DBS-C01 Deployment and Migration Practice Test 21 — 15 Questions

Question 1

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 Database Migration Service (AWS DMS) supports MongoDB as a source and Amazon DocumentDB as a target, enabling continuous replication with change data capture (CDC) for minimal downtime. MongoDB native tools (mongodump and mongorestore) are also valid for offline, one-time migrations by exporting the database as BSON files and importing them directly into DocumentDB.

Answer

AWS DataSync

Answer

Amazon S3

Answer

Amazon Kinesis Data Streams

Question 2

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 IAM policy explicitly allows the `rds:CreateDBInstance` action for the resource `arn:aws:rds:us-east-1:123456789012:db:my-database`. The Deny statement only applies to actions not listed in the Allow statement, but since the specific action and resource match the Allow, the user is permitted to create the DB instance. AWS IAM evaluates policies with an explicit Allow overriding an implicit Deny, and the Deny here does not block the allowed action.

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

Question 3

An IAM role with the above trust policy is created. The role is then attached to an EC2 instance. The application on the EC2 instance tries to create an RDS DB instance using the AWS SDK. What will happen?

Accepted Answer

The call will fail because the role's permissions policy does not allow rds:CreateDBInstance. The call will fail because the IAM role attached to the EC2 instance lacks a permissions policy (e.g., an identity-based policy) that explicitly grants the `rds:CreateDBInstance` action. The trust policy shown in the question only defines which principal (the EC2 service) can assume the role, not what actions the role can perform. Without a permissions policy allowing RDS operations, the SDK call is denied by default.

Answer

The call will succeed because the trust policy grants permissions to EC2

Answer

The call will succeed because the trust policy allows EC2 to create RDS instances

Answer

The call will fail because the trust policy does not include the RDS service

Question 4

An administrator runs the above AWS CLI command to create an RDS MySQL instance. The command completes successfully. What is the status of the new DB instance immediately after the command returns?

Accepted Answer

creating. When you run the AWS CLI command to create an RDS MySQL instance, the command returns immediately after the API call is accepted and the instance enters the 'creating' state. The instance is not yet available because provisioning, configuring, and booting the database engine takes several minutes. The 'creating' status indicates that AWS is actively setting up the DB instance, and it will transition to 'available' only after the entire creation process completes.

Answer

available

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stopped

Answer

deleting

Question 5

A company is migrating an on-premises MySQL database to Amazon RDS for MySQL. The database is 2 TB in size and the network bandwidth is 100 Mbps. The company needs to minimize downtime. Which migration strategy should be used?

Accepted Answer

Use AWS Database Migration Service (DMS) with ongoing replication.. AWS DMS with ongoing replication is the correct strategy because it allows you to perform a full load of the 2 TB database while simultaneously capturing ongoing changes from the source MySQL binlog. This minimizes downtime by enabling a cutover with only a brief pause to ensure replication lag is zero, rather than requiring a long period of application downtime for a full export and import.

Answer

Copy database files to Amazon S3, then restore to RDS using native restore.

Answer

Use mysqldump to export the database and import it into RDS.

Answer

Use AWS Server Migration Service to migrate the database server.

Question 6

A company is deploying a new multi-AZ Aurora MySQL database. The application requires read-heavy workloads and low latency. Which configuration will best meet these requirements?

Accepted Answer

Enable Aurora Auto Scaling with a target metric of average CPU utilization.. Aurora Auto Scaling dynamically adds reader instances based on the average CPU utilization metric, which directly addresses the read-heavy workload requirement by distributing read traffic across multiple replicas. This configuration ensures low latency by scaling out read capacity automatically as demand increases, without manual intervention.

Answer

Enable Multi-AZ and use the secondary for read traffic.

Answer

Deploy a single instance with one read replica in the same AZ.

Answer

Use an RDS Proxy in front of the database.

Question 7

A company is migrating a 5 TB Oracle database to Amazon RDS for Oracle. The database has several large tables with LOB columns. The migration must have minimal downtime. Which approach should be taken?

Accepted Answer

Use AWS DMS with LOB support and ongoing replication from Oracle to RDS.. AWS DMS with LOB support and ongoing replication (change data capture, CDC) is the correct approach because it enables a near-zero downtime migration by continuously replicating changes from the source Oracle database to Amazon RDS for Oracle after an initial full load. DMS handles large LOB columns efficiently using its 'Full LOB mode' or 'Limited LOB mode' settings, which are critical for tables with LOB data. The combination of full load + CDC ensures minimal downtime, as the target remains synchronized until cutover.

Answer

Use Oracle GoldenGate to replicate data to RDS.

Answer

Use Oracle Data Pump to export the database and import into RDS.

Answer

Copy the database files to Amazon S3 and use the rdsadmin.rds_restore_from_s3 procedure.

Question 8

A company needs to migrate a SQL Server database to Amazon RDS for SQL Server. The database uses stored procedures with xp_cmdshell. What should the company do?

Accepted Answer

Rewrite the stored procedures to remove dependency on xp_cmdshell before migration.. Amazon RDS for SQL Server does not support the xp_cmdshell extended stored procedure because it allows execution of operating system commands, which violates the managed service model where AWS controls the host OS. The correct approach is to rewrite the stored procedures to remove dependency on xp_cmdshell before migration, using alternatives such as SQL Server Agent jobs, CLR integration, or external scripting via AWS Lambda or EC2.

Answer

Use RDS Custom for SQL Server to retain full control.

Answer

Enable xp_cmdshell in the RDS parameter group.

Answer

Disable xp_cmdshell in the stored procedures and migrate as-is.

Question 9

A company is deploying a new DynamoDB table for a global application. The table must have low latency reads and writes across multiple AWS regions. Which configuration should be used?

Accepted Answer

Use DynamoDB global tables with replicate streams.. DynamoDB global tables provide a fully managed, multi-region, multi-master solution that automatically replicates data across selected AWS Regions, enabling low-latency reads and writes globally. By enabling DynamoDB Streams on the table, global tables use the streams to capture item-level changes and replicate them to other regions, ensuring eventual consistency and high availability for global applications.

Answer

Enable DynamoDB Accelerator (DAX) in each region.

Answer

Use DynamoDB Accelerator (DAX) with cross-region replication.

Answer

Create a single table in the primary region and use Amazon CloudFront for reads.

Question 10

A company is migrating a PostgreSQL database to Amazon RDS for PostgreSQL. The source database uses custom functions written in PL/Python. What should the company consider?

Accepted Answer

Rewrite the functions in PL/pgSQL or another supported language.. Amazon RDS for PostgreSQL does not support PL/Python because it requires the installation of an untrusted procedural language, which poses security risks in a managed database environment. The correct approach is to rewrite the custom functions in a supported language such as PL/pgSQL, PL/Perl, or PL/Tcl, which are trusted languages available in RDS for PostgreSQL.

Answer

Modify the DB parameter group to enable PL/Python.

Answer

Use RDS Custom for PostgreSQL to install PL/Python.

Answer

Migrate to Aurora PostgreSQL which supports PL/Python.

Question 11

A company is migrating a 10 TB MongoDB database to Amazon DocumentDB. The migration must have minimal downtime. Which strategy should be used?

Accepted Answer

Use AWS DMS with MongoDB as source and DocumentDB as target, with change data capture.. AWS DMS with MongoDB as source and DocumentDB as target, using change data capture (CDC), is the correct strategy because it enables a live migration with minimal downtime. DMS performs an initial full load of the 10 TB database and then continuously replicates ongoing changes from the MongoDB oplog, allowing you to cut over to DocumentDB with only a brief pause.

Answer

Use mongodump to export the database and mongorestore to import into DocumentDB.

Answer

Use AWS CloudEndure to replicate the MongoDB server to DocumentDB.

Answer

Copy the database files to Amazon S3 and restore to DocumentDB.

Question 12

A company is deploying a new RDS for MySQL database and needs to ensure that connections are encrypted using TLS. Which parameter should be configured?

Accepted Answer

Set the rds.force_ssl parameter to 1 in the DB parameter group.. In Amazon RDS for MySQL, the `rds.force_ssl` parameter must be set to 1 in the DB parameter group to enforce TLS/SSL for all connections. This parameter, when enabled, requires clients to use SSL/TLS encryption when connecting to the database instance, ensuring data in transit is encrypted.

Answer

Set the ssl_ca parameter to the RDS CA certificate.

Answer

Set the require_secure_transport parameter to ON.

Answer

Set the tls_version parameter to TLSv1.2.

Question 13

A company is migrating an on-premises Oracle database to Amazon RDS for Oracle using AWS DMS. The migration fails with an error indicating that DMS cannot capture changes from the source because the archive log mode is not enabled. What should be done?

Accepted Answer

Enable archive log mode on the source Oracle database.. D is correct because AWS DMS requires archive log mode to be enabled on the source Oracle database for ongoing replication (CDC). Without archive logs, DMS cannot capture the redo data needed to apply changes to the target. Enabling archive log mode ensures the redo logs are preserved and accessible for change data capture.

Answer

Disable ongoing replication and perform a full load only.

Answer

Set up an Oracle Data Guard standby and use it as the source.

Answer

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

Question 14

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

Accepted Answer

Use AWS DMS with ongoing replication from the source.. AWS DMS with ongoing replication (change data capture, CDC) is a valid method for migrating to Amazon RDS for SQL Server with minimal downtime because it allows you to perform a full load of the database and then continuously replicate incremental changes from the source until you cut over. This keeps the target nearly in sync, reducing the downtime window to seconds or minutes.

Answer

Use AWS CloudEndure to replicate the entire server.

Answer

Copy the database files to Amazon S3 and restore to RDS.

Answer

Use SQL Server Import/Export Wizard.

Question 15

Which THREE factors should be considered when choosing between Amazon RDS and Amazon DynamoDB for a new application? (Choose THREE.)

Accepted Answer

The query patterns and access methods required by the application.. The choice between Amazon RDS (relational) and DynamoDB (NoSQL) hinges on the application's data access patterns. RDS supports complex SQL queries with joins, aggregations, and secondary indexes, while DynamoDB is optimized for key-value and document queries with predictable, low-latency access patterns. If the application requires flexible querying with ad-hoc filters, RDS is appropriate; if it needs high-throughput, single-key lookups or simple query patterns, DynamoDB is better suited.

Answer

The requirement for encryption at rest.

Answer

The need for multi-AZ high availability.