Amazon Amazon Certifications DBS-C01 Questions & Answers

• Question 251:

  A large IT hardware manufacturing company wants to deploy a MySQL database solution in the AWS Cloud. The solution should quickly create copies of the company's production databases for test purposes. The solution must deploy the test databases in minutes, and the test data should match the latest production data as closely as possible. Developers must also be able to make changes in the test database and delete the instances afterward.

  Which solution meets these requirements?

  A. Leverage Amazon RDS for MySQL with write-enabled replicas running on Amazon EC2. Create the test copies using a mysqidump backup from the RDS for MySQL DB instances and importing them into the new EC2 instances.

  B. Leverage Amazon Aurora MySQL. Use database cloning to create multiple test copies of the production DB clusters.

  C. Leverage Amazon Aurora MySQL. Restore previous production DB instance snapshots into new test copies of Aurora MySQL DB clusters to allow them to make changes.

  D. Leverage Amazon RDS for MySQL. Use database cloning to create multiple developer copies of the production DB instance.

  Correct Answer: B

• Question 252:

  An internet advertising firm stores its data in an Amazon DynamoDb table. Amazon DynamoDB Streams are enabled on the table, and one of the keys has a global secondary index. The table is encrypted using a customer-managed AWS

  Key Management Service (AWS KMS) key.

  The firm has chosen to grow worldwide and want to duplicate the database using DynamoDB global tables in a new AWS Region.

  An administrator observes the following upon review:

  No role with the dynamodb: CreateGlobalTable permission exists in the account. An empty table with the same name exists in the new Region where replication is desired.

  A global secondary index with the same partition key but a different sort key exists in the new Region where replication is desired.

  Which settings will prevent you from creating a global table or replica in the new Region? (Select two.)

  A. A global secondary index with the same partition key but a different sort key exists in the new Region where replication is desired.

  B. An empty table with the same name exists in the Region where replication is desired.

  C. No role with the dynamodb:CreateGlobalTable permission exists in the account.

  D. DynamoDB Streams is enabled for the table.

  E. The table is encrypted using a KMS customer managed key.

  Correct Answer: AB

• Question 253:

  A database specialist has been entrusted by an ecommerce firm with designing a reporting dashboard that visualizes crucial business KPIs derived from the company's primary production database running on Amazon Aurora. The dashboard should be able to read data within 100 milliseconds after an update.

  The Database Specialist must conduct an audit of the Aurora DB cluster's present setup and provide a cost-effective alternative. The solution must support the unexpected read demand generated by the reporting dashboard without impairing the DB cluster's write availability and performance.

  Which solution satisfies these criteria?

  A. Turn on the serverless option in the DB cluster so it can automatically scale based on demand.

  B. Provision a clone of the existing DB cluster for the new Application team.

  C. Create a separate DB cluster for the new workload, refresh from the source DB cluster, and set up ongoing replication using AWS DMS change data capture (CDC).

  D. Add an automatic scaling policy to the DB cluster to add Aurora Replicas to the cluster based on CPU consumption.

  Correct Answer: D

• Question 254:

  A company wants to migrate its existing on-premises Oracle database to Amazon Aurora PostgreSQL. The migration must be completed with minimal downtime using AWS DMS. A Database Specialist must validate that the data was migrated accurately from the source to the target before the cutover. The migration must have minimal impact on the performance of the source database.

  Which approach will MOST effectively meet these requirements?

  A. Use the AWS Schema Conversion Tool (AWS SCT) to convert source Oracle database schemas to the target Aurora DB cluster. Verify the datatype of the columns.

  B. Use the table metrics of the AWS DMS task created for migrating the data to verify the statistics for the tables being migrated and to verify that the data definition language (DDL) statements are completed.

  C. Enable the AWS Schema Conversion Tool (AWS SCT) premigration validation and review the premigration checklist to make sure there are no issues with the conversion.

  D. Enable AWS DMS data validation on the task so the AWS DMS task compares the source and target records, and reports any mismatches.

  Correct Answer: D

  Explanation: "To ensure that your data was migrated accurately from the source to the target, we highly recommend that you use data validation." https://docs.aws.amazon.com/dms/latest/userguide/CHAP_BestPractices.html

  Reference: https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Validating.html

• Question 255:

  A company's database specialist disabled TLS on an Amazon DocumentDB cluster to perform benchmarking tests. A few days after this change was implemented, a database specialist trainee accidentally deleted multiple tables. The database specialist restored the database from available snapshots. An hour after restoring the cluster, the database specialist is still unable to connect to the new cluster endpoint.

  What should the database specialist do to connect to the new, restored Amazon DocumentDB cluster?

