed CMK. Create a new key policy to include the Amazon Resource Name (ARN) of the other AWS accounts as a principal, and then allow the kms:CreateGrant action.
    • Create an RDS for MySQL DB instance with an AWS owned CMK. Create a new key policy to include the administrator user name of the other AWS accounts as a principal, and then allow the kms:CreateGrant action.
    • Create an RDS for MySQL DB instance with an AWS CloudHSM key. Update the key policy to include the Amazon Resource Name (ARN) of the other AWS accounts as a principal, and then allow the kms:CreateGrant action.

11. A retail company manages a web application that stores data in an Amazon DynamoDB table. The company is undergoing account consolidation efforts. A database engineer needs to migrate the DynamoDB table from the current AWS account to a new AWS account.

    Which strategy meets these requirements with the LEAST amount of administrative work?

    • Use AWS Glue to crawl the data in the DynamoDB table. Create a job using an available blueprint to export the data to Amazon S3. Import the data from the S3 file to a DynamoDB table in the new account.
    • Create an AWS Lambda function to scan the items of the DynamoDB table in the current account and write to a file in Amazon S3. Create another Lambda function to read the S3 file and restore the items of a DynamoDB table in the new account.
    • Use AWS Data Pipeline in the current account to export the data from the DynamoDB table to a file in Amazon S3. Use Data Pipeline to import the data from the S3 file to a DynamoDB table in the new account.
    • Configure Amazon DynamoDB Streams for the DynamoDB table in the current account. Create an AWS Lambda function to read from the stream and write to a file in Amazon S3. Create another Lambda function to read the S3 file and restore the items to a DynamoDB table in the new account.

12. A company uses the Amazon DynamoDB table contractDB in us-east-1 for its contract system with the following schema:

    orderID (primary key)
    timestamp (sort key)
    contract (map)
    createdBy (string)
    customerEmail (string)

    After a problem in production, the operations team has asked a database specialist to provide an IAM policy to read items from the database to debug the application. In addition, the developer is not allowed to access the value of the customerEmail field to stay compliant.

    Which IAM policy should the database specialist use to achieve these requirements?

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    • 

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13. A company has an application that uses an Amazon DynamoDB table to store user data. Every morning, a single-threaded process calls the DynamoDB API Scan operation to scan the entire table and generate a critical start-of-day report for management. A successful marketing campaign recently doubled the number of items in the table, and now the process takes too long to run and the report is not generated in time.

    A database specialist needs to improve the performance of the process. The database specialist notes that, when the process is running, 15% of the table’s provisioned read capacity units (RCUs) are being used.

    What should the database specialist do?

    • Enable auto scaling for the DynamoDB table.
    • Use four threads and parallel DynamoDB API Scan operations.
    • Double the table’s provisioned RCUs.
    • Set the Limit and Offset parameters before every call to the API.

14. A company is building a software as a service application. As part of the new user sign-on workflow, a Python script invokes the CreateTable operation using the Amazon DynamoDB API. After the call returns, the script attempts to call PutItem.

    Occasionally, the PutItem request fails with a ResourceNotFoundException error, which causes the workflow to fail. The development team has confirmed that the same table name is used in the two API calls.

    How should a database specialist fix this issue?

    • Add an allow statement for the dynamodb:PutItem action in a policy attached to the role used by the application creating the table.
    • Set the StreamEnabled property of the StreamSpecification parameter to true, then call PutItem.
    • Change the application to call DescribeTable periodically until the TableStatus is ACTIVE, then call PutItem.
    • Add a ConditionExpression parameter in the PutItem request.

15. To meet new data compliance requirements, a company needs to keep critical data durably stored and readily accessible for 7 years. Data that is more than 1 year old is considered archival data and must automatically be moved out of the Amazon Aurora MySQL DB cluster every week. On average, around 10 GB of new data is added to the database every month. A database specialist must choose the most operationally efficient solution to migrate the archival data to Amazon S3.

    Which solution meets these requirements?

    • Create a custom script that exports archival data from the DB cluster to Amazon S3 using a SQL view, then deletes the archival data from the DB cluster. Launch an Amazon EC2 instance with a weekly cron job to execute the custom script.
    • Configure an AWS Lambda function that exports archival data from the DB cluster to Amazon S3 using a SELECT INTO OUTFILE S3 statement, then deletes the archival data from the DB cluster. Schedule the Lambda function to run weekly using Amazon EventBridge (Amazon CloudWatch Events).
    • Configure two AWS Lambda functions: one that exports archival data from the DB cluster to Amazon S3 using the mysqldump utility, and another that deletes the archival data from the DB cluster. Schedule both Lambda functions to run weekly using Amazon EventBridge (Amazon CloudWatch Events).
    • Use AWS Database Migration Service (AWS DMS) to continually export the archival data from the DB cluster to Amazon S3. Configure an AWS Data Pipeline process to run weekly that executes a custom SQL script to delete the archival data from the DB cluster.

