Amazon Amazon Certifications DBS-C01 Questions & Answers

• Question 81:

  An ecommerce company is running Amazon RDS for Microsoft SQL Server. The company is planning to perform testing in a development environment with production data. The development environment and the production environment are in separate AWS accounts. Both environments use AWS Key Management Service (AWS KMS) encrypted databases with both manual and automated snapshots. A database specialist needs to share a KMS encrypted production RDS snapshot with the development account.

  Which combination of steps should the database specialist take to meet these requirements? (Select THREE.)

  A. Create an automated snapshot. Share the snapshot from the production account to the development account.

  B. Create a manual snapshot. Share the snapshot from the production account to the development account.

  C. Share the snapshot that is encrypted by using the development account default KMS encryption key.

  D. Share the snapshot that is encrypted by using the production account custom KMS encryption key.

  E. Allow the development account to access the production account KMS encryption key.

  F. Allow the production account to access the development account KMS encryption key.

  Correct Answer: BDE

• Question 82:

  A company is using an Amazon ElastiCache for Redis cluster to host its online shopping website. Shoppers receive the following error when the website's application queries the cluster:

  

  Which solutions will resolve this memory issues with the LEAST amount of effort? (Choose three.)

  A. Reduce the TTL value for keys on the node.

  B. Choose a larger node type.

  C. Test different values in the parameter group for the maxmemory-policy parameter to find the ideal value to use.

  D. Increase the number of nodes.

  E. Monitor the EngineCPUUtilization Amazon CloudWatch metric. Create an AWS Lambda function to delete keys on nodes when a threshold is reached.

  F. Increase the TTL value for keys on the node.

  Correct Answer: ABC

  Explanation: https://aws.amazon.com/premiumsupport/knowledge-center/oom-command- not-allowed-redis/

• Question 83:

  A news portal is looking for a data store to store 120 GB of metadata about its posts and comments. The posts and comments are not frequently looked up or updated. However, occasional lookups are expected to be served with single-digit millisecond latency on average.

  What is the MOST cost-effective solution?

  A. Use Amazon DynamoDB with on-demand capacity mode. Purchase reserved capacity.

  B. Use Amazon ElastiCache for Redis for data storage. Turn off cluster mode.

  C. Use Amazon S3 Standard-Infrequent Access (S3 Standard-IA) for data storage and use Amazon Athena to query the data.

  D. Use Amazon DynamoDB with on-demand capacity mode. Switch the table class to DynamoDB Standard-Infrequent Access (DynamoDB Standard-IA).

  Correct Answer: C

  Explanation:

• Question 84:

  A gaming company is evaluating Amazon ElastiCache as a solution to manage player leaderboards. Millions of players around the world will complete in annual tournaments. The company wants to implement an architecture that is highly available. The company also wants to ensure that maintenance activities have minimal impact on the availability of the gaming platform.

  Which combination of steps should the company take to meet these requirements? (Choose two.)

  A. Deploy an ElastiCache for Redis cluster with read replicas and Multi-AZ enabled.

  B. Deploy an ElastiCache for Memcached global datastore.

  C. Deploy a single-node ElastiCache for Redis cluster with automatic backups enabled. In the event of a failure, create a new cluster and restore data from the most recent backup.

  D. Use the default maintenance window to apply any required system changes and mandatory updates as soon as they are available.

  E. Choose a preferred maintenance window at the time of lowest usage to apply any required changes and mandatory updates.

  Correct Answer: AE

  Explanation: https://aws.amazon.com/blogs/database/configuring-amazon-elasticache-for- redis-for-higher-availability/

• Question 85:

  An advertising company is developing a backend for a bidding platform. The company needs a cost-effective datastore solution that will accommodate a sudden increase in the volume of write transactions. The database also needs to make data changes available in a near real-time data stream.

  Which solution will meet these requirements?

  A. Amazon Aurora MySQL Multi-AZ DB cluster

  B. Amazon Keyspaces (for Apache Cassandra)

  C. Amazon DynamoDB table with DynamoDB auto scaling

  D. Amazon DocumentDB (with MongoDB compatibility) cluster with a replica instance in a second Availability Zone

  Correct Answer: C

• Question 86:

  A company has an AWS CloudFormation stack that defines an Amazon RDS DB instance. The company accidentally deletes the stack and loses recent data from the DB instance. A database specialist must change the CloudFormation template for the RDS resource to reduce the chance of accidental data loss from the DB instance in the future.

