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

Question 1

A company is moving a self-hosted MySQL database to Amazon Aurora MySQL. The current database uses InnoDB with full-text indexes and triggers. The migration must be done with zero downtime. Which approach meets these requirements?

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

Accepted Answer

Use AWS DMS with ongoing replication from the source MySQL database. AWS DMS with ongoing replication (change data capture) allows continuous synchronization from the source MySQL database to Amazon Aurora MySQL, enabling a zero-downtime migration. DMS captures incremental changes from the source's binary logs (binlog) and applies them to the target, so the database remains fully operational during the migration. This approach also supports InnoDB tables, full-text indexes, and triggers, as DMS handles schema and data replication for these features. Option C (native MySQL binlog replication) is supported by Aurora MySQL, but it requires an initial seed of data which introduces downtime because the source database typically needs to be in a read-only state for a consistent backup. In contrast, DMS with CDC avoids any initial downtime.

Answer

Use mysqldump to export the database and import into Aurora

Answer

Set up MySQL replication from on-premises to Aurora using native binlog replication

Answer

Export data to Amazon S3 and use Aurora's LOAD DATA FROM S3 command

Question 2

A company is migrating a 1 TB Oracle database to Amazon RDS for Oracle. The source database has a high volume of small transactions. The migration must minimize source database impact. Which AWS DMS configuration should be used?

Accepted Answer

Use full load only and disable ongoing replication. Using full load only with ongoing replication disabled minimizes source database impact by avoiding the overhead of capturing and applying continuous change data capture (CDC) logs. The high volume of small transactions would otherwise generate a large number of redo log switches and increase I/O on the source, which is contrary to the requirement to minimize impact. A full load only migration transfers a snapshot of the data once, reducing the source load to a single consistent read operation.

Answer

Use batch-optimized apply mode

Answer

Use full load with CDC (ongoing replication)

Answer

Use multiple DMS tasks to parallelize the migration

Question 3

Which THREE considerations are important when deploying Amazon Aurora Global Database? (Choose 3.)

Accepted Answer

Each secondary region can have up to 16 read replicas. Option B is correct because in an Aurora Global Database, each secondary region can contain up to 16 Aurora Replicas that serve read-only workloads, which is a key scalability consideration for the deployment. Option C is correct because the architecture works by creating cross-region read replicas in each secondary region, which replicate from the primary region's storage volume with minimal impact on the primary. Option E is correct because Aurora Global Database uses dedicated replication infrastructure that typically achieves sub-second (less than 1 second) replication latency between regions, which is a primary benefit for disaster recovery and low-latency global reads. Option A is incorrect because AWS DMS is not required; Aurora Global Database uses Aurora's native storage-based replication rather than DMS. Option D is incorrect because transaction logs are not stored in Amazon S3 for replication; Aurora uses its distributed, log-structured storage layer to replicate redo log records directly between regions.

Answer

AWS DMS must be used to set up replication

Answer

Amazon S3 is used to store transaction logs

Question 4

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 5

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 6

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 7

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 8

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 9

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 10

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.. Option D is correct because AWS Database Migration Service (AWS DMS) supports SQL Server as both source and target for Amazon RDS for SQL Server, and its ongoing replication (change data capture) capability continuously applies changes from the source to the target, enabling a cutover with minimal downtime. Option E is correct because RDS for SQL Server supports native backup and restore of .bak files to Amazon S3, and combining that with log shipping (restoring transaction log backups) keeps the RDS target nearly in sync with the on-premises source until cutover, achieving minimal downtime. Option A is not valid because AWS CloudEndure (now AWS Application Migration Service) performs whole-server replication for lift-and-shift of EC2 instances, not a database-level migration into RDS. Option B is not valid because you cannot simply copy database files (MDF/LDF) to S3 and restore them directly to RDS; RDS only accepts native .bak backups via the S3 native restore procedure. Option C is not valid because the SQL Server Import/Export Wizard performs a one-time data copy with no ongoing replication, so it cannot meet the minimal-downtime requirement.

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 11

Which TWO steps are required when migrating an Oracle database to Amazon RDS for Oracle using AWS DMS with ongoing replication? (Choose TWO.)

