DBS-C01 Deployment and Migration Practice Test 5 — 15 Questions

Question 1

A company is migrating a self-hosted MongoDB replica set to Amazon DocumentDB. The source MongoDB is version 4.0, and the target DocumentDB is 3.6. The migration must be online with minimal downtime. Which approach should be taken?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Use AWS DMS with ongoing replication from MongoDB to DocumentDB.. AWS DMS supports ongoing replication (change data capture) from MongoDB to Amazon DocumentDB. It can capture changes from the MongoDB oplog and apply them to DocumentDB in near real-time, enabling an online migration with minimal downtime. Option B is incorrect because using a custom application to capture oplog changes is unnecessary and more complex, as DMS provides built-in CDC functionality for this migration path.

Answer

Use a custom application to capture MongoDB oplog changes and apply to DocumentDB.

Answer

Configure DocumentDB as a replica of the MongoDB primary.

Answer

Export MongoDB collection data to JSON files, then import into DocumentDB.

Question 2

A company is deploying a new web application that requires a highly available MariaDB database. The application is read-heavy and needs to scale read traffic. Which deployment approach meets these requirements?

Accepted Answer

Deploy a Multi-AZ RDS for MariaDB with one or more read replicas.. Deploying a Multi-AZ RDS for MariaDB provides high availability through automatic failover to a standby in a different Availability Zone, while adding one or more read replicas offloads read traffic from the primary instance, meeting the read-heavy scaling requirement. This combination ensures both fault tolerance and read scalability for a MariaDB database.

Answer

Deploy Amazon Aurora MySQL with a read replica.

Answer

Deploy a Multi-AZ RDS for MariaDB instance.

Answer

Deploy a single-AZ RDS for MariaDB with a read replica.

Question 3

A company is migrating a self-managed PostgreSQL database with extensions (PostGIS, pg_stat_statements) to Amazon RDS for PostgreSQL. After migration, they find that the extensions are not available. What is the most likely cause?

Accepted Answer

The required extensions are not included in the default parameter group and must be manually added to shared_preload_libraries.. Amazon RDS for PostgreSQL does not automatically load extensions that require shared library preloading, such as pg_stat_statements. These extensions must be explicitly added to the `shared_preload_libraries` parameter in the DB parameter group. PostGIS, while not requiring preloading, must be created via `CREATE EXTENSION` after the extension files are present; however, the most likely cause of extensions not being available is that the custom parameter group was not configured to include the required libraries in `shared_preload_libraries`.

Answer

The extensions are incompatible with the RDS engine version.

Answer

The RDS instance is not configured to allow extensions.

Answer

RDS does not support any PostgreSQL extensions.

Question 4

A company is migrating a 1 TB on-premises SQL Server database to Amazon RDS for SQL Server. The migration must be completed within 24 hours and with minimal downtime. Which TWO approaches should be used? (Choose 2)

Accepted Answer

Use AWS DMS with ongoing replication (CDC).. Option C is correct because AWS DMS with ongoing replication (Change Data Capture) performs a full load and then continuously replicates ongoing changes from the source SQL Server to RDS, keeping the target in sync and enabling a cutover with minimal downtime within the 24-hour window. Option D is correct because AWS Schema Conversion Tool (AWS SCT) assesses and converts the source schema and objects to be compatible with the RDS for SQL Server target, which is a necessary step when migrating a database to ensure objects, data types, and code are compatible before or alongside the DMS data migration. Option A is not appropriate because AWS DMS does not use SSIS packages for migration; SSIS is a separate SQL Server ETL tool and is not the mechanism DMS relies on. Option B is not the best fit because native backup and restore to S3 typically requires taking the database offline or incurring downtime during the backup/restore process, which conflicts with the minimal-downtime requirement. Option E is incorrect because a DMS full load only migrates existing data without capturing ongoing changes, resulting in downtime during the final cutover and risking data loss for changes made during the migration.

Answer

Use AWS DMS with SSIS packages.

Answer

Use native backup and restore to S3.

Answer

Use AWS DMS full load only.

Question 5

A company is deploying a new MySQL database on Amazon RDS. They need to ensure that the database is automatically backed up daily and retained for 30 days. Which TWO configurations should be set? (Choose 2)

Accepted Answer

Set backup retention period to 30 days.. Setting the backup retention period to 30 days ensures that automated backups are retained for the required duration. Option B is correct because automated backups must be enabled for the retention period to take effect; without enabling automated backups, no automatic daily backups occur. Together, these two settings satisfy the requirement for daily automated backups retained for 30 days.

Answer

Set backup window.

Answer

Enable Multi-AZ deployment.

Answer

Create a manual snapshot daily.

