Amazon Amazon Certifications DBS-C01 Questions & Answers

• Question 11:

  The website of a manufacturing firm makes use of an Amazon Aurora PostgreSQL database cluster.

  Which settings will result in the LEAST amount of downtime for the application during failover? (Select three.)

  A. Use the provided read and write Aurora endpoints to establish a connection to the Aurora DB cluster.

  B. Create an Amazon CloudWatch alert triggering a restore in another Availability Zone when the primary Aurora DB cluster is unreachable.

  C. Edit and enable Aurora DB cluster cache management in parameter groups.

  D. Set TCP keepalive parameters to a high value.

  E. Set JDBC connection string timeout variables to a low value.

  F. Set Java DNS caching timeouts to a high value.

  Correct Answer: ACE

  https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraPostgreSQL.Be stPractices.html https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraPostgreSQL.clu ster-cache-mgmt.html https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraPostgreSQL.Be stPractices.html#AuroraPostgreSQL.BestPractices.FastFailover.TCPKeepalives

• Question 12:

  A company has an on-premises production Microsoft SQL Server with 250 GB of data in one database. A database specialist needs to migrate this on-premises SQL Server to Amazon RDS for SQL Server. The nightly native SQL Server backup file is approximately 120 GB in size. The application can be down for an extended period of time to complete the migration. Connectivity between the on-premises environment and AWS can be initiated from on-premises only.

  How can the database be migrated from on-premises to Amazon RDS with the LEAST amount of effort?

  A. Back up the SQL Server database using a native SQL Server backup. Upload the backup files to Amazon S3. Download the backup files on an Amazon EC2 instance and restore them from the EC2 instance into the new production RDS instance.

  B. Back up the SQL Server database using a native SQL Server backup. Upload the backup files to Amazon S3. Restore the backup files from the S3 bucket into the new production RDS instance.

  C. Provision and configure AWS DMS. Set up replication between the on-premises SQL Server environment to replicate the database to the new production RDS instance.

  D. Back up the SQL Server database using AWS Backup. Once the backup is complete, restore the completed backup to an Amazon EC2 instance and move it to the new production RDS instance.

  Correct Answer: B

  https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/SQLServer.Procedural.Import ing.html

• Question 13:

  A company is concerned about the cost of a large-scale, transactional application using Amazon DynamoDB that only needs to store data for 2 days before it is deleted. In looking at the tables, a Database Specialist notices that much of the data is months old, and goes back to when the application was first deployed.

  What can the Database Specialist do to reduce the overall cost?

  A. Create a new attribute in each table to track the expiration time and create an AWS Glue transformation to delete entries more than 2 days old.

  B. Create a new attribute in each table to track the expiration time and enable DynamoDB Streams on each table.

  C. Create a new attribute in each table to track the expiration time and enable time to live (TTL) on each table.

  D. Create an Amazon CloudWatch Events event to export the data to Amazon S3 daily using AWS Data Pipeline and then truncate the Amazon DynamoDB table.

  Correct Answer: C

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

• Question 14:

  A Database Specialist must create a read replica to isolate read-only queries for an Amazon RDS for MySQL DB instance. Immediately after creating the read replica, users that query it report slow response times. What could be causing these slow response times?

  A. New volumes created from snapshots load lazily in the background

  B. Long-running statements on the master

  C. Insufficient resources on the master

  D. Overload of a single replication thread by excessive writes on the master

  Correct Answer: A

  Explanation: snapshot is lazy loaded If the volume is accessed where the data is not loaded, the application accessing the volume encounters a higher latency than normal while the data gets loaded https://aws.amazon.com/about-aws/whats-new/2019/11/amazon-ebs-fast-snapshot- restore-eliminates-need-for-prewarming-data-into-volumes-created-snapshots/

• Question 15:

  A company is planning to close for several days. A Database Specialist needs to stop all applications along with the DB instances to ensure employees do not have access to the systems during this time. All databases are running on Amazon RDS for MySQL.

