DBS-C01 Deployment and Migration Practice Test 11 — 15 Questions

Question 1

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. Option D is correct because 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 2

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. Aurora cloning creates a logical copy of the cluster volume that is space-efficient and fast, using copy-on-write semantics. Creating a new instance from a snapshot incurs storage costs and takes longer. Read replicas are for read scaling, not cloning. Using a different DB instance class does not reduce storage.

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 3

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. Given the bandwidth and time constraints, using AWS DMS with ongoing replication is the best approach for minimal downtime. However, the initial load may be slow. Using Snowball to transfer the full database and then using DMS for ongoing replication is more efficient, as it avoids the initial load over the network. Direct Connect doesn't solve bandwidth limitation. SCT is for schema conversion.

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 4

A company is deploying a new application that uses Amazon RDS for PostgreSQL. The application must be highly available with automatic failover in the event of a database failure. Which configuration should be used?

Accepted Answer

Deploy a Multi-AZ RDS instance with a standby in a different Availability Zone. Multi-AZ deployment with a standby instance in a different Availability Zone provides automatic failover. Read replicas are for read scaling, not failover. Single-AZ has no automatic failover. Cross-Region replication is for disaster recovery, not automatic failover.

Answer

Use a read replica in a different Availability Zone

Answer

Deploy the RDS instance in a single Availability Zone with automated backups

Answer

Deploy the RDS instance in a Cross-Region replication configuration

Question 5

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 IAM policy allows dms:CreateReplicationTask and dms:StartReplicationTask on replication tasks, and rds:DescribeDBInstances. However, DMS needs permissions to describe RDS instances (rds:DescribeDBInstances is allowed) and to access the source endpoint (on-premises). But the error is likely due to missing permissions on the source endpoint or network connectivity. However, the most common issue is that the DMS replication instance needs permissions to access the source database, but the policy only allows actions on replication tasks, not on endpoints. DMS also needs dms:CreateEndpoint and dms:TestConnection. However, the policy shown is too restrictive. The question asks for the MOST likely cause given the error: the IAM policy does not include permissions for dms:CreateEndpoint or dms:TestConnection. But the error is when starting the task, which may be due to missing permissions on the source endpoint. However, the best answer is that the IAM policy does not include the necessary permissions for the source endpoint. Option C is correct because DMS needs permissions to describe endpoints and test connections.

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 6

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 7

A company is deploying a new Amazon RDS for MySQL database. The security team requires that all data at rest be encrypted. What is the simplest way to meet this requirement?

Accepted Answer

Enable encryption at rest when creating the RDS instance using an AWS KMS key. Amazon RDS for MySQL supports encryption at rest using AWS KMS keys, which must be enabled at instance creation time because encryption cannot be added to an existing unencrypted RDS instance. Option C is correct because it describes the simplest and most direct method: enabling encryption at rest during the initial RDS instance creation with an AWS KMS key, which transparently encrypts the underlying storage, automated backups, read replicas, and snapshots.

Answer

Enable encryption using AWS Certificate Manager

Answer

Use client-side encryption in the application

Answer

Enable encryption at rest on the RDS instance after creation

Question 8

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). AWS DMS is the primary service for database migration with minimal downtime and ongoing replication. AWS SCT is used to convert the schema from SQL Server to RDS SQL Server (which may not need conversion) but more importantly to assess and convert any incompatible objects. However, for a like-to-like migration (SQL Server to SQL Server), SCT may not be required, but the question says 'migrating' and 'ongoing changes', so DMS is necessary. For minimal downtime, DMS uses Change Data Capture (CDC). To use CDC on SQL Server, you need to enable it, and SCT can help with schema conversion if needed. But the best pair is DMS and SCT because SCT can help with any schema incompatibilities and DMS handles data. Option A (DMS + SCT) is the standard recommendation for heterogeneous and homogeneous migrations. Option B (DMS + Snowball) is for large initial loads, but with 1 TB and minimal downtime, DMS alone may suffice. Option C (SCT + Snowball) doesn't include DMS for ongoing replication. Option D (DMS + Direct Connect) is about network, not a service. Option E (DMS + Lambda) is not typical. So correct is A and B? Wait: The question asks for TWO services. The typical best practice for minimal downtime is to use DMS with ongoing replication. For large databases, you might use Snowball for initial load and then DMS for CDC. So DMS and Snowball is a valid combination. Also DMS and SCT is also valid for schema conversion. Which two are correct? The question is 'Which TWO' and there are exactly two correct. I'll set correct options as A and B, but need to ensure exactly two. I'll make A: DMS and SCT, B: DMS and Snowball. Both are valid. But the stem says 'must support ongoing changes', so DMS is needed. SCT is for schema conversion, which may be needed but not always. Snowball is for initial load. Both are valid. I'll choose A and B as correct. Explanation: DMS is required for ongoing replication; SCT helps with schema conversion; Snowball helps with initial load for large databases.

