DBS-C01 Deployment and Migration Practice Test 22 — 15 Questions

Question 1

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.. AWS DMS requires archive logging on the source Oracle database to capture ongoing changes for continuous replication. Archive logging ensures that redo logs are retained and available for DMS to read transaction changes after a log switch, enabling Change Data Capture (CDC) without data loss.

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 2

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 3

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 4

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 allows near-zero downtime by continuously replicating changes from the source to the target RDS instance. DMS can handle unlogged tables by converting them to logged tables during migration, as DMS requires logical replication which relies on write-ahead logs. AWS SCT can help assess and convert custom PostgreSQL extensions to RDS-compatible equivalents or suggest alternatives. Option B (pg_dump/pg_restore) is an offline approach that would cause significant downtime, which does not meet the minimal downtime requirement. Option C (copy to S3 then restore) is not a supported migration method for PostgreSQL to RDS. Option D (streaming replication) is not feasible because RDS does not accept direct streaming replication from an external source, and unlogged tables cannot be replicated via streaming. Therefore, A is the best strategy.

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 5

A company is migrating a 2 TB Oracle database to Amazon Aurora PostgreSQL. They need to minimize downtime and ensure data consistency. Which migration strategy should they use?

Accepted Answer

Use AWS DMS with ongoing replication (change data capture) from Oracle to Aurora.. AWS DMS with ongoing replication (change data capture) is the correct strategy because it allows continuous synchronization of changes from the source Oracle database to the target Aurora PostgreSQL, minimizing downtime to just the final cutover window. This approach ensures data consistency by applying transactional changes in near real-time, which is essential for a 2 TB database where a full load alone would require a lengthy maintenance window and risk data divergence.

Answer

Use AWS DMS with full load only, then cut over during a maintenance window.

Answer

Export the database to Amazon S3 using Oracle Data Pump, then import into Aurora.

Answer

Use pg_dump to export the database and pg_restore to import into Aurora.

Question 6

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.

Question 7

A company is migrating a 1 TB SQL Server database to Amazon RDS for SQL Server. They want to use the native backup and restore feature. What must they do first?

Accepted Answer

Upload the backup file to an Amazon S3 bucket.. To use the native backup and restore feature for migrating a SQL Server database to Amazon RDS, you must first upload the backup file to an Amazon S3 bucket. RDS for SQL Server supports restoring from backup files stored in S3 via the `RESTORE DATABASE` command, using the `FROM URL` option that references the S3 bucket. This is the only supported method for native restore, as RDS does not allow direct file system access or FTP transfers.

Answer

Store the backup file on an EBS volume attached to the RDS instance.

Answer

Use FTP to transfer the backup file directly to the RDS instance.

Answer

Use the AWS Management Console to upload the backup file to the RDS instance.

Question 8

A company is migrating a MongoDB database to Amazon DocumentDB. They have a 200 GB database and need to minimize downtime. Which migration approach is most appropriate?

Accepted Answer

Use AWS DMS to migrate data from MongoDB to DocumentDB.. AWS DMS with ongoing replication (change data capture) is the most appropriate migration approach for minimizing downtime when migrating a 200 GB MongoDB database to Amazon DocumentDB. DMS can perform an initial load and then continuously replicate ongoing changes from the source MongoDB to the target DocumentDB until cutover, resulting in near-zero downtime. Option B is incorrect because native MongoDB replication is not supported by DocumentDB; DocumentDB cannot join a MongoDB replica set.

Answer

Take an EBS snapshot of the MongoDB volume and restore it to DocumentDB.

Answer

Set up MongoDB replication from the source to DocumentDB, then promote DocumentDB.

Answer

Export the database using mongodump and import using mongorestore into DocumentDB.

Question 9

A company is planning to migrate a 5 TB Oracle data warehouse to Amazon Redshift. They need to transform the data during migration. Which AWS service should they use to perform the transformation?

Accepted Answer

AWS Glue to perform extract, transform, and load (ETL) jobs.. AWS Glue is the correct choice because it is a fully managed ETL service designed for data transformation and loading into Amazon Redshift. It can handle the 5 TB Oracle data warehouse migration by running Spark-based ETL jobs that transform the data before writing it to Redshift, making it ideal for batch-oriented data warehouse migrations.

Answer

Amazon Kinesis Data Analytics for real-time transformation.

Answer

Amazon Athena to query the source data and write results to Redshift.

Answer

AWS Database Migration Service (DMS) with transformation rules.