Question 6

Refer to the exhibit. An IAM policy is attached to a user who needs to deploy an RDS MySQL instance. After creating the instance, the user tries to modify it to enable deletion protection, but the action fails. What is the most likely reason?

Accepted Answer

The user does not have permission to enable deletion protection.. The IAM policy shown in the exhibit grants `rds:CreateDBInstance` but does not include `rds:ModifyDBInstance` or the specific action required to enable deletion protection (`rds:ModifyDBInstance` with the `DeletionProtection` parameter). Enabling deletion protection is a modification action, not part of the creation process, so the user lacks the necessary IAM permission for that operation.

Answer

The user does not have permission to describe instances.

Answer

The resource ARN is not specified in the policy.

Answer

The user does not have permission to create the instance.

Question 7

A company is migrating a 3 TB on-premises Oracle database to Amazon Aurora PostgreSQL. The source database runs Oracle 12c on a Linux server with a 1 Gbps network connection to AWS via Direct Connect. The migration must have minimal downtime and be completed within a 2-day window. The database is heavily used during business hours (9 AM - 5 PM) and has low activity overnight. The company has a test environment on AWS already. The migration team plans to use AWS DMS with CDC for ongoing replication. They also plan to use AWS SCT for schema conversion. They start the migration on a Friday evening. On Saturday morning, the CDC replication lag is increasing, and the target Aurora instance is struggling to keep up. The team notices that the source database has a high number of write transactions even during the weekend, and the DMS replication instance is a small instance type. Which action should the team take to complete the migration on time?

Accepted Answer

Upgrade the DMS replication instance to a larger size to increase throughput.. The CDC replication lag is increasing because the DMS replication instance is too small to handle the high write volume. Upgrading to a larger instance type increases CPU, memory, and network throughput, allowing DMS to process changes faster and catch up. Other options like reducing tables or pausing would not meet the deadline, and Snowball is for one-time transfers, not ongoing replication.

Answer

Reduce the number of tables being migrated to lower the load.

Answer

Pause the migration and restart it on Monday during low activity.

Answer

Switch to use AWS Snowball to transfer data and bypass DMS.

Question 8

A company is deploying a new web application that uses Amazon RDS for MySQL. The application has unpredictable read traffic spikes. The company wants to minimize read latency and automatically scale read capacity. What is the MOST cost-effective solution?

Accepted Answer

Create an Amazon RDS read replica and configure the application to use it for read traffic. Amazon RDS read replicas allow you to offload read traffic from the primary DB instance to one or more replicas, which can be scaled horizontally by adding more replicas as needed. This is the most cost-effective solution among the options for handling unpredictable read spikes because it directly addresses read capacity scaling without the cost of a full caching layer. Multi-AZ provides only high availability, not read scaling; ElastiCache adds cost and complexity; RDS Proxy manages connections but does not scale read capacity.

Answer

Use Amazon ElastiCache as a caching layer

Answer

Use Amazon RDS Proxy to manage connections

Answer

Deploy the RDS instance in a Multi-AZ configuration

Question 9

A company wants to migrate a 10 GB PostgreSQL database from an on-premises server to Amazon RDS for PostgreSQL. The migration can tolerate several hours of downtime. Which migration method is the MOST straightforward?

Accepted Answer

Use pg_dump to export the database and pg_restore to import into RDS. Pg_dump and pg_restore are native PostgreSQL utilities that provide a straightforward, reliable method for migrating a 10 GB database with acceptable downtime. The 10 GB size is well within the practical limits of a logical dump, and the process requires no additional AWS services or complex configuration, making it the simplest approach for a migration that can tolerate several hours of downtime.

Answer

Use AWS Database Migration Service (AWS DMS) with ongoing replication

Answer

Use AWS Schema Conversion Tool (AWS SCT) to migrate the data

Answer

Create an Amazon RDS Read Replica from the on-premises database

Question 10

A company is deploying a new Amazon Aurora MySQL database. The development team requires a separate database instance for testing that is a clone of the production database but does not require the same level of performance. What is the MOST cost-effective way to create this test database?

Accepted Answer

Use the Aurora cloning feature to create a clone of the production cluster. The Aurora cloning feature creates a copy of the production cluster that is both fast and storage-efficient, using copy-on-write technology. This clone can be created with a different (smaller) DB instance class than the source, meeting the requirement for lower performance at minimal cost, as no additional storage is provisioned until data is modified.

Answer

Create a new Aurora cluster from the latest snapshot of the production cluster

Answer

Create a read replica of the production cluster and promote it to a standalone cluster

Answer

Create a new Aurora cluster and use a smaller DB instance class

Question 11

A company is migrating a 5 TB SQL Server database to Amazon RDS for SQL Server. The migration must be completed within 48 hours with minimal downtime. The network bandwidth between on-premises and AWS is 500 Mbps. What is the MOST efficient migration strategy?

