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

Question 1

A company is migrating a 2 TB MySQL database to Amazon Aurora MySQL. They need to minimize downtime and ensure data consistency. Which TWO actions should they take? (Choose two.)

Accepted Answer

Create an Amazon Aurora MySQL read replica from an Amazon RDS MySQL DB instance.. Option C is correct because you can create an Amazon Aurora MySQL read replica from an RDS MySQL DB instance, using native MySQL replication to continuously replicate data and allow a controlled, low-downtime cutover. Option D is correct because AWS DMS with change data capture (CDC) is a fully supported method for homogeneous MySQL-to-Aurora MySQL migration that continuously replicates ongoing changes and enables a low-downtime cutover. Option E is not a separate action: enabling binary logging and setting up replication is part of creating/operating an Aurora read replica, and as a standalone answer it overlaps with C. Option A is incorrect because mysqldump on a 2 TB database would cause significant downtime and no continuous replication. Option B is incorrect because AWS SCT is used for heterogeneous schema conversion, not MySQL-to-Aurora MySQL.

Answer

Export data using mysqldump and import into Aurora during a maintenance window.

Answer

Use AWS Schema Conversion Tool (SCT) to convert the schema to Aurora MySQL.

Answer

Enable binary logging (binlog) on the source RDS MySQL instance and set up replication to Aurora.

Question 2

A company needs to migrate a 10 TB SQL Server database from on-premises to Amazon RDS for SQL Server with minimal downtime. The database is heavily used with frequent write operations. Which migration strategy should be used?

Accepted Answer

Use AWS DMS with ongoing replication from the on-premises database to RDS until cutover.. AWS DMS with ongoing replication (change data capture) allows a full load of the 10 TB database followed by continuous replication of write operations from the on-premises SQL Server to Amazon RDS for SQL Server. This minimizes downtime by keeping the target database synchronized until the cutover window, where only a brief pause is needed to apply final changes and switch traffic.

Answer

Use native SQL Server backup and restore to Amazon S3, then restore to RDS.

Answer

Export the database to CSV files, upload to S3, and use the COPY command in RDS.

Answer

Use AWS Schema Conversion Tool (SCT) to convert the schema, then use AWS DMS for full load.

Question 3

A company is deploying Amazon RDS for MySQL in a Multi-AZ configuration for high availability. The database must be able to automatically failover to a standby in another Availability Zone. Which RDS feature enables this?

Accepted Answer

Multi-AZ deployment. Multi-AZ deployment for Amazon RDS automatically provisions and maintains a synchronous standby replica in a different Availability Zone. When a failure is detected, Amazon RDS automatically fails over to the standby, ensuring high availability without manual intervention. This is the native RDS feature designed specifically for automatic failover across AZs.

Answer

Automated backups

Answer

Enhanced Monitoring

Answer

Read Replicas

Question 4

A company is deploying a globally distributed application that requires a low-latency, highly available database with multi-region write support. The application needs to handle conflicts automatically. Which AWS database solution meets these requirements?

Accepted Answer

Amazon DynamoDB global tables. Amazon DynamoDB global tables provide a fully managed, multi-region, multi-active database solution that automatically replicates data across AWS Regions, supports low-latency reads and writes from any region, and uses conflict resolution based on 'last writer wins' (LWW) with a timestamp vector clock. This meets the requirement for a globally distributed application needing automatic conflict handling without custom code.

Answer

Amazon Aurora Global Database

Answer

Amazon ElastiCache for Redis global datastore

Answer

Amazon RDS Multi-AZ with cross-region read replicas

Question 5

A company is deploying Amazon RDS for PostgreSQL and needs to ensure that all data at rest is encrypted. Which action should be taken to enable encryption?

Accepted Answer

Specify an AWS KMS key when creating the RDS instance.. Amazon RDS for PostgreSQL supports encryption at rest using AWS Key Management Service (KMS). Encryption must be enabled at instance creation time by specifying an AWS KMS key; it cannot be enabled on an existing unencrypted instance. This ensures that the underlying storage, automated backups, read replicas, and snapshots are encrypted using the chosen KMS key.

Answer

Modify the existing RDS instance to enable encryption.

Answer

Enable encryption by default in the RDS console.

Answer

Enable encryption using S3 server-side encryption.

Question 6

A company is migrating a MySQL database to Amazon Aurora MySQL. The database has several stored procedures and triggers. During the migration, some stored procedures fail to execute. What is the most likely cause?

Accepted Answer

The stored procedures use features that are not compatible with Aurora MySQL.. Aurora MySQL is designed to be compatible with MySQL 5.6, 5.7, and 8.0, but it does not support all MySQL features. Stored procedures that rely on deprecated or non-standard MySQL features, such as certain SQL modes, storage engine-specific syntax, or unsupported functions, will fail to execute after migration. This is the most common cause of stored procedure failures during a migration to Aurora MySQL.

Answer

Aurora does not support stored procedures.

Answer

The stored procedures exceed the maximum size limit in Aurora.

Answer

The stored procedures use MyISAM tables, which are not supported by Aurora.

Question 7

A company is deploying a new Amazon RDS for MariaDB instance. The database must be accessible from a specific set of EC2 instances in a VPC. How should the company configure security to allow access?

Accepted Answer

Create a security group for the RDS instance that allows inbound traffic from the EC2 instances' security group.. The correct approach is to create a security group for the RDS instance whose inbound rules reference the EC2 instances' security group as the source. This allows any EC2 instance in that group to connect without hardcoding IP addresses, and it dynamically adapts as instances scale. Security group referencing is the AWS-recommended pattern for tiered application access.