16. A company developed a new application that is deployed on Amazon EC2 instances behind an Application Load Balancer. The EC2 instances use the security group named sg-application-servers. The company needs a database to store the data from the application and decides to use an Amazon RDS for MySQL DB instance. The DB instance is deployed in private DB subnet.

    What is the MOST restrictive configuration for the DB instance security group?

    • Only allow incoming traffic from the sg-application-servers security group on port 3306.
    • Only allow incoming traffic from the sg-application-servers security group on port 443.
    • Only allow incoming traffic from the subnet of the application servers on port 3306.
    • Only allow incoming traffic from the subnet of the application servers on port 443.

17. A company is moving its fraud detection application from on premises to the AWS Cloud and is using Amazon Neptune for data storage. The company has set up a 1 Gbps AWS Direct Connect connection to migrate 25 TB of fraud detection data from the on-premises data center to a Neptune DB instance. The company already has an Amazon S3 bucket and an S3 VPC endpoint, and 80% of the company’s network bandwidth is available.

    How should the company perform this data load?

    • Use an AWS SDK with a multipart upload to transfer the data from on premises to the S3 bucket. Use the Copy command for Neptune to move the data in bulk from the S3 bucket to the Neptune DB instance.
    • Use AWS Database Migration Service (AWS DMS) to transfer the data from on premises to the S3 bucket. Use the Loader command for Neptune to move the data in bulk from the S3 bucket to the Neptune DB instance.
    • Use AWS DataSync to transfer the data from on premises to the S3 bucket. Use the Loader command for Neptune to move the data in bulk from the S3 bucket to the Neptune DB instance.
    • Use the AWS CLI to transfer the data from on premises to the S3 bucket. Use the Copy command for Neptune to move the data in bulk from the S3 bucket to the Neptune DB instance.

18. A company migrated one of its business-critical database workloads to an Amazon Aurora Multi-AZ DB cluster. The company requires a very low RTO and needs to improve the application recovery time after database failovers.

    Which approach meets these requirements?

    • Set the max_connections parameter to 16,000 in the instance-level parameter group.
    • Modify the client connection timeout to 300 seconds.
    • Create an Amazon RDS Proxy database proxy and update client connections to point to the proxy endpoint.
    • Enable the query cache at the instance level.

19. A company is using an Amazon RDS for MySQL DB instance for its internal applications. A security audit shows that the DB instance is not encrypted at rest. The company’s application team needs to encrypt the DB instance.

    What should the team do to meet this requirement?

    • Stop the DB instance and modify it to enable encryption. Apply this setting immediately without waiting for the next scheduled RDS maintenance window.

    • Stop the DB instance and create an encrypted snapshot. Restore the encrypted snapshot to a new encrypted DB instance. Delete the original DB instance, and update the applications to point to the new encrypted DB instance.
    • Stop the DB instance and create a snapshot. Copy the snapshot into another encrypted snapshot. Restore the encrypted snapshot to a new encrypted DB instance. Delete the original DB instance, and update the applications to point to the new encrypted DB instance.
    • Create an encrypted read replica of the DB instance. Promote the read replica to master. Delete the original DB instance, and update the applications to point to the new encrypted DB instance.

20. A database specialist must create nightly backups of an Amazon DynamoDB table in a mission-critical workload as part of a disaster recovery strategy.

    Which backup methodology should the database specialist use to MINIMIZE management overhead?

    • Install the AWS CLI on an Amazon EC2 instance. Write a CLI command that creates a backup of the DynamoDB table. Create a scheduled job or task that executes the command on a nightly basis.
    • Create an AWS Lambda function that creates a backup of the DynamoDB table. Create an Amazon CloudWatch Events rule that executes the Lambda function on a nightly basis.
    • Create a backup plan using AWS Backup, specify a backup frequency of every 24 hours, and give the plan a nightly backup window.
    • Configure DynamoDB backup and restore for an on-demand backup frequency of every 24 hours.
    Explanation:
    On-demand backup allows you to create full backups of your Amazon DynamoDB table for data archiving, helping you meet your corporate and governmental regulatory requirements. You can back up tables from a few megabytes to hundreds of terabytes of data, with no impact on performance and availability to your production applications. Backups process in seconds regardless of the size of your tables, so you do not have to worry about backup schedules or long-running processes. In addition, all backups are automatically encrypted, cataloged, easily discoverable, and retained until explicitly deleted.