  The Database Specialist wrote and executed a script to stop all the DB instances. When reviewing the logs, the Database Specialist found that Amazon RDS DB instances with read replicas did not stop.

  How should the Database Specialist edit the script to fix this issue?

  A. Stop the source instances before stopping their read replicas

  B. Delete each read replica before stopping its corresponding source instance

  C. Stop the read replicas before stopping their source instances

  D. Use the AWS CLI to stop each read replica and source instance at the same time

  Correct Answer: B

  https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_StopInstance.html "The following are some limitations to stopping and starting a DB instance: You can't stop a DB instance that has a read replica, or that is a read replica." So if you cant stop a db with a read replica, you have to delete the read replica first to then stop it??? https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_MySQL.Replication.R eadReplicas.html#USER_MySQL.Replication.ReadReplicas.StartStop

• Question 16:

  A company has an Amazon Redshift cluster with database audit logging enabled. A security audit shows that raw SQL statements that run against the Redshift cluster are being logged to an Amazon S3 bucket. The security team requires that authentication logs are generated for use in an intrusion detection system (IDS), but the security team does not require SQL queries.

  What should a database specialist do to remediate this issue?

  A. Set the parameter to true in the database parameter group.

  B. Turn off the query monitoring rule in the Redshift cluster's workload management (WLM).

  C. Set the enable_user_activity_logging parameter to false in the database parameter group.

  D. Disable audit logging on the Redshift cluster.

  Correct Answer: C

• Question 17:

  A Database Specialist is creating a new Amazon Neptune DB cluster, and is attempting to load fata from Amazon S3 into the Neptune DB cluster using the Neptune bulk loader API. The Database Specialist receives the following error:

  "Unable to connect to s3 endpoint. Provided source = s3://mybucket/graphdata/ and region = us-east-1. Please verify your S3 configuration."

  Which combination of actions should the Database Specialist take to troubleshoot the problem? (Choose two.)

  A. Check that Amazon S3 has an IAM role granting read access to Neptune

  B. Check that an Amazon S3 VPC endpoint exists

  C. Check that a Neptune VPC endpoint exists

  D. Check that Amazon EC2 has an IAM role granting read access to Amazon S3

  E. Check that Neptune has an IAM role granting read access to Amazon S3

  Correct Answer: BD

  Reference: https://aws.amazon.com/premiumsupport/knowledge-center/s3-could-not- connect-endpoint-url/

• Question 18:

  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.

  Correct Answer: C

• Question 19:

  A user has a non-relational key-value database. The user is looking for a fully managed AWS service that will offload the administrative burdens of operating and scaling distributed databases. The solution must be cost- effective and able to handle unpredictable application traffic.

  What should a Database Specialist recommend for this user?

  A. Create an Amazon DynamoDB table with provisioned capacity mode

  B. Create an Amazon DocumentDB cluster

  C. Create an Amazon DynamoDB table with on-demand capacity mode

  D. Create an Amazon Aurora Serverless DB cluster

  Correct Answer: C

  Reference: https://aws.amazon.com/dynamodb/

  Key-value database -> DynamoDB Capable of dealing with unexpected application traffic - > on-demand capacity mode

  A key-value database is a type of nonrelational database that uses a simple key-value method to store data. A key-value database stores data as a collection of key-value pairs in which a key serves as a unique identifier. On-demand mode is a good option to create new tables with unknown workloads. https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.Read WriteCapacityMode.html#HowItWorks.OnDemand

• Question 20:

  A software company is conducting a security audit of its three-node Amazon Aurora MySQL DB cluster. Which finding is a security concern that needs to be addressed?

  A. The AWS account root user does not have the minimum privileges required for client applications.

  B. Encryption in transit is not configured for all Aurora native backup processes.

  C. Each Aurora DB cluster node is not in a separate private VPC with restricted access.

  D. The IAM credentials used by the application are not rotated regularly.

  Correct Answer: D

  Explanation: Rotate your IAM credentials regularly.