Amazon DBS-C01 Exam Practice Test Instant Access

Question 1

A company has deployed an e-commerce web application in a new AWS account. An Amazon RDS for MySQL Multi-AZ DB instance is part of this deployment with a database-1.xxxxxxxxxxxx.us-east- 1.rds.amazonaws.com endpoint listening on port 3306. The company's Database Specialist is able to log in to MySQL and run queries from the bastion host using these details.

When users try to utilize the application hosted in the AWS account, they are presented with a generic error message. The application servers are logging a ''could not connect to server: Connection times out'' error message to Amazon CloudWatch Logs.

What is the cause of this error?

AThe user name and password the application is using are incorrect.

BThe security group assigned to the application servers does not have the necessary rules to allow inbound connections from the DB instance.

CThe security group assigned to the DB instance does not have the necessary rules to allow inbound connections from the application servers.

DThe user name and password are correct, but the user is not authorized to use the DB instance.

Answer : C

Question 2

A company is running a blogging platform. A security audit determines that the Amazon RDS DB instance that is used by the platform is not configured to encrypt the data at rest. The company must encrypt the DB instance within 30 days.

What should a database specialist do to meet this requirement with the LEAST amount of downtime?

ACreate a read replica of the DB instance, and enable encryption. When the read replica is available, promote the read replica and update the endpoint that is used by the application. Delete the unencrypted DB instance.

BTake a snapshot of the DB instance. Make an encrypted copy of the snapshot. Restore the encrypted snapshot. When the new DB instance is available, update the endpoint that is used by the application. Delete the unencrypted DB instance.

CCreate a new encrypted DB instance. Perform an initial data load, and set up logical replication between the two DB instances When the new DB instance is in sync with the source DB instance, update the endpoint that is used by the application. Delete the unencrypted DB instance.

DConvert the DB instance to an Amazon Aurora DB cluster, and enable encryption. When the DB cluster is available, update the endpoint that is used by the application to the cluster endpoint. Delete the unencrypted DB instance.

Answer : C

https://docs.aws.amazon.com/prescriptive-guidance/latest/patterns/encrypt-an-existing-amazon-rds-for-postgresql-db-instance.html

When the new, encrypted copy of the DB instance becomes available, you can point your applications to the new database. However, if your project doesn't allow for significant downtime for this activity, you need an alternate approach that helps minimize the downtime. This pattern uses the AWS Database Migration Service (AWS DMS) to migrate and continuously replicate the data so that the cutover to the new, encrypted database can be done with minimal downtime.

Question 3

A company's database specialist implements an AWS Database Migration Service (AWS DMS) task for change data capture (CDC) to replicate data from an on- premises Oracle database to Amazon S3. When usage of the company's application increases, the database specialist notices multiple hours of latency with the CDC.

Which solutions will reduce this latency? (Choose two.)

AConfigure the DMS task to run in full large binary object (LOB) mode.

BConfigure the DMS task to run in limited large binary object (LOB) mode.

CCreate a Multi-AZ replication instance.

DLoad tables in parallel by creating multiple replication instances for sets of tables that participate in common transactions.

EReplicate tables in parallel by creating multiple DMS tasks for sets of tables that do not participate in common transactions.

Answer : B, E

Question 4

A company is using Amazon RDS for MySQL to redesign its business application. A Database Specialist has noticed that the Development team is restoring their MySQL database multiple times a day when Developers make mistakes in their schema updates. The Developers sometimes need to wait hours to the restores to complete.

Multiple team members are working on the project, making it difficult to find the correct restore point for each mistake.

Which approach should the Database Specialist take to reduce downtime?

ADeploy multiple read replicas and have the team members make changes to separate replica instances

BMigrate to Amazon RDS for SQL Server, take a snapshot, and restore from the snapshot

CMigrate to Amazon Aurora MySQL and enable the Aurora Backtrack feature

DEnable the Amazon RDS for MySQL Backtrack feature

Answer : C

'Amazon Aurora, a fully-managed relational database service in AWS, is now offering a backtrack feature. With Amazon Aurora with MySQL compatibility, users can backtrack, or 'rewind', a database cluster to a specific point in time, without restoring data from a backup. The backtrack process allows a point in time to be specified with one second resolution, and the rewind process typically takes minutes. This new feature facilitates developers in undoing mistakes like deleting data inappropriately or dropping the wrong table.'

Question 5

An online gaming company is planning to launch a new game with Amazon DynamoDB as its data store. The database should be designated to support the following use cases:

Update scores in real time whenever a player is playing the game. Retrieve a player's score details for a specific game session.

A Database Specialist decides to implement a DynamoDB table. Each player has a unique user_id and each

game has a unique game_id.

Which choice of keys is recommended for the DynamoDB table?

ACreate a global secondary index with game_id as the partition key

BCreate a global secondary index with user_id as the partition key

CCreate a composite primary key with game_id as the partition key and user_id as the sort key

DCreate a composite primary key with user_id as the partition key and game_id as the sort key

Answer : D

https://aws.amazon.com/blogs/database/amazon-dynamodb-gaming-use-cases-and-design-patterns/

'EA uses the user ID as the partition key and primary key (a 1:1 modeling pattern).' https://aws.amazon.com/blogs/database/choosing-the-right-dynamodb-partition-key/

'Partition key and sort key: Referred to as a composite primary key, this type of key is composed of two attributes. The first attribute is the partition key, and the second attribute is the sort key.'

Question 6

A banking company recently launched an Amazon RDS for MySQL DB instance as part of a proof-of-concept project. A database specialist has configured automated database snapshots. As a part of routine testing, the database specialist noticed one day that the automated database snapshot was not created.

Which of the following are possible reasons why the snapshot was not created? (Choose two.)

AA copy of the RDS automated snapshot for this DB instance is in progress within the same AWS Region.

BA copy of the RDS automated snapshot for this DB instance is in progress in a different AWS Region.

CThe RDS maintenance window is not configured.

DThe RDS DB instance is in the STORAGE_FULL state.

ERDS event notifications have not been enabled.

Answer : A, D

https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithAutomatedBackups.html

Question 7

A company wants to improve its ecommerce website on AWS. A database specialist decides to add Amazon ElastiCache for Redis in the implementation stack to ease the workload off the database and shorten the website response times. The database specialist must also ensure the ecommerce website is highly available within the company's AWS Region.

How should the database specialist deploy ElastiCache to meet this requirement?

ALaunch an ElastiCache for Redis cluster using the AWS CLI with the -cluster-enabled switch.

BLaunch an ElastiCache for Redis cluster and select read replicas in different Availability Zones.

CLaunch two ElastiCache for Redis clusters in two different Availability Zones. Configure Redis streams to replicate the cache from the primary cluster to another.

DLaunch an ElastiCache cluster in the primary Availability Zone and restore the cluster's snapshot to a different Availability Zone during disaster recovery.

Answer : B

https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/AutoFailover.html

You can enable Multi-AZ only on Redis (cluster mode disabled) clusters that have at least one available read replica. Clusters without read replicas do not provide high availability or fault tolerance.

Amazon AWS Certified Database - Specialty DBS-C01 Exam Practice Test