DBS-C01 Deployment and Migration Practice Test 26 — 15 Questions

Question 1

A company is migrating an on-premises Oracle database to Amazon RDS for Oracle. They need to minimize downtime. Which TWO actions should they take?

Accepted Answer

Set up AWS DMS with change data capture (CDC) from the source. Option A is correct because AWS Database Migration Service (DMS) with change data capture (CDC) continuously replicates ongoing changes from the on-premises Oracle source to the RDS target after the initial full load, allowing a short cutover window and thus minimizing downtime. Option C is correct because AWS Schema Conversion Tool (SCT) analyzes and converts the source Oracle schema, stored procedures, and other objects to be compatible with the RDS for Oracle target, catching incompatibilities before migration and preventing failed or delayed cutovers. Option B is not relevant because increasing allocated storage addresses capacity/IOPS, not migration downtime. Option D is wrong because Single-AZ reduces availability and does not simplify or improve replication for a minimal-downtime migration. Option E is wrong because disabling Oracle archivelog mode would break CDC/redo-based replication and risk data loss, not speed up a safe migration.

Answer

Increase the allocated storage on the target RDS instance to improve performance

Answer

Deploy the target RDS instance as a Single-AZ to simplify replication

Answer

Disable Oracle archivelog mode to speed up data transfer

Question 2

A company is migrating an on-premises PostgreSQL database to Amazon RDS for PostgreSQL. The database is 2 TB and has a sustained write rate of 150 MB/s. The migration must have minimal downtime. Which AWS service or tool should be used for the initial data load and ongoing replication?

Accepted Answer

Use AWS Database Migration Service (AWS DMS) with full load and ongoing replication. AWS DMS is the correct choice because it supports both a full load of the existing 2 TB database and ongoing change data capture (CDC) to replicate transactions with minimal downtime. DMS can handle sustained write rates of 150 MB/s by using appropriate instance sizing and tuning, and it provides built-in mechanisms for resumable loads and validation, which are critical for a large-scale migration with minimal downtime.

Answer

Use pg_dump and pg_restore

Answer

Use AWS Schema Conversion Tool (AWS SCT) to convert schema and AWS DMS for data migration

Answer

Use AWS S3 Transfer Acceleration to upload data to Amazon S3, then restore to RDS

Question 3

A company is deploying a new application that requires a relational database with automatic failover and cross-Region disaster recovery. The application is read-heavy and expects up to 10 GB of data. Which combination of AWS services should be used?

Accepted Answer

Amazon Aurora with Multi-AZ and an Aurora global database. Amazon Aurora with Multi-AZ provides high availability within a single Region, while Aurora Global Database enables cross-Region disaster recovery with typical replication latency of under one second. Aurora is optimized for read-heavy workloads and scales automatically, making it ideal for the 10 GB dataset and the application's requirements.

Answer

Amazon RDS for MySQL with Multi-AZ and a read replica in another Region

Answer

Amazon S3 with AWS Glue and Amazon Athena

Answer

Amazon DynamoDB with global tables

Question 4

A company is deploying a new microservices application on Amazon ECS. Each microservice needs its own database. Which AWS database service should be used to minimize operational overhead?

Accepted Answer

Amazon DynamoDB. Amazon DynamoDB is a fully managed NoSQL database that provides single-digit millisecond latency at any scale, making it ideal for microservices that each require their own isolated database. It eliminates operational overhead by handling hardware provisioning, setup, configuration, replication, and patching automatically, with no servers to manage. DynamoDB also supports on-demand capacity mode, which scales automatically based on traffic, perfectly aligning with the dynamic nature of microservices on Amazon ECS.

Answer

Amazon Aurora

Answer

Amazon Redshift

Answer

Amazon RDS for MySQL

Question 5

A company wants to migrate an on-premises MySQL database to Amazon RDS for MySQL with minimal downtime. The database is 500 GB and has moderate write activity. Which approach is MOST suitable?

