DBS-C01 Deployment and Migration Practice Test 20 — 15 Questions

Question 1

Refer to the exhibit. A developer runs the command against an RDS MySQL instance. The application team reports that the database is experiencing high read latency during peak hours. The database is not currently in Multi-AZ. What is the MOST cost-effective way to reduce read latency?

Accepted Answer

Create a read replica in the same region.. Option C is correct because creating a read replica offloads read traffic from the primary instance, reducing read latency without changing the instance class. Option A is wrong because enabling Multi-AZ is for high availability, not read performance. Option B is wrong because upgrading to a larger instance class is more expensive than adding a read replica. Option D is wrong because converting to Aurora is a significant migration effort and may not be cost-effective for this issue.

Answer

Enable Multi-AZ to distribute reads to the standby.

Answer

Upgrade the instance to db.r5.2xlarge.

Answer

Migrate to Aurora MySQL with a read replica.

Question 2

Refer to the exhibit. A developer deploys this CloudFormation template. An application on the EC2 instance cannot connect to the RDS MySQL database. What is the MOST likely cause?

Accepted Answer

The EC2 security group allows inbound MySQL from 0.0.0.0/0 but the RDS security group only allows traffic from the VPC CIDR, which does not include the EC2 security group.. Option A is correct because the RDS security group (MyDBSecurityGroup) only allows inbound traffic from the VPC CIDR (10.0.0.0/16), but the EC2 security group (MyEC2SecurityGroup) does not allow traffic from the RDS security group. Additionally, the EC2 instance is in the same VPC but the security group rules do not reference the EC2 security group. Option B is wrong because the subnets are in the same VPC and there is no mention of different AZs being an issue. Option C is wrong because there is no encryption configured. Option D is wrong because DeletionProtection does not affect connectivity.

Answer

The RDS instance has encryption enabled, preventing access from EC2.

Answer

The RDS instance has DeletionProtection enabled, which blocks connections.

Answer

The EC2 instance is in a different Availability Zone than the RDS instance.

Question 3

A company is migrating a 500 GB on-premises Oracle database to Amazon RDS for Oracle. The migration must have minimal downtime. Which AWS service should be used for the initial data load and ongoing replication?

Accepted Answer

AWS Database Migration Service (AWS DMS). AWS Database Migration Service (DMS) supports both full load and ongoing replication from Oracle to RDS Oracle, enabling minimal downtime migrations. Option A (S3) does not provide replication. Option B (Snowball) is offline. Option D (DataSync) is for file data, not databases.

Answer

AWS Snowball Edge for offline data transfer

Answer

Amazon S3 to store backup files and restore

Answer

AWS DataSync

Question 4

A company is moving a self-hosted MySQL database to Amazon Aurora MySQL. The current database uses InnoDB with full-text indexes and triggers. The migration must be done with zero downtime. Which approach meets these requirements?

Accepted Answer

Use AWS DMS with ongoing replication from the source MySQL database. AWS DMS can migrate MySQL to Aurora MySQL with ongoing replication (CDC), supporting InnoDB tables, full-text indexes, and triggers. Option A fails because mysqldump causes downtime. Option B fails because Aurora does not support replication from external MySQL. Option D is incorrect because S3 bucket loading is not supported for MySQL.

Answer

Use mysqldump to export the database and import into Aurora

Answer

Set up MySQL replication from on-premises to Aurora using native binlog replication

Answer

Export data to Amazon S3 and use Aurora's LOAD DATA FROM S3 command

Question 5

A company wants to migrate a 10 TB Microsoft SQL Server database from on-premises to Amazon RDS for SQL Server. The migration must be completed within a week and minimize network bandwidth usage. Which approach is most suitable?

Accepted Answer

Use AWS Snowball Edge to transfer backup files, then restore to RDS. AWS Snowball Edge is the most suitable approach because it allows you to transfer the 10 TB database backup files physically, bypassing the internet entirely. This eliminates network bandwidth constraints and ensures the migration can be completed within a week, as the data is shipped to AWS and then restored to Amazon RDS for SQL Server using native restore operations.

Answer

Back up the database to Amazon S3 using AWS CLI

Answer

Set up AWS Direct Connect and use DMS

Answer

Use AWS DMS over the internet

Question 6

A company is deploying a new multi-AZ Amazon RDS for PostgreSQL database. The security team requires that all traffic to the database be encrypted in transit. Which configuration ensures this?

Accepted Answer

Enable SSL/TLS and require client connections to use SSL. Enabling SSL/TLS and enforcing that client connections use SSL ensures encryption in transit. Option A (encryption at rest) does not cover transit. Option B (default VPC) does not enforce encryption. Option D (KMS) is for encryption at rest.

Answer

Use a customer master key (CMK) for RDS

Answer

Place the RDS instance in a public subnet

Answer

Enable encryption at rest using AWS KMS

Question 7

A company is deploying a MongoDB-compatible database using Amazon DocumentDB. The application requires the ability to perform ad-hoc queries on nested fields within documents. Which DocumentDB feature should be enabled to meet this requirement?

Accepted Answer

Indexes on nested fields. Amazon DocumentDB supports indexing on nested fields, which allows efficient querying of sub-documents and arrays within documents. By creating indexes on specific nested paths (e.g., "address.city"), the query engine can perform index scans instead of full collection scans, enabling fast ad-hoc queries on nested fields. This feature directly meets the requirement for ad-hoc queries on nested fields.

