AWS Certified Database - Specialty

Here you have the best Amazon DBS-C01 practice exam questions

You have 359 total questions to study from
Each page has 5 questions, making a total of 72 pages
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This questions were last updated on May 4, 2025

Question 1 of 359

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?

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

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

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

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

Correct Answer: C

The error message 'could not connect to server: Connection times out' commonly indicates an issue with network connectivity or firewalls. In the context of AWS, security groups act as virtual firewalls to control inbound and outbound traffic to instances. Since the application servers cannot connect to the database, it is likely that the security group associated with the DB instance does not have a rule allowing inbound connections on the MySQL default port (3306) from the application servers. Ensuring the correct security group rules are in place would resolve this connectivity issue.

Question 2 of 359

An AWS CloudFormation stack that included an Amazon RDS DB instance was accidentally deleted and recent data was lost. A Database Specialist needs to add

RDS settings to the CloudFormation template to reduce the chance of accidental instance data loss in the future.

Which settings will meet this requirement? (Choose three.)

Set DeletionProtection to True

Set MultiAZ to True

Set TerminationProtection to True

Set DeleteAutomatedBackups to False

Set DeletionPolicy to Delete

Set DeletionPolicy to Retain

Correct Answer: A, D, F

ACF

Reference:

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-attribute-deletionpolicy.html

https://aws.amazon.com/premiumsupport/knowledge-center/cloudformation-accidental-updates/

Question 3 of 359

A Database Specialist is troubleshooting an application connection failure on an Amazon Aurora DB cluster with multiple Aurora Replicas that had been running with no issues for the past 2 months. The connection failure lasted for 5 minutes and corrected itself after that. The Database Specialist reviewed the Amazon

RDS events and determined a failover event occurred at that time. The failover process took around 15 seconds to complete.

What is the MOST likely cause of the 5-minute connection outage?

After a database crash, Aurora needed to replay the redo log from the last database checkpoint

The client-side application is caching the DNS data and its TTL is set too high

After failover, the Aurora DB cluster needs time to warm up before accepting client connections

There were no active Aurora Replicas in the Aurora DB cluster

Correct Answer: B

The 5-minute connection outage is most likely caused by the client-side application caching the DNS data with a time-to-live (TTL) set too high. After a failover, the underlying IP address of a DB instance can change. If the application continues to use a cached DNS entry with the old IP address, it will fail to connect to the new instance. Setting a shorter TTL for the DNS cache would ensure that the client application updates its DNS information quickly after a failover.

Question 4 of 359

A company is deploying a solution in Amazon Aurora by migrating from an on-premises system. The IT department has established an AWS Direct Connect link from the company's data center. The company's Database Specialist has selected the option to require SSL/TLS for connectivity to prevent plaintext data from being set over the network. The migration appears to be working successfully, and the data can be queried from a desktop machine.

Two Data Analysts have been asked to query and validate the data in the new Aurora DB cluster. Both Analysts are unable to connect to Aurora. Their user names and passwords have been verified as valid and the Database Specialist can connect to the DB cluster using their accounts. The Database Specialist also verified that the security group configuration allows network from all corporate IP addresses.

What should the Database Specialist do to correct the Data Analysts' inability to connect?

Restart the DB cluster to apply the SSL change.

Instruct the Data Analysts to download the root certificate and use the SSL certificate on the connection string to connect.

Add explicit mappings between the Data Analysts' IP addresses and the instance in the security group assigned to the DB cluster.

Modify the Data Analysts' local client firewall to allow network traffic to AWS.

Correct Answer: B

The Data Analysts are unable to connect to the Aurora DB cluster likely because the connection requires SSL/TLS and they have not configured their connections to use the SSL certificate. To connect using SSL/TLS, the Analysts need to download the root certificate provided by AWS and include it in their connection string. This ensures that the connection is secure, as required by the Database Specialist's settings. Restarting the DB cluster, modifying firewalls, or adding IP address mappings wouldn't address this SSL requirement directly.

Question 5 of 359

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?

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.

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

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

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

To reduce the overall cost, the Database Specialist should create a new attribute in each table to track the expiration time and enable time to live (TTL) on each table. TTL automatically deletes expired items from the table without requiring manual intervention, effectively managing storage costs by ensuring that only necessary data is retained. Unlike complex solutions involving AWS Glue transformations or data pipelines, TTL is a native feature of DynamoDB designed specifically for this purpose and does not incur additional costs.