Accepted Answer

Use AWS Database Migration Service (DMS) with a full load and ongoing replication.. AWS DMS with full load and ongoing replication is the most suitable approach because it supports continuous change data capture (CDC) from the on-premises MySQL source to the Amazon RDS target, enabling minimal downtime. The full load transfers the initial 500 GB dataset, while ongoing replication applies incremental changes until cutover, meeting the requirement for minimal downtime with moderate write activity.

Answer

Use mysqldump to export the database, then import into RDS.

Answer

Use AWS Server Migration Service (SMS) to migrate the database server.

Answer

Create a read replica of the on-premises database and promote it to RDS.

Question 6

A developer is configuring an RDS for PostgreSQL instance for a new application. The application requires automatic failover to a standby instance in a different Availability Zone. Which deployment option should be selected?

Accepted Answer

Deploy a Multi-AZ instance.. Multi-AZ deployment for RDS PostgreSQL automatically provisions and maintains a synchronous standby replica in a different Availability Zone. In the event of a failure or Availability Zone outage, Amazon RDS automatically fails over to the standby, providing high availability without manual intervention. This meets the requirement for automatic failover to a standby instance in a different AZ.

Answer

Deploy a Single-AZ instance with a read replica.

Answer

Deploy a Single-AZ instance and take frequent snapshots.

Answer

Deploy a Single-AZ instance with a cross-region read replica.

Question 7

A company is deploying a new web application on Amazon RDS for MySQL and expects read-heavy traffic. The database must be highly available. Which deployment approach meets these requirements?

Accepted Answer

Deploy a Multi-AZ instance and create read replicas.. Deploying a Multi-AZ RDS for MySQL instance provides automatic failover for high availability, while adding read replicas offloads read-heavy traffic from the primary instance, improving read scalability. Read replicas can be placed in different Availability Zones to further enhance resilience and read performance.

Answer

Deploy a Multi-AZ instance without read replicas.

Answer

Deploy a Single-AZ instance with a Multi-AZ read replica.

Answer

Deploy a Single-AZ instance and use ElastiCache for caching.

Question 8

Refer to the exhibit. A developer runs the command against an RDS MySQL instance. The application team reports that the database is experiencing high read latency during peak hours. The database is not currently in Multi-AZ. What is the MOST cost-effective way to reduce read latency?

Accepted Answer

Create a read replica in the same region.. Creating a read replica in the same region offloads read traffic from the primary RDS MySQL instance, reducing read latency during peak hours without incurring the cost of a larger instance or a full Aurora migration. Read replicas are asynchronous and can serve SELECT queries, providing a cost-effective scaling solution for read-heavy workloads.

Answer

Enable Multi-AZ to distribute reads to the standby.

Answer

Upgrade the instance to db.r5.2xlarge.

Answer

Migrate to Aurora MySQL with a read replica.

Question 9

A company is migrating a 500 GB on-premises Oracle database to Amazon RDS for Oracle. The migration must have minimal downtime. Which AWS service should be used for the initial data load and ongoing replication?

Accepted Answer

AWS Database Migration Service (AWS DMS). AWS Database Migration Service (AWS DMS) is the correct choice because it supports both full-load migration of the initial 500 GB Oracle database and ongoing change data capture (CDC) replication to keep the target RDS for Oracle instance synchronized with minimal downtime. DMS uses Oracle LogMiner or binary reader to capture changes from the source redo logs and apply them continuously, enabling a near-zero downtime migration.

Answer

AWS Snowball Edge for offline data transfer

Answer

Amazon S3 to store backup files and restore

Answer

AWS DataSync

Question 10

A company wants to migrate a 10 TB Microsoft SQL Server database from on-premises to Amazon RDS for SQL Server. The migration must be completed within a week and minimize network bandwidth usage. Which approach is most suitable?

Accepted Answer

Use AWS Snowball Edge to transfer backup files, then restore to RDS. AWS Snowball Edge is the most suitable approach because it allows you to transfer the 10 TB database backup files physically, bypassing the internet entirely. This eliminates network bandwidth constraints and ensures the migration can be completed within a week, as the data is shipped to AWS and then restored to Amazon RDS for SQL Server using native restore operations.

Answer

Back up the database to Amazon S3 using AWS CLI

Answer

Set up AWS Direct Connect and use DMS

Answer

Use AWS DMS over the internet

Question 11

A company is deploying a new multi-AZ Amazon RDS for PostgreSQL database. The security team requires that all traffic to the database be encrypted in transit. Which configuration ensures this?

Accepted Answer

Enable SSL/TLS and require client connections to use SSL. Enabling SSL/TLS on the RDS instance and requiring client connections to use SSL ensures that all data transmitted between clients and the database is encrypted in transit. This is achieved by setting the rds.force_ssl parameter to 1 in the DB parameter group, which enforces SSL/TLS for all connections, meeting the security team's requirement for encryption in transit.

Answer

Use a customer master key (CMK) for RDS

Answer

Place the RDS instance in a public subnet

Answer

Enable encryption at rest using AWS KMS

Question 12

A company is deploying a MongoDB-compatible database using Amazon DocumentDB. The application requires the ability to perform ad-hoc queries on nested fields within documents. Which DocumentDB feature should be enabled to meet this requirement?

Accepted Answer

Indexes on nested fields. Amazon DocumentDB supports indexing on nested fields, which allows efficient querying of sub-documents and arrays within documents. By creating indexes on specific nested paths (e.g., "address.city"), the query engine can perform index scans instead of full collection scans, enabling fast ad-hoc queries on nested fields. This feature directly meets the requirement for ad-hoc queries on nested fields.

Answer

TTL indexes

Answer

Transactions

Answer

Change streams

Question 13

A company needs to migrate a 2 TB PostgreSQL database from an on-premises data center to Amazon Aurora PostgreSQL. The network bandwidth is limited to 100 Mbps. The migration window is 5 days. Which approach is most cost-effective and likely to succeed?

Accepted Answer

Use AWS DMS with a VPN connection to the on-premises database. AWS DMS with a VPN connection can handle the migration of 2 TB over 100 Mbps within 5 days. At 100 Mbps, the theoretical maximum transfer is about 1.08 TB per day (100 Mbps * 86400 seconds / 8 bits per byte / 1024^3), so 2 TB would take roughly 1.85 days of continuous transfer, well within the 5-day window. DMS supports ongoing replication to minimize downtime, and a VPN is cost-effective compared to Direct Connect for a one-time migration.

Answer

Set up AWS Direct Connect and use DMS

Answer

Use AWS Snowball Edge to transfer data offline

Answer

Export to Amazon S3 and import into Aurora

Question 14

A company is deploying an Amazon RDS for MySQL database in a VPC. The database must be accessible only from a specific set of application servers in the same VPC. Which configuration provides the most secure access?

Accepted Answer

Set the security group inbound rule to reference the security group of the application servers. Referencing the application servers' security group as the source in the RDS inbound rule allows traffic only from those specific instances, regardless of IP changes. This follows the AWS security best practice of using security group IDs for fine-grained, stateful access control within a VPC, eliminating reliance on static IP addresses or CIDR ranges.

Answer

Set the security group inbound rule to allow all traffic from the VPC CIDR

Answer

Place the RDS instance in a separate subnet group

Answer

Set the RDS instance to publicly accessible

Question 15

A company is deploying Amazon DynamoDB for a new application. The application requires single-digit millisecond latency for read operations. Which DynamoDB feature should be configured to meet this requirement?

Accepted Answer

DynamoDB Accelerator (DAX). DynamoDB Accelerator (DAX) is an in-memory caching service that sits between your application and DynamoDB, providing microsecond to single-digit millisecond latency for read-heavy workloads. By caching frequently accessed items, DAX offloads read traffic from the underlying DynamoDB tables, ensuring consistent low-latency responses even under high concurrency.

Answer

DynamoDB Streams

Answer

Auto Scaling

Answer

Time to Live (TTL)