  Which combination of actions should the database specialist take to meet this requirement? (Choose three.)

  A. Set the DeletionProtection property to True.

  B. Set the MultiAZ property to True.

  C. Set the TerminationProtection property to True.

  D. Set the DeleteAutomatedBackups property to False.

  E. Set the DeletionPolicy attribute to No.

  F. Set the DeletionPolicy attribute to Retain.

  Correct Answer: ADF

• Question 87:

  In North America, a business launched a mobile game that swiftly expanded to 10 million daily active players. The game's backend is hosted on AWS and makes considerable use of a TTL-configured Amazon DynamoDB table.

  When an item is added or changed, its TTL is set to 600 seconds plus the current epoch time. The game logic is reliant on the purging of outdated data in order to compute rewards points properly. At times, items from the table are read that are many hours beyond their TTL expiration.

  How should a database administrator resolve this issue?

  A. Use a client library that supports the TTL functionality for DynamoDB.

  B. Include a query filter expression to ignore items with an expired TTL.

  C. Set the ConsistentRead parameter to true when querying the table.

  D. Create a local secondary index on the TTL attribute.

  Correct Answer: B

  https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/howitworks-ttl.html

• Question 88:

  A company plans to use AWS Database Migration Service (AWS DMS) to migrate its database from one Amazon EC2 instance to another EC2 instance as a full load task. The company wants the database to be inactive during the migration. The company will use a dms.t3.medium instance to perform the migration and will use the default settings for the migration.

  Which solution will MOST improve the performance of the data migration?

  A. Increase the number of tables that are loaded in parallel.

  B. Drop all indexes on the source tables.

  C. Change the processing mode from the batch optimized apply option to transactional mode.

  D. Enable Multi-AZ on the target database while the full load task is in progress.

  Correct Answer: B

  https://docs.aws.amazon.com/dms/latest/userguide/CHAP_BestPractices.html#CHAP_Bes tPractices.Performance

  For a full load task, we recommend that you drop primary key indexes, secondary indexes, referential integrity constraints, and data manipulation language (DML) triggers. Or you can delay their creation until after the full load tasks are complete. You don't need indexes during a full load task, and indexes incur maintenance overhead if they are present. Because the full load task loads groups of tables at a time, referential integrity constraints are violated. Similarly, insert, update, and delete triggers can cause errors, for example if a row insert is triggered for a previously bulk loaded table. Other types of triggers also affect performance due to added processing. https://docs.aws.amazon.com/dms/latest/userguide/CHAP_BestPractices.html

• Question 89:

  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?

  A. 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.

  B. 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.

  C. Create a backup plan using AWS Backup, specify a backup frequency of every 24 hours, and give the plan a nightly backup window.

  D. Configure DynamoDB backup and restore for an on-demand backup frequency of every 24 hours.

  Correct Answer: C

  https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/CreateBackup.html

  #:~:text=If%20you%20don%27t%20want%20to%20create%20scheduling%20scripts%20a nd%20cleanup%20jobs%2C%20you%20can%20use%20AWS%20Backup%20to%20creat e%20backup%20plans%20with%20schedules%20and%

  20retention%20policies%20for%2 0your%20DynamoDB%20tables.%20AWS%20Backup%20runs%20the%20backups%20an d%20deletes%20them%20when%20they%20expire.%20For%20more%20information%2C %20see%20the%

  20AWS%20Backup%20Developer%20Guide.

  https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/backuprestore_Ho wItWorks.html

• Question 90:

  A company is running an Amazon RDS for MySQL Multi-AZ DB instance for a business- critical workload. RDS encryption for the DB instance is disabled. A recent security audit concluded that all business-critical applications must encrypt data at rest. The company has asked its database specialist to formulate a plan to accomplish this for the DB instance.

  Which process should the database specialist recommend?

  A. Create an encrypted snapshot of the unencrypted DB instance. Copy the encrypted snapshot to Amazon S3. Restore the DB instance from the encrypted snapshot using Amazon S3.

  B. Create a new RDS for MySQL DB instance with encryption enabled. Restore the unencrypted snapshot to this DB instance.

  C. Create a snapshot of the unencrypted DB instance. Create an encrypted copy of the snapshot. Restore the DB instance from the encrypted snapshot.

  D. Temporarily shut down the unencrypted DB instance. Enable AWS KMS encryption in the AWS Management Console using an AWS managed CMK. Restart the DB instance in an encrypted state.

  Correct Answer: C

  https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Overview.Encryption.html#Ov erview.Encryption.Limitations