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 9

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. Multi-AZ deployment automatically creates a standby instance in a different AZ. Automated backups are enabled by default and stored across multiple AZs. Retaining automated backups for 35 days provides point-in-time recovery. Read replicas are for read scaling, not high availability. Manual snapshots are for long-term retention, not high availability. Multi-Region replication is for disaster recovery, not high availability.

Answer

Take manual snapshots daily

Answer

Create a read replica in a different Availability Zone

Question 10

A company is migrating a MySQL database to Amazon Aurora MySQL. The migration must be completed with minimal downtime. Which TWO methods can achieve this? (Choose two.)

Accepted Answer

Create an Aurora MySQL read replica from the external MySQL instance using binlog replication. Using an Aurora read replica from an external MySQL instance is possible via the MySQL binlog replication, but it requires setting up replication from on-premises to Aurora. This is a valid method for minimal downtime. Creating an Aurora clone is for cloning existing Aurora clusters, not migration. Using DMS with ongoing replication is the standard approach. Taking a snapshot and restoring requires downtime. Enabling binlog replication is part of setting up a read replica. So correct are B and D. Option A: clone is not for migration. Option C: snapshot restore requires downtime. Option E: binlog replication alone is not a migration method; it's a configuration step.

Answer

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

Answer

Create an Aurora clone from the source database

Answer

Enable binlog replication on the source MySQL instance

Question 11

A company is migrating a 3 TB PostgreSQL database from on-premises to Amazon RDS for PostgreSQL. The migration must have minimal downtime. The on-premises network bandwidth to AWS is 1 Gbps. The database supports a critical application that cannot be stopped for more than 30 minutes. The migration team has set up AWS DMS with ongoing replication using CDC. The initial full load is expected to take 8 hours. During the migration, the DMS task fails with an error indicating that the source database's transaction log is being cleaned before DMS can capture changes. The source database has a transaction log retention period of 24 hours. The migration team notices that the CDC phase falls behind during peak hours. What should the team do to complete the migration successfully within the downtime window?

Accepted Answer

Increase the transaction log retention period on the source database and use a larger DMS replication instance. The issue is that DMS cannot keep up with changes during peak hours, causing the transaction logs to be cleaned before DMS reads them. Increasing the source database's transaction log retention period gives DMS more time to catch up. Using a larger DMS replication instance will increase processing capacity. Option C is the best combination. Option A (Snowball) would take too long. Option B (Direct Connect) doesn't solve the log retention issue. Option D (decrease retention) makes the problem worse.

Answer

Use AWS Snowball to transfer the full database and then use DMS for CDC

Answer

Increase the network bandwidth using AWS Direct Connect

Answer

Decrease the transaction log retention period to free up space

Question 12

A company is deploying a new web application on AWS. The application uses Amazon RDS for MySQL as its database. The database must be highly available and automatically failover in the event of an AZ outage. The company also needs to offload read traffic from the primary database to improve performance. The application read-to-write ratio is 80:20. The database workload is variable, with occasional spikes. The company wants a cost-effective solution that scales read capacity automatically. The operations team has limited experience with AWS. Which solution should the company implement?

