DBS-C01 Deployment and Migration Practice Test 19 — 15 Questions

Question 1

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.

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Amazon Aurora

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Amazon Redshift

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Amazon RDS for MySQL

Question 2

A company is migrating an on-premises PostgreSQL database to Amazon RDS for PostgreSQL. The database is 2 TB and the migration must have minimal downtime. Which TWO AWS services should be used together to accomplish this?

Accepted Answer

AWS Schema Conversion Tool (AWS SCT). AWS Schema Conversion Tool (AWS SCT) is used to convert the source PostgreSQL schema and objects to be compatible with Amazon RDS for PostgreSQL, handling any heterogenous elements. AWS Database Migration Service (AWS DMS) then performs the continuous data replication from the on-premises database to RDS, enabling minimal downtime by keeping the target in sync until a cutover.

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AWS CloudFormation

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AWS DataSync

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AWS CloudEndure Migration

Question 3

A company is deploying a new application on AWS that requires a highly available relational database with automatic failover and read scaling. The database size is 100 GB and the workload is balanced between reads and writes. Which THREE AWS services or features should be used?

Accepted Answer

Multi-AZ deployment. Multi-AZ deployment (Option A) is correct because it provides automatic failover for Amazon RDS by provisioning a synchronous standby replica in a different Availability Zone. If the primary DB instance fails, Amazon RDS automatically fails over to the standby, ensuring high availability without manual intervention. This directly meets the requirement for automatic failover in a relational database scenario.

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DynamoDB Accelerator (DAX)

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Amazon RDS Proxy

Question 4

A company is migrating an on-premises MySQL database to Amazon RDS for MySQL. The database is 500 GB and the migration must have minimal downtime. Which TWO AWS services should be used together to accomplish this?

Accepted Answer

AWS Database Migration Service (AWS DMS). AWS DMS (Option D) is correct because it is purpose-built for migrating databases with minimal downtime by continuously replicating changes from the source to the target using change data capture (CDC). AWS SCT (Option E) is correct because it assesses the source MySQL schema and automatically converts any incompatible objects (e.g., storage engines, functions) to be compatible with Amazon RDS for MySQL, ensuring a smooth migration. Together, they enable a near-zero-downtime migration by first performing a full load via DMS and then applying ongoing CDC replication until cutover.

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AWS App2Container

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AWS CloudFormation

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AWS DataSync

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.

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

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

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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.

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Deploy a Single-AZ instance with a read replica.

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Deploy a Single-AZ instance and take frequent snapshots.

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

Question 7

A company is migrating a 2 TB Oracle database to Amazon Aurora PostgreSQL using AWS DMS. The migration is taking longer than expected, and the ongoing replication lag is increasing. Which action would MOST likely improve the migration speed?

Accepted Answer

Increase the DMS replication instance size.. Increasing the replication instance size (Option C) directly addresses the root cause of slow migration and increasing replication lag: insufficient compute or network resources on the DMS instance. A larger instance provides more CPU, memory, and network bandwidth, enabling faster full-load processing and more efficient ongoing replication. This is the most effective action when the instance is resource-constrained, which is common with a 2 TB database.

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Enable parallel load on the DMS task.

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Decrease the DMS task's batch size and commit interval.

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Disable the DMS task's logging to reduce overhead.

Question 8

A company is planning to migrate a MongoDB database to Amazon DocumentDB. The database has several sharded collections. Which migration strategy should be used?

Accepted Answer

Use AWS DMS with MongoDB as source and DocumentDB as target, enabling ongoing replication.. AWS DMS supports MongoDB as a source and Amazon DocumentDB as a target, and it can perform ongoing replication (change data capture) to keep the target synchronized with the source during migration. This is essential for sharded MongoDB collections because it minimizes downtime by allowing the source to remain operational while data is migrated and changes are continuously applied.

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Set up MongoDB replica set to replicate directly to DocumentDB.

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Use AWS Schema Conversion Tool (SCT) to convert the schema, then manually migrate data.

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Export data using mongodump and import using mongorestore.

Question 9

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.

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Deploy a Multi-AZ instance without read replicas.

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

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

Question 10

A company is migrating a 1 TB SQL Server database to Amazon RDS for SQL Server using backup and restore. The database has high transaction volume. Which backup type should be used to minimize downtime?

Accepted Answer

Perform a full backup, then transaction log backups, and restore the full backup with the last log backup.. A full backup followed by transaction log backups allows point-in-time recovery and minimizes downtime during migration. You restore the full backup to RDS, then apply the latest transaction log backup to capture all changes up to the migration cutover, ensuring data consistency without requiring the database to be offline for the entire duration.

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Perform only transaction log backups and restore them to RDS.

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Perform a differential backup and restore it to RDS.

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Perform a full backup and restore it to RDS.

Question 11

A company is migrating a self-hosted Cassandra cluster to Amazon Keyspaces (for Apache Cassandra). The cluster has 10 nodes and handles 50,000 writes per second. Which migration strategy is MOST efficient?

Accepted Answer

Set up Keyspaces as a new datacenter in the existing Cassandra cluster using native replication.. Setting up Amazon Keyspaces as a new datacenter in the existing Cassandra cluster using native replication allows for a live, zero-downtime migration. Cassandra's native replication protocol handles the 50,000 writes per second incrementally, automatically replicating data