  A. Change the restored cluster's parameter group to the original cluster's custom parameter group.

  B. Change the restored cluster's parameter group to the Amazon DocumentDB default parameter group.

  C. Configure the interface VPC endpoint and associate the new Amazon DocumentDB cluster.

  D. Run the syncInstances command in AWS DataSync.

  Correct Answer: A

  Explanation: You can't modify the parameter settings of the default parameter groups. You can use a DB parameter group to act as a container for engine configuration values that are applied to one or more DB instances. If you create a DB instance without specifying a DB parameter group, the DB instance uses a default DB parameter group. Each default DB parameter group contains database engine defaults and Amazon RDS system defaults. You can't modify the parameter settings of a default parameter group. Instead, you create your own parameter group where you choose your own parameter settings. Not all DB engine parameters can be changed in a parameter group that you create.

• Question 256:

  A Database Specialist is migrating an on-premises Microsoft SQL Server application database to Amazon RDS for PostgreSQL using AWS DMS. The application requires minimal downtime when the RDS DB instance goes live.

  What change should the Database Specialist make to enable the migration?

  A. Configure the on-premises application database to act as a source for an AWS DMS full load with ongoing change data capture (CDC)

  B. Configure the AWS DMS replication instance to allow both full load and ongoing change data capture (CDC)

  C. Configure the AWS DMS task to generate full logs to allow for ongoing change data capture (CDC)

  D. Configure the AWS DMS connections to allow two-way communication to allow for ongoing change data capture (CDC)

  Correct Answer: A

  "requires minimal downtime when the RDS DB instance goes live" in order to do CDC: "you must first ensure that ARCHIVELOG MODE is on to provide information to LogMiner. AWS DMS uses LogMiner to read information from the archive

  logs so that AWS DMS can capture changes"

  https://docs.aws.amazon.com/dms/latest/sbs/chap-oracle2postgresql.steps.configureoracle.html

  "If you want to capture and apply changes (CDC), then you also need the following privileges."

• Question 257:

  A company is running a website on Amazon EC2 instances deployed in multiple Availability Zones (AZs). The site performs a high number of repetitive reads and writes each second on an Amazon RDS for MySQL Multi- AZ DB instance with General Purpose SSD (gp2) storage. After comprehensive testing and analysis, a database specialist discovers that there is high read latency and high CPU utilization on the DB instance.

  Which approach should the database specialist to take to resolve this issue without changing the application?

  A. Implementing sharding to distribute the load to multiple RDS for MySQL databases.

  B. Use the same RDS for MySQL instance class with Provisioned IOPS (PIOPS) storage.

  C. Add an RDS for MySQL read replica.

  D. Modify the RDS for MySQL database class to a bigger size and implement Provisioned IOPS (PIOPS).

  Correct Answer: D

• Question 258:

  A gaming company is building a mobile game that will have as many as 25,000 active concurrent users in the first 2 weeks after launch. The game has a leaderboard that shows the 10 highest scoring players over the last 24 hours. The leaderboard calculations are processed by an AWS Lambda function, which takes about 10 seconds. The company wants the data on the leaderboard to be no more than 1 minute old.

  Which architecture will meet these requirements in the MOST operationally efficient way?

  A. Deliver the player data to an Amazon Timestream database. Create an Amazon ElastiCache for Redis cluster. Configure the Lambda function to store the results in Redis. Create a scheduled event with Amazon EventBridge to invoke the Lambda function once every minute. Reconfigure the game server to query the Redis cluster for the leaderboard data.

  B. Deliver the player data to an Amazon Timestream database. Create an Amazon DynamoDB table. Configure the Lambda function to store the results in DynamoDB. Create a scheduled event with Amazon EventBridge to invoke the Lambda function once every minute. Reconfigure the game server to query the DynamoDB table for the leaderboard data.

  C. Deliver the player data to an Amazon Aurora MySQL database. Create an Amazon DynamoDB table. Configure the Lambda function to store the results in MySQL. Create a scheduled event with Amazon EventBridge to invoke the Lambda function once every minute. Reconfigure the game server to query the DynamoDB table for the leaderboard data.

  D. Deliver the player data to an Amazon Neptune database. Create an Amazon ElastiCache for Redis cluster. Configure the Lambda function to store the results in Redis. Create a scheduled event with Amazon EventBridge to invoke the Lambda function once every minute. Reconfigure the game server to query the Redis cluster for the leaderboard data.