Accepted Answer

Deploy an Amazon Aurora MySQL cluster with Multi-AZ and enable Aurora Auto Scaling for read replicas. Multi-AZ provides automatic failover. Read replicas offload read traffic. However, read replicas do not auto-scale automatically; you need to add replicas manually or use auto-scaling with a custom solution. But given limited experience, the simplest solution is to use Multi-AZ and one or more read replicas. Option C (Multi-AZ with read replicas and Application Auto Scaling) is the most complete, but Application Auto Scaling for read replicas requires custom metrics. Option D (Aurora with Auto Scaling) is simpler because Aurora Auto Scaling automatically adds/removes read replicas based on CPU or connections. Aurora is MySQL-compatible and provides better performance and scalability. For limited experience, Aurora is a better choice. Option A (Multi-AZ only) does not offload reads. Option B (Read replicas only) lacks automatic failover. So the best is D.

Answer

Deploy an RDS for MySQL instance with Multi-AZ and one or more read replicas, and use Application Auto Scaling to add replicas based on CPU utilization

Answer

Deploy an RDS for MySQL instance with Multi-AZ and enable automatic scaling of the instance size

Answer

Deploy an RDS for MySQL instance with multiple read replicas and use a custom script to promote a read replica in case of failure

Question 13

A company is migrating a 500 GB Oracle database to Amazon RDS for Oracle. The migration must be completed within 24 hours with minimal downtime. The on-premises network bandwidth is 1 Gbps. The migration team plans to use AWS DMS with ongoing replication. During the initial load, the DMS task fails with an error indicating that the source database is experiencing high CPU utilization. The source database is a production system serving live traffic. The team needs to reduce the impact on the source database while still meeting the migration deadline. Which approach should the team take?

Accepted Answer

Reduce the number of tables loaded in parallel in the DMS task and schedule the migration during off-peak hours. The issue is that DMS is consuming too many resources on the source. Reducing the number of tables loaded in parallel and scheduling the migration during off-peak hours will reduce CPU impact. Option B is the most balanced. Option A (increase DMS instance size) would increase source CPU usage. Option C (change to full load only) would require downtime. Option D (use Snowball) may not meet the 24-hour deadline due to shipping time.

Answer

Change the DMS task to perform only full load and skip ongoing replication

Answer

Increase the size of the DMS replication instance to speed up the migration

Answer

Use AWS Snowball to transfer the data offline and then use DMS for ongoing replication

Question 14

A company is migrating a 2 TB PostgreSQL database from on-premises to Amazon RDS for PostgreSQL. The migration must have minimal downtime and support ongoing replication. Which AWS service should be used for the migration?

Accepted Answer

AWS Database Migration Service (DMS) with change data capture. Option A is correct because AWS DMS supports ongoing replication from on-premises PostgreSQL to RDS for PostgreSQL using logical replication. Option B is wrong because S3 is for storage, not database migration. Option C is wrong because Snowball is for large data transfer offline, not minimal downtime replication. Option D is wrong because Database Migration Service is the correct name, not Data Migration Service.

Answer

AWS S3 Transfer Acceleration for direct database export

Answer

AWS Data Migration Service with AWS Glue

Answer

AWS Snowball Edge for offline data transfer

Question 15

A developer needs to deploy an Amazon RDS for MySQL DB instance that is accessible only from a specific EC2 instance in a VPC. Which configuration ensures this?

Accepted Answer

Place the RDS instance in the same VPC as the EC2 instance and configure a security group inbound rule referencing the EC2 security group. Option C is correct because placing the RDS instance in the same VPC and using a security group that allows inbound traffic from the EC2 instance's security group ensures restricted access. Option A is wrong because public accessibility would expose the DB to the internet. Option B is wrong because a network ACL applies at subnet level, not instance level. Option D is wrong because an IAM role does not control network access.

Answer

Use an IAM role to allow the EC2 instance to connect to the RDS instance

Answer

Enable public accessibility and assign a public IP to the RDS instance

Answer

Place RDS and EC2 in different subnets and configure a network ACL