Accepted Answer

Use AWS Snowball to transfer the full database to an RDS instance, then use AWS DMS for ongoing replication. A 5 TB database over 500 Mbps would take approximately 23 hours for the initial full load alone (5 TB * 8 / 500 Mbps = 80,000 seconds ≈ 22.2 hours), leaving insufficient time for ongoing replication within the 48-hour window. AWS Snowball provides a physical transfer of the full database, bypassing network constraints, and then AWS DMS can perform ongoing change data capture (CDC) replication to apply incremental changes with minimal downtime.

Answer

Upgrade network bandwidth to 10 Gbps using AWS Direct Connect

Answer

Use AWS Database Migration Service (AWS DMS) with ongoing replication

Answer

Use AWS Schema Conversion Tool (AWS SCT) to migrate the schema, then use bulk insert

Question 12

Refer to the exhibit. A database administrator is trying to use AWS DMS to migrate data from an on-premises Oracle database to Amazon RDS for Oracle. The DMS replication instance is in the same VPC as the RDS instance. The administrator receives an access denied error when starting the replication task. The IAM policy attached to the DMS replication instance is shown. What is the MOST likely cause of the error?

Accepted Answer

The IAM policy does not include permissions for the source database endpoint. The error occurs because the IAM policy attached to the DMS replication instance does not include the necessary permissions to access the source Oracle database endpoint. Specifically, the policy lacks actions like `dms:TestConnection` and `dms:DescribeEndpoints` that are required for DMS to validate and connect to the source endpoint. Without these permissions, DMS cannot establish the connection to the on-premises Oracle database, resulting in an access denied error when starting the replication task.

Answer

The IAM policy does not allow the dms:CreateReplicationInstance action

Answer

The RDS instance is not in the same VPC as the DMS replication instance

Answer

The DMS replication instance is not associated with the IAM role

Question 13

A company wants to migrate an on-premises MongoDB database to Amazon DocumentDB. The migration should be performed with minimal application changes. Which AWS service should be used?

Accepted Answer

AWS Database Migration Service (AWS DMS). AWS DMS is the correct service because it supports homogeneous migrations from MongoDB to Amazon DocumentDB, including ongoing replication via change data capture (CDC) to minimize downtime. It handles schema conversion automatically for compatible data types, requiring minimal application changes since DocumentDB is MongoDB-compatible. AWS DMS can migrate data directly from a MongoDB source to a DocumentDB target without needing an intermediate schema transformation tool.

Answer

Amazon S3 Transfer Acceleration

Answer

AWS DataSync

Answer

AWS Schema Conversion Tool (AWS SCT)

Question 14

A company is migrating a 1 TB SQL Server database to Amazon RDS for SQL Server. The migration requires minimal downtime and must support ongoing changes. Which TWO AWS services should be used together to achieve this? (Choose two.)

Accepted Answer

AWS Database Migration Service (AWS DMS) and AWS Schema Conversion Tool (AWS SCT). To migrate a 1 TB SQL Server database to Amazon RDS for SQL Server with minimal downtime and ongoing changes, two services are needed. AWS DMS provides continuous replication (change data capture) to keep the target synchronized. For the initial bulk transfer of 1 TB, AWS Snowball can physically move the data offline, reducing network load and accelerating the initial load; DMS then takes over for ongoing changes. Alternatively, DMS can be combined with AWS SCT for schema conversion and optimization, which is useful even when migrating to the same engine. Thus, both options D (DMS+SCT) and E (DMS+Snowball) are correct because they represent valid combinations for achieving minimal-downtime migration with ongoing changes.

Answer

AWS Schema Conversion Tool (AWS SCT) and AWS Snowball

Answer

AWS Database Migration Service (AWS DMS) and AWS Direct Connect

Answer

AWS Database Migration Service (AWS DMS) and AWS Lambda

Question 15

A company is planning to deploy a new Amazon RDS for Oracle database in a Multi-AZ configuration. The database must be highly available and fault-tolerant. Which THREE actions should the company take to meet these requirements? (Choose three.)

Accepted Answer

Enable Multi-AZ deployment. Enabling Multi-AZ deployment for Amazon RDS for Oracle automatically provisions and maintains a synchronous standby replica in a different Availability Zone. This provides automatic failover in the event of an AZ outage or primary instance failure, ensuring high availability and fault tolerance without manual intervention.

Answer

Take manual snapshots daily

Answer

Create a read replica in a different Availability Zone