  Correct Answer: A

  Amazon Timestream is a serverless time series database service that allows you to store and analyze time series data at any scale1. It is well suited for gaming applications that generate high volumes of data from player events, such as scores, achievements, and actions2. Amazon ElastiCache for Redis is a fully managed in-memory data store that provides fast and scalable performance for applications that need sub-millisecond latency3. It can be used as a cache layer to store frequently accessed data, such as leaderboard results, and reduce the load on the database. AWS Lambda is a serverless compute service that lets you run code without provisioning or managing servers. It can be used to process the data from Amazon Timestream and store the leaderboard results in Amazon ElastiCache for Redis. Amazon EventBridge is a serverless event bus service that makes it easy to connect your applications with data from a variety of sources. It can be used to create a scheduled event that triggers the Lambda function once every minute, ensuring that the leaderboard data is updated regularly. The game server can then query the Redis cluster for the leaderboard data, which will be no more than 1 minute old. Option B is incorrect because Amazon DynamoDB is a key-value and document database that delivers single-digit millisecond performance at any scale. It is not designed for time series data, which requires efficient ingestion, compression, and querying of high-volume data streams. Option C is incorrect because Amazon Aurora is a relational database that combines the performance and availability of traditional enterprise databases with the simplicity and cost-effectiveness of open source databases. It is not optimized for time series data, which requires specialized indexing and partitioning techniques. Option D is incorrect because Amazon Neptune is a graph database that supports property graph and RDF models. It is not suitable for time series data, which requires high ingestion rates and temporal queries.

• Question 259:

  A company uses an Amazon Redshift cluster to run its analytical workloads. Corporate policy requires that the company's data be encrypted at rest with customer managed keys. The company's disaster recovery plan requires that backups of the cluster be copied into another AWS Region on a regular basis.

  How should a database specialist automate the process of backing up the cluster data in compliance with these policies?

  A. Copy the AWS Key Management Service (AWS KMS) customer managed key from the source Region to the destination Region. Set up an AWS Glue job in the source Region to copy the latest snapshot of the Amazon Redshift cluster from the source Region to the destination Region. Use a time-based schedule in AWS Glue to run the job on a daily basis.

  B. Create a new AWS Key Management Service (AWS KMS) customer managed key in the destination Region. Create a snapshot copy grant in the destination Region specifying the new key. In the source Region, configure cross-Region snapshots for the Amazon Redshift cluster specifying the destination Region, the snapshot copy grant, and retention periods for the snapshot.

  C. Copy the AWS Key Management Service (AWS KMS) customer-managed key from the source Region to the destination Region. Create Amazon S3 buckets in each Region using the keys from their respective Regions. Use Amazon EventBridge (Amazon CloudWatch Events) to schedule an AWS Lambda function in the source Region to copy the latest snapshot to the S3 bucket in that Region. Configure S3 Cross-Region Replication to copy the snapshots to the destination Region, specifying the source and destination KMS key IDs in the replication configuration.

  D. Use the same customer-supplied key materials to create a CMK with the same private key in the destination Region. Configure cross-Region snapshots in the source Region targeting the destination Region. Specify the corresponding CMK in the destination Region to encrypt the snapshot.

  Correct Answer: B

  According to the Amazon Redshift documentation1, you can enable database encryption for your clusters to help protect data at rest. You can use either AWS Key Management Service (AWS KMS) or a hardware security module (HSM) to

  manage the top-level encryption keys in this hierarchy. The process that Amazon Redshift uses for encryption differs depending on how you manage keys.

  To copy encrypted snapshots across Regions, you need to create a snapshot copy grant in the destination Region and specify a CMK in that Region. You also need to configure cross-Region snapshots in the source Region and provide the

  destination Region, the snapshot copy grant, and retention periods for the snapshots. This way, you can automate the process of backing up the cluster data in compliance with the corporate policies.

• Question 260:

  A single MySQL database was moved to Amazon Aurora by a business. The production data is stored in a database cluster in VPC PROD, whereas 12 testing environments are hosted in VPC TEST with the same AWS account. Testing has a negligible effect on the test data. The development team requires that each environment be updated nightly to ensure that each test database has daily production data.

  Which migration strategy will be the quickest and least expensive to implement?

  A. Run the master in Amazon Aurora MySQL. Create 12 clones in VPC_TEST, and script the clones to be deleted and re-created nightly.

  B. Run the master in Amazon Aurora MySQL. Take a nightly snapshot, and restore it into 12 databases in VPC_TEST using Aurora Serverless.

  C. Run the master in Amazon Aurora MySQL. Create 12 Aurora Replicas in VPC_TEST, and script the replicas to be deleted and re-created nightly.

  D. Run the master in Amazon Aurora MySQL using Aurora Serverless. Create 12 clones in VPC_TEST, and script the clones to be deleted and re-created nightly.

  Correct Answer: A

  https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/Aurora.Managing.Clon e.html