Answer

Assign the same security group to both the RDS instance and the EC2 instances.

Answer

Attach an IAM role to the EC2 instances that grants access to the RDS database.

Answer

Configure a network ACL to allow inbound traffic from the EC2 instance IPs.

Question 8

A company is deploying a new Amazon RDS for Oracle instance and needs to ensure high availability and automatic failover. Which configuration should be used?

Accepted Answer

Multi-AZ deployment. (Multi-AZ deployment) is correct because it provisions a synchronous standby replica in a different Availability Zone, enabling automatic failover without data loss when the primary instance fails. This meets the high availability and automatic failover requirements for Amazon RDS for Oracle. Option D (Automated backups with point-in-time recovery) provides backup and recovery capabilities but does not ensure high availability or automatic failover; it is not a configuration for automatic failover.

Answer

Read Replicas in a different Region

Answer

Enhanced Monitoring

Answer

Automated backups with point-in-time recovery

Answer

Deletion protection

Question 9

A database administrator is trying to delete the RDS instance named 'prod-critical' using the AWS CLI. The IAM policy shown is attached to the user. What will happen?

Accepted Answer

The delete will fail because the Deny statement explicitly denies the action for that resource.. The IAM policy contains an explicit Deny statement for the rds:DeleteDBInstance action on the resource arn:aws:rds:us-east-1:123456789012:db:prod-critical. In AWS IAM, an explicit Deny always overrides any Allow, so the delete operation will be denied. Therefore, the CLI command will fail with an AccessDenied error.

Answer

The delete will succeed only if the user includes a condition.

Answer

The delete will fail because the policy has a syntax error.

Answer

The delete will succeed because the Allow statement grants permission.

Question 10

A developer deploys the CloudFormation stack. After testing, they delete the stack. What happens to the RDS instance?

Accepted Answer

The RDS instance is deleted without a final snapshot.. By default, when a CloudFormation stack containing an RDS DB instance is deleted, the instance is deleted without a final snapshot. CloudFormation's default DeletionPolicy is Delete; a final snapshot is only taken if DeletionPolicy is explicitly set to Snapshot. The stem does not mention any custom DeletionPolicy, so the default behavior applies. Option C correctly describes this outcome.

Answer

The RDS instance is retained and the stack deletion fails.

Answer

The RDS instance is deleted after a final snapshot is taken.

Answer

The RDS instance is retained and a final snapshot is taken automatically.

Question 11

A developer is connecting to an RDS for MySQL instance. What is the endpoint address that should be used in the database connection string?

Accepted Answer

mydb.123456789012.us-east-1.rds.amazonaws.com. When connecting to an Amazon RDS for MySQL instance, the endpoint is a fully qualified domain name (FQDN) that resolves to the underlying database host. Option B provides the correct FQDN format: a DB instance identifier followed by a randomly generated alphanumeric string, the AWS region, and the rds.amazonaws.com domain. This endpoint is found in the RDS console under the instance's 'Connectivity & security' tab and is required by MySQL clients to establish a TCP connection.

Answer

mydb

Answer

3306

Answer

Z1R2S3V4X5Y6Z7

Question 12

A company wants to migrate an on-premises Oracle database to Amazon RDS for Oracle with minimal downtime. Which AWS service should be used for the initial data load and ongoing replication?

Accepted Answer

AWS Database Migration Service (DMS). AWS Database Migration Service (DMS) is the correct choice because it supports both full-load migration and ongoing change data capture (CDC) replication from Oracle to Amazon RDS for Oracle. DMS uses Oracle LogMiner or binary reader to capture incremental changes from the source database's redo logs, enabling near-zero downtime migration without requiring application modifications.

Answer

AWS Snowball

Answer

AWS Direct Connect

Answer

AWS Schema Conversion Tool (SCT)

Question 13

A company wants to migrate an on-premises SQL Server database to Amazon RDS for SQL Server. They need to convert stored procedures and functions. Which AWS service should they use?

Accepted Answer

AWS SCT. AWS SCT (Schema Conversion Tool) is the correct service because it specializes in converting database schemas, including stored procedures and functions, from one engine to another. For migrating on-premises SQL Server to Amazon RDS for SQL Server, SCT can analyze and convert the schema objects, handling syntax differences and compatibility issues automatically.

Answer

AWS CloudEndure Migration

Answer

AWS DMS

Answer

AWS Snowball

Question 14

A company is deploying a new web application that uses Amazon RDS for MySQL. To improve read performance, they add a read replica. However, the application reports stale data. What is the most likely cause?

Accepted Answer

The replication is asynchronous and there is replication lag.. Amazon RDS for MySQL uses asynchronous replication for read replicas. The primary instance commits writes and then sends the binary log (binlog) events to the replica, which applies them. This asynchronous nature introduces replication lag, meaning the replica may not have the most recent writes. If the application reads from the replica before the lag is resolved, it will see stale (older) data.

Answer

The application is using a connection pool that caches connections to the primary.

Answer

The read replica is in a different AWS Region.

Answer

The application is reading from the replica before the write is committed on the primary.

Question 15

A company is planning to deploy an Amazon RDS for PostgreSQL instance. Which of the following is a required step to enable automated backups?

Accepted Answer

Set the backup retention period to a value greater than 0.. Automated backups in Amazon RDS for PostgreSQL are enabled by setting a backup retention period greater than 0 days. By default, the retention period is 0, which disables automated backups. Once set to a value between 1 and 35 days, RDS automatically takes daily snapshots and retains transaction logs for point-in-time recovery within that window.

Answer

Set a preferred maintenance window.

Answer

Enable encryption at rest.

Answer

Configure a Multi-AZ deployment.