Question 10

A company is migrating a PostgreSQL database to Amazon RDS for PostgreSQL. They want to automate the deployment of the RDS instance using infrastructure as code. Which AWS service should they use?

Accepted Answer

AWS CloudFormation.. AWS CloudFormation is the correct service for automating the deployment of an RDS for PostgreSQL instance using infrastructure as code. It allows you to define the entire RDS instance configuration—including DB instance class, storage, backup retention, and security groups—in a declarative JSON or YAML template, which can be version-controlled and reused for consistent, repeatable deployments.

Answer

Amazon EC2 Auto Scaling.

Answer

AWS Management Console.

Answer

AWS Command Line Interface (CLI).

Question 11

A company is migrating a 100 GB Oracle database to Amazon RDS for Oracle. They want to use AWS DMS. The source database is in a different AWS account. What is required to allow DMS to connect to the source?

Accepted Answer

Establish VPC peering or VPN between the source and target VPCs, and configure security group rules.. AWS DMS requires network connectivity between the replication instance and the source database. Since the source is in a different AWS account, VPC peering or a VPN connection must be established to route traffic between the VPCs. Additionally, security group rules in both VPCs must allow inbound/outbound traffic on the Oracle listener port (default 1521) from the DMS replication instance's IP or security group.

Answer

Assign an IAM role to the source database to allow DMS access.

Answer

Configure an S3 VPC gateway endpoint for the source VPC.

Answer

Create a VPC endpoint for DMS in the source account.

Question 12

A company is migrating a 3 TB MySQL database to Amazon Aurora MySQL. They need to validate data consistency after migration. Which approach should they use?

Accepted Answer

Use AWS DMS data validation feature.. AWS DMS data validation feature is the correct approach because it automatically compares source and target records by computing checksums at the table level, ensuring end-to-end consistency without manual intervention. For a 3 TB migration, this built-in feature handles large-scale validation efficiently by validating ongoing replication and full-load data, which is critical for MySQL to Aurora MySQL migrations.

Answer

Compare row counts between source and target tables.

Answer

Run random SELECT queries on a subset of rows to compare values.

Answer

Compute MD5 checksums of the entire dataset in both databases.

Question 13

A company is migrating an on-premises DynamoDB table to Amazon DynamoDB in another AWS region. What is the most efficient method to migrate the data?

Accepted Answer

Use DynamoDB global tables to replicate data across regions.. DynamoDB global tables provide a fully managed, multi-region, multi-master replication solution that automatically replicates data across AWS regions with low latency. This eliminates the need for custom code or external tools, making it the most efficient method for migrating an on-premises DynamoDB table to another region, as it handles ongoing replication and conflict resolution natively.

Answer

Export the table to S3 using AWS Data Pipeline, then import into DynamoDB in the target region.

Answer

Set up DynamoDB Streams and write a custom consumer to replicate data to the target region.

Answer

Use AWS DMS to replicate data from on-premises to DynamoDB.

Question 14

A company is migrating a MySQL database to Amazon RDS for MySQL. They want to use AWS DMS for continuous replication. Which TWO prerequisites must be met before starting the migration?

Accepted Answer

Enable binary logging (binlog) on the source MySQL database.. AWS DMS uses MySQL's binary log (binlog) to capture ongoing changes for continuous replication (CDC). Enabling binlog on the source database is mandatory because DMS reads the binlog to identify insert, update, and delete operations after the initial full load. Without binlog enabled, DMS cannot perform change data capture and the migration will be limited to a one-time full load only.

Answer

Set the source database to read-only mode during migration.

Answer

Place the source database in a VPC.

Answer

Create an S3 bucket to store the migration logs.

Question 15

A company is migrating a 500 GB Oracle database to Amazon RDS for Oracle. They need to validate the migration and ensure data consistency. Which TWO methods should they use?

Accepted Answer

Use AWS DMS data validation feature.. AWS DMS data validation (Option B) is a built-in feature that automatically compares source and target records by computing checksums on each row, ensuring end-to-end data consistency without manual effort. Comparing row counts and checksums (Option D) is a standard manual validation technique that provides a reliable, independent verification of data completeness and integrity. Together, these two methods cover both automated and manual validation, which is critical for a 500 GB migration where manual inspection of every row is impractical.

Answer

Use Amazon S3 inventory reports on the exported data.

Answer

Run random SELECT queries on a subset of tables.

Answer

Use Amazon CloudWatch Logs to compare database logs.