Answer

TTL indexes

Answer

Transactions

Answer

Change streams

Question 8

A company needs to migrate a 2 TB PostgreSQL database from an on-premises data center to Amazon Aurora PostgreSQL. The network bandwidth is limited to 100 Mbps. The migration window is 5 days. Which approach is most cost-effective and likely to succeed?

Accepted Answer

Use AWS DMS with a VPN connection to the on-premises database. Using AWS DMS over a VPN connection allows online migration without physical devices. Snowball requires shipping time. Direct Connect has setup time and cost. S3 import is not supported for Aurora PostgreSQL.

Answer

Set up AWS Direct Connect and use DMS

Answer

Use AWS Snowball Edge to transfer data offline

Answer

Export to Amazon S3 and import into Aurora

Question 9

A company is deploying an Amazon RDS for MySQL database in a VPC. The database must be accessible only from a specific set of application servers in the same VPC. Which configuration provides the most secure access?

Accepted Answer

Set the security group inbound rule to reference the security group of the application servers. Using a security group that references the application servers' security group is the most secure because it allows traffic based on security group ID, not IP. Option A (publicly accessible) is insecure. Option B (all traffic from VPC CIDR) is too broad. Option D (database subnet group) does not control ingress traffic.

Answer

Set the security group inbound rule to allow all traffic from the VPC CIDR

Answer

Place the RDS instance in a separate subnet group

Answer

Set the RDS instance to publicly accessible

Question 10

A company is migrating a 1 TB Oracle database to Amazon RDS for Oracle. The source database has a high volume of small transactions. The migration must minimize source database impact. Which AWS DMS configuration should be used?

Accepted Answer

Use full load only and disable ongoing replication. Using a full load without CDC for the initial migration minimizes impact because CDC adds overhead. Batch-optimized applies changes in batches, but CDC still runs. Using multiple tasks increases overhead. Full load only is the least impactful.

Answer

Use batch-optimized apply mode

Answer

Use full load with CDC (ongoing replication)

Answer

Use multiple DMS tasks to parallelize the migration

Question 11

A company is deploying Amazon DynamoDB for a new application. The application requires single-digit millisecond latency for read operations. Which DynamoDB feature should be configured to meet this requirement?

Accepted Answer

DynamoDB Accelerator (DAX). DynamoDB Accelerator (DAX) is a fully managed, highly available, in-memory cache that delivers up to 10x read performance improvement. Option B (Auto Scaling) handles throughput. Option C (TTL) expires items. Option D (Streams) captures changes.

Answer

DynamoDB Streams

Answer

Auto Scaling

Answer

Time to Live (TTL)

Question 12

Which TWO options are valid methods to migrate an on-premises Microsoft SQL Server database to Amazon RDS for SQL Server with minimal downtime? (Choose 2.)

Accepted Answer

Use AWS DMS with ongoing replication. AWS DMS supports both full load and ongoing replication from SQL Server to RDS. Native backup/restore to S3 is also supported. Option C (ssis) is for ETL, not migration. Option D (Direct Connect) is a network service, not a migration method. Option E (Snowball) is offline.

Answer

Use AWS Snowball Edge

Answer

Use SQL Server Integration Services (SSIS)

Answer

Use AWS Direct Connect

Question 13

Which THREE considerations are important when deploying Amazon Aurora Global Database? (Choose 3.)

Accepted Answer

Each secondary region can have up to 16 read replicas. Aurora Global Database supports up to 5 secondary regions, uses storage-based replication, and allows failover to a secondary region. Option C (cross-region read replicas) is not used; instead Global Database uses dedicated clusters. Option D (DMS) is not required. Option E (S3) is not used.

Answer

AWS DMS must be used to set up replication

Answer

Cross-region read replicas are created for each secondary region

Answer

Amazon S3 is used to store transaction logs

Question 14

Which TWO AWS services can be used to migrate a MongoDB database to Amazon DocumentDB? (Choose 2.)

Accepted Answer

AWS Database Migration Service (AWS DMS). AWS DMS supports migration from MongoDB to DocumentDB, and MongoDB's native mongodump and mongorestore can be used. Option C (S3) is not directly used. Option D (DataSync) is for file data. Option E (Kinesis) is for streaming data.

Answer

AWS DataSync

Answer

Amazon S3

Answer

Amazon Kinesis Data Streams

Question 15

An IAM policy is attached to a user who is deploying an RDS database. The user attempts to create a DB instance named 'my-database' using the AWS CLI. Which statement is true?

Accepted Answer

The user can create the DB instance. The policy allows rds:CreateDBInstance on the specific DB instance and allows rds:CreateDBSubnetGroup on all resources. There is a Deny on ModifyDBInstance, but that action is not performed. The user can create the DB instance. Option A is incorrect because the Deny does not prevent creation. Option C is incorrect because the policy allows creation. Option D is incorrect because the policy is valid.

Answer

The user cannot create the DB instance because the Deny statement applies to all actions

Answer

The user cannot create the DB instance because the resource ARN does not exist yet

Answer

The user cannot create the DB instance because of an error in the policy