DBS-C01 Deployment and Migration Practice Test 7 — 15 Questions

Question 1

A company is migrating a 10 TB PostgreSQL database from on-premises to Amazon RDS for PostgreSQL. They need to minimize downtime and have limited network bandwidth. Which approach is most appropriate?

Accepted Answer

Use AWS Snowball to transfer a physical backup to AWS, then use DMS for ongoing replication.. Using AWS DMS for ongoing replication after a full load is the standard approach to minimize downtime. Snowball is suitable for large initial loads over limited bandwidth, but ongoing replication still requires DMS. Using only DMS replication may take too long for the initial load over slow bandwidth. pg_dump/pg_restore requires downtime during the dump and restore.

Answer

Use AWS Database Migration Service (DMS) with a full load and ongoing replication to keep the target in sync.

Answer

Use pg_dump to export the database and pg_restore to import to RDS, then use DMS for replication.

Answer

Use AWS Direct Connect to increase bandwidth and then use DMS for full load and replication.

Question 2

A company wants to migrate an on-premises SQL Server database to Amazon RDS for SQL Server. They need to convert stored procedures and functions. Which AWS service should they use?

Accepted Answer

AWS SCT. AWS SCT helps convert database schema and code objects like stored procedures from one engine to another (including SQL Server to RDS for SQL Server for compatibility checks). DMS handles data migration, not schema conversion. CloudEndure is for server migration. Snowball is for offline data transfer.

Answer

AWS CloudEndure Migration

Answer

AWS DMS

Answer

AWS Snowball

Question 3

A company is deploying a new web application that uses Amazon RDS for MySQL. To improve read performance, they add a read replica. However, the application reports stale data. What is the most likely cause?

Accepted Answer

The replication is asynchronous and there is replication lag.. Amazon RDS for MySQL uses asynchronous replication for read replicas. The primary instance commits writes and then sends the binary log (binlog) events to the replica, which applies them. This asynchronous nature introduces replication lag, meaning the replica may not have the most recent writes. If the application reads from the replica before the lag is resolved, it will see stale (older) data.

Answer

The application is using a connection pool that caches connections to the primary.

Answer

The read replica is in a different AWS Region.

Answer

The application is reading from the replica before the write is committed on the primary.

Question 4

A company is migrating a 5 TB MongoDB database to Amazon DocumentDB. They have a short maintenance window and need to minimize downtime. Which migration strategy should be used?

Accepted Answer

Use AWS DMS to perform a full load and then ongoing replication from the source MongoDB.. AWS DMS supports MongoDB as a source and Amazon DocumentDB as a target, enabling a full load of the 5 TB database followed by ongoing change data capture (CDC) using MongoDB's oplog. This minimizes downtime by keeping the target nearly synchronized during the migration window, allowing a final cutover with minimal interruption.

Answer

Use the MongoDB change streams feature to replicate changes to DocumentDB in real time.

Answer

Set up AWS Direct Connect to the source and use mongorestore directly to DocumentDB.

Answer

Export the data using mongodump, transfer to Amazon S3, and import using mongorestore.

Question 5

A company is planning to deploy an Amazon RDS for PostgreSQL instance. Which of the following is a required step to enable automated backups?

Accepted Answer

Set the backup retention period to a value greater than 0.. Automated backups are enabled by default with a retention period of 7 days. No additional setup is required. Encryption is optional. Multi-AZ is optional. Maintenance window is set by default.

Answer

Set a preferred maintenance window.

Answer

Enable encryption at rest.

Answer

Configure a Multi-AZ deployment.

Question 6

A company is migrating an on-premises Oracle database to Amazon RDS for Oracle. They want to use Oracle GoldenGate for replication. Which AWS service can be used to simplify the setup of GoldenGate on AWS?

Accepted Answer

AWS Marketplace. AWS DMS can use Oracle GoldenGate as a source or target when configured, but it's not a managed GoldenGate service. AWS Marketplace offers pre-configured GoldenGate images. EC2 can be used to install GoldenGate manually. RDS does not support installing GoldenGate directly.

Answer

AWS DMS

Answer

Amazon RDS for Oracle with GoldenGate enabled

Answer

AWS CloudFormation

Question 7

A company is deploying a new application that requires a globally distributed database with low latency reads. They choose Amazon DynamoDB global tables. What is a key consideration for this deployment?

Accepted Answer

Each replica can serve reads and writes independently.. DynamoDB global tables use active-active replication with eventual consistency. Writes are replicated asynchronously. Strongly consistent reads are only supported in the region where the write occurred. Each replica can handle reads and writes. Table class is not region-specific.

Answer

Writes are synchronously replicated to all regions.

Answer

The table class must be DynamoDB Standard-Infrequent Access.

Answer

Global tables support strongly consistent reads from any region.