Accepted Answer

Enable archive logging on the source Oracle database.. Option C is correct because AWS DMS requires the source Oracle database to be in ARCHIVELOG mode so that redo log information is available for capturing ongoing changes during CDC replication. Option D is correct because DMS needs supplemental logging enabled at the database level (or at least for all columns of replicated tables) to capture the necessary before/after image data for ongoing replication. Option A is not required because SCT is used for schema conversion between heterogeneous engines, not for a homogeneous Oracle-to-RDS-for-Oracle migration. Option B is insufficient because minimal supplemental logging does not capture all the column-level change data DMS needs for ongoing replication. Option E is not required because a VPC endpoint is only needed for private connectivity to AWS services, not for DMS to reach an Oracle source and target.

Answer

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

Answer

Enable minimal supplemental logging.

Answer

Create a VPC endpoint for the DMS replication instance.

Question 12

Refer to the exhibit. A company wants to migrate this RDS MySQL instance to an Aurora MySQL cluster with encryption at rest. What is the most efficient approach?

Accepted Answer

Create a snapshot of the RDS instance, copy the snapshot with encryption, then restore to an Aurora cluster.. It is the most efficient approach to migrate an RDS MySQL instance to an encrypted Aurora MySQL cluster. You first create a snapshot of the RDS instance, then copy that snapshot with encryption enabled (using an AWS KMS key), and finally restore the encrypted snapshot to an Aurora cluster. This method ensures encryption at rest is applied during the migration without requiring additional data transfer or schema conversion.

Answer

Use AWS DMS to migrate the database to an encrypted Aurora cluster.

Answer

Create a snapshot of the RDS instance and restore it directly to an Aurora cluster.

Answer

Create an encrypted read replica in Aurora and promote it.

Question 13

Refer to the exhibit. A database administrator has this IAM policy attached to their user. They attempt to delete the database instance 'prod-mydb' but receive an 'AccessDenied' error. Why?

Accepted Answer

The Deny statement explicitly denies deletion of any instance with an identifier starting with 'prod-'.. The IAM policy includes an explicit Deny statement that denies the rds:DeleteDBInstance action when the resource ARN contains an instance identifier starting with 'prod-'. Explicit Deny statements override any Allow statements, so even if another policy allows deletion, this Deny blocks it for instances like 'prod-mydb'.

Answer

The policy does not allow the rds:DeleteDBInstance action for any resource.

Answer

The resource ARN in the Deny statement does not match the instance.

Answer

The user does not have permission to describe the DB instance.

Question 14

A company is running a production PostgreSQL database on an EC2 instance (db.m5.xlarge) with 500 GB of gp2 EBS storage. The database is used by a customer-facing application that requires low latency. The company plans to migrate this database to Amazon RDS for PostgreSQL with minimal downtime. The current database has a high write load with frequent updates and deletes, and the table sizes are growing. The company also wants to enable Multi-AZ for high availability and use read replicas for reporting workloads. During migration planning, they discover that the source database has several large unlogged tables and uses custom PostgreSQL extensions that are not available in RDS. Which migration strategy should the company use to minimize downtime and meet all requirements?

Accepted Answer

Use AWS DMS with ongoing replication, convert unlogged tables to logged tables, and migrate custom extensions using AWS SCT.. AWS DMS with ongoing replication provides continuous data synchronization from the source PostgreSQL database to RDS, minimizing downtime during cutover. Unlogged tables must be converted to logged tables because RDS does not support unlogged tables, and AWS SCT can migrate custom extensions by converting them to equivalent RDS-supported extensions or providing workarounds. This strategy addresses all requirements: minimal downtime, Multi-AZ, read replicas, and handling of unlogged tables and custom extensions.

Answer

Use pg_dump to export the database and pg_restore to import into RDS, then set up read replicas.

Answer

Copy the database files to Amazon S3, then use the rdsadmin.rdsadmin_restore_from_s3 procedure to restore to RDS.

Answer

Set up PostgreSQL streaming replication from the EC2 instance to an RDS read replica, then promote the replica.

Question 15

A company wants to migrate an on-premises MySQL database to Amazon RDS for MySQL. The database is 500 GB and experiences heavy write traffic. They need to minimize downtime and ensure no data loss. Which approach should they take?

Accepted Answer

Set up MySQL replication from the on-premises database to RDS, then promote the RDS instance when ready.. Setting up native MySQL replication from the on-premises database to Amazon RDS for MySQL allows continuous synchronization with minimal downtime. When ready, you simply stop replication and promote the RDS instance, ensuring zero data loss since all transactions are replicated in near real-time.

Answer

Use AWS DMS with a full load task, then cut over the application to RDS.

Answer

Create an RDS read replica of the on-premises database, then promote it to a standalone instance.

Answer

Use mysqldump to export the database and mysql command to import into RDS during a maintenance window.