DBS-C01 Practice Test 41 — 15 Questions

Question 1

A company is migrating a 3 TB Oracle database to Amazon RDS for Oracle. They want to use Oracle Data Pump to export the data and then import it into RDS. What is the most efficient way to transfer the dump files to AWS?

Accepted Answer

Upload the dump files to Amazon S3 and then import them into RDS for Oracle using Oracle Data Pump.. Option C is correct because uploading the dump files to Amazon S3 and then using the Oracle Data Pump import from S3 (via UTL_FILE or direct read) is efficient and scalable. Option A is wrong because transferring over VPN/Direct Connect can be slow for large files. Option B is wrong because AWS Snowball is designed for very large data transfers (petabytes) and may be overkill for 3 TB, plus it adds logistics time. Option D is wrong because AWS DMS is a separate service for migration, not for transferring dump files.

Answer

Use AWS Snowball to physically ship the dump files to AWS.

Answer

Use AWS DMS to migrate the data directly from Oracle to RDS for Oracle.

Answer

Transfer the dump files over a VPN connection to an EC2 instance and then copy to RDS.

Question 2

A company is migrating a 10 TB Oracle database to Amazon RDS for Oracle. The migration window is limited to 24 hours. The source database is running on-premises with a 500 Mbps network connection. Which migration approach should be used?

Accepted Answer

Use AWS DMS with full load and ongoing replication. Option A is correct because AWS DMS with ongoing replication can handle large data volumes and minimize downtime by continuously replicating changes. Option B is wrong because Oracle Data Pump is a manual export/import process that requires downtime and may not complete within 24 hours if the network is slow. Option C is wrong because the source is on-premises, not an EC2 instance, so a read replica cannot be created. Option D is wrong because taking a backup and restoring to RDS requires the backup to be transferred to S3 first, which may be time-consuming.

Answer

Create an RDS read replica from the on-premises database

Answer

Take a physical backup of the source database and restore to RDS

Answer

Use Oracle Data Pump to export and import the database

Question 3

Refer to the exhibit. A company is creating an Aurora MySQL cluster using the AWS CLI. The command fails with an error. The company has a default KMS key but the command specifies a customer-managed KMS key. What is the most likely cause of the failure?

Accepted Answer

The IAM user does not have permission to use the specified KMS key. Option B is correct because the IAM role used to run the CLI command must have permission to use the specified KMS key. The error is likely due to missing KMS permissions. Option A is wrong because the --kms-key-id parameter is valid for Aurora clusters. Option C is wrong because the key exists; the issue is permissions. Option D is wrong because KMS keys can be used across regions if configured, but the error is more likely due to permissions.

Answer

The --kms-key-id parameter is not supported for aurora-mysql engine

Answer

The KMS key does not exist

Answer

The KMS key is in a different region

Question 4

A company is migrating a 500 GB database from Amazon RDS for MySQL to Amazon Aurora MySQL. The migration must be completed with minimal downtime and no data loss. The RDS instance is Multi-AZ. Which approach should be used?

Accepted Answer

Create an Aurora MySQL read replica from the RDS MySQL instance, then promote it. Option A is correct because creating an Aurora read replica from the RDS MySQL instance allows for a nearly zero-downtime promotion. Option B is wrong because a snapshot restore is offline. Option C is wrong because DMS would introduce additional complexity and potential data loss. Option D is wrong because replication from a Multi-AZ standby is not supported.

Answer

Use AWS DMS with ongoing replication from RDS to Aurora

Answer

Take a snapshot of the RDS instance and restore to Aurora

Answer

Set up native MySQL replication from the RDS Multi-AZ standby to Aurora

Question 5

A company is deploying a new application that requires a relational database with automatic failover and cross-Region disaster recovery. The application is read-heavy and expects up to 10 GB of data. Which combination of AWS services should be used?

Accepted Answer

Amazon Aurora with Multi-AZ and an Aurora global database. Aurora with Multi-AZ and cross-Region replica provides high availability and DR. Option A is incorrect because RDS Multi-AZ does not provide cross-Region DR. Option C is incorrect because S3 and Athena are not relational databases. Option D is incorrect because DynamoDB global tables are for NoSQL.

Answer

Amazon RDS for MySQL with Multi-AZ and a read replica in another Region

Answer

Amazon S3 with AWS Glue and Amazon Athena

Answer

Amazon DynamoDB with global tables

Question 6

A company is deploying a new web application on Amazon RDS for MySQL and expects read-heavy traffic. The database must be highly available. Which deployment approach meets these requirements?

Accepted Answer

Deploy a Multi-AZ instance and create read replicas.. Option C is correct because Multi-AZ provides high availability and read replicas offload read traffic. Option A is wrong because it lacks read scaling. Option B is wrong because it lacks high availability. Option D is wrong because Multi-AZ only provides high availability, not read scaling.

Answer

Deploy a Multi-AZ instance without read replicas.

Answer

Deploy a Single-AZ instance with a Multi-AZ read replica.

Answer

Deploy a Single-AZ instance and use ElastiCache for caching.

Question 7

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 8

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 9

Which TWO steps are required when migrating an on-premises Microsoft SQL Server database to Amazon RDS for SQL Server using AWS DMS with ongoing replication?

Accepted Answer

Enable MS-CDC (change data capture) on the source database.. Option B is correct because DMS requires full recovery model to capture all transactions. Option E is correct because DMS uses MS-CDC (change data capture) to capture ongoing changes. Option A is wrong because DMS does not require MS-Replication; it uses its own CDC mechanism. Option C is wrong because DMS uses a replication instance, not an EC2 instance agent. Option D is wrong because cross-VPC peering is not required; DMS can connect via VPN/Direct Connect.

Answer

Create a VPC peering connection between the on-premises network and the DMS VPC.

Answer

Install the DMS agent on the source SQL Server instance.

Answer

Configure MS-Replication on the source database.

Question 10

A company is deploying a new application that requires a highly available DynamoDB table with eventual consistency. The table will be accessed from multiple AWS Regions. What is the most appropriate deployment strategy?

Accepted Answer

Use DynamoDB global tables. Option C is correct because DynamoDB global tables provide multi-region replication with eventual consistency, meeting the requirements. Option A is wrong because DynamoDB Accelerator (DAX) is a caching layer, not a multi-region solution. Option B is wrong because DynamoDB Streams can be used for cross-region replication but require custom code; global tables are the managed solution. Option D is wrong because DynamoDB auto scaling adjusts capacity, not replication.

Answer

Use DynamoDB auto scaling to handle regional traffic

Answer

Use DynamoDB Accelerator (DAX) to cache data across regions

Answer

Use DynamoDB Streams to replicate data to another region

Question 11

Refer to the exhibit. A company is migrating an on-premises database to Amazon RDS for MySQL. During a test migration, the DMS task fails with the error shown. The source database is 500 GB and the target RDS instance has 500 GB allocated storage. What should be done to resolve this error and complete the migration?

Accepted Answer

Enable storage autoscaling on the RDS instance. Option A is correct because enabling storage autoscaling will allow the RDS instance to automatically increase storage when needed during the migration. Option B is wrong because the error is about storage, not instance class. Option C is wrong because the error is about the RDS instance, not the source. Option D is wrong because DMS tasks do not require an increase in RDS storage allocation upfront; autoscaling handles it.

Answer

Increase the DB instance class to a larger size

Answer

Increase the DMS task's allocated storage

Answer

Reduce the size of the source database

Question 12

A company is migrating an on-premises Oracle database to Amazon RDS for Oracle. They need to minimize downtime. Which TWO actions should they take?

Accepted Answer

Set up AWS DMS with change data capture (CDC) from the source. Options A and C are correct. Setting up AWS DMS with ongoing replication allows minimal downtime, and validating the schema with SCT before migration is a best practice. Option B is wrong because disabling archiving would prevent CDC. Option D is wrong because increasing storage does not affect downtime. Option E is wrong because a single-AZ deployment does not inherently reduce downtime.

Answer

Increase the allocated storage on the target RDS instance to improve performance

Answer

Deploy the target RDS instance as a Single-AZ to simplify replication

Answer

Disable Oracle archivelog mode to speed up data transfer

Question 13

A company is migrating a 500 GB SQL Server database to Amazon RDS for SQL Server. The database has a large number of stored procedures and triggers. The migration must have minimal downtime. Which approach should be used?

Accepted Answer

Use AWS Database Migration Service (AWS DMS) with full load and ongoing replication. AWS DMS with ongoing replication allows for minimal downtime. Option A is incorrect because backup/restore does not support ongoing replication. Option B is incorrect because S3 and Glue are not designed for database migration. Option C is incorrect because AWS SCT is for schema conversion, not data migration.

Answer

Use AWS Schema Conversion Tool (AWS SCT) to convert the schema and AWS DMS for data migration

Answer

Use AWS S3 to store the data and AWS Glue to transform and load into RDS

Answer

Use native SQL Server backup and restore to Amazon RDS

Question 14

A company is migrating a 1 TB SQL Server database to Amazon RDS for SQL Server using backup and restore. The database has high transaction volume. Which backup type should be used to minimize downtime?

Accepted Answer

Perform a full backup, then transaction log backups, and restore the full backup with the last log backup.. Option C is correct because a full backup followed by transaction log backups allows restoring to a point in time, minimizing data loss and downtime. Option A is wrong because only full backup requires longer downtime during restore and may lose transactions. Option B is wrong because differential backup alone is not sufficient; you need a full backup chain. Option D is wrong because transaction log backup alone cannot restore without a full backup.

Answer

Perform only transaction log backups and restore them to RDS.

Answer

Perform a differential backup and restore it to RDS.

Answer

Perform a full backup and restore it to RDS.

Question 15

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.