Question 8

A company is migrating an on-premises MySQL database to Amazon RDS for MySQL. Which TWO AWS services can assist in assessing the source database for compatibility issues?

Accepted Answer

AWS Database Migration Service (DMS). AWS SCT can assess source schema for compatibility with RDS. AWS DMS can assess data types and conversion issues as part of its task validation. Trusted Advisor is for cost optimization, not database compatibility. CloudWatch is for monitoring. Inspector is for security assessment.

Answer

AWS Trusted Advisor

Answer

Amazon CloudWatch

Answer

Amazon Inspector

Question 9

A company is migrating a 2 TB SQL Server database to Amazon RDS for SQL Server. They have a limited maintenance window and need to minimize downtime. Which TWO strategies should they combine?

Accepted Answer

Use AWS DMS to perform a full load and ongoing replication.. Using DMS for full load and ongoing replication minimizes downtime. AWS SCT is needed to convert schema if there are incompatibilities. Snowball is for offline transfer, but with 2 TB and limited time, DMS online is better. Direct Connect improves network but is not a migration strategy. CloudEndure is for server migration.

Answer

Use AWS Direct Connect to increase bandwidth.

Answer

Use AWS CloudEndure Migration.

Answer

Use AWS Snowball to transfer a backup offline.

Question 10

A company is deploying an Amazon Aurora MySQL database with read replicas. They need to ensure high availability and disaster recovery across AWS Regions. Which THREE components should be included?

Accepted Answer

Aurora Replicas in the same Region. Aurora Replicas in the same Region provide read scaling and automatic failover within an AWS Region. They share the same underlying storage volume as the primary instance, so failover is fast (typically under 30 seconds) and does not require data rehydration. This is a core component for high availability within a single Region.

Answer

Auto Scaling groups

Answer

Amazon CloudFront

Question 11

A company is migrating a 500 GB Oracle database to Amazon Aurora PostgreSQL. Which THREE steps should be part of the migration plan?

Accepted Answer

Use AWS DMS to perform a full load and ongoing replication from Oracle to Aurora.. Using SCT for schema conversion is necessary because Oracle and PostgreSQL have different syntax. DMS can migrate data with ongoing replication. After migration, testing is crucial to ensure functionality. Direct Connect is optional. Snowball may be overkill for 500 GB. S3 is used for backup storage but not a required step.

Answer

Use AWS Snowball to transfer the database files.

Answer

Set up AWS Direct Connect between on-premises and AWS.

Question 12

Refer to the exhibit. A developer wants to connect to the database. Which database engine is most likely being used?

Accepted Answer

MySQL. The output shows port 3306, which is the default port for MySQL and MariaDB. Amazon RDS for MySQL uses port 3306. Aurora MySQL also uses 3306, but the endpoint pattern is RDS, not Aurora-specific. PostgreSQL uses 5432, Oracle uses 1521, SQL Server uses 1433.

Answer

Oracle

Answer

SQL Server

Answer

PostgreSQL

Question 13

Refer to the exhibit. An IAM policy is attached to a user. The user attempts to create an RDS DB instance named 'new-prod-db' with Oracle Standard Edition Two engine. What will happen?

Accepted Answer

The request will fail because the Deny condition matches the engine.. The policy has an Allow for db names starting with 'new-' and a Deny for Oracle engine. Since there is an explicit Deny for Oracle, the request will be denied due to the Deny override. The Allow does not apply because the Deny is more specific and takes precedence.

Answer

The request will fail because there is no Allow for 'new-prod-db'.

Answer

The request will succeed because the Allow matches the name pattern.

Answer

The request will succeed because the Deny is not effective for 'new-prod-db'.

Question 14

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

Accepted Answer

AWS DMS. Option C is correct because AWS Database Migration Service (DMS) supports ongoing replication from on-premises to RDS with minimal downtime. Option A is wrong because S3 is for storage, not database migration. Option B is wrong because Snowball is for large data transfer, not ongoing replication. Option D is wrong because RDS does not support native pglogical replication from on-premises easily.

Answer

AWS Snowball Edge

Answer

AWS S3

Answer

RDS native PostgreSQL logical replication

Question 15

A company wants to migrate a 500 GB SQL Server database to Amazon RDS for SQL Server with the least amount of downtime. The on-premises network has a 1 Gbps connection to AWS. Which approach should be used?

Accepted Answer

Use AWS DMS with ongoing replication from on-premises to RDS. Option B is correct because AWS DMS with ongoing replication allows for minimal downtime by keeping the target in sync until cutover. Option A is wrong because native backup/restore requires downtime during the restore. Option C is wrong because S3 is not a direct migration path. Option D is wrong because Snowball requires shipping time and is not minimal downtime.

Answer

Use AWS Snowball to transfer the database backup, then restore to RDS

Answer

Copy database files to S3 and then use RDS import

Answer

Use native SQL Server backup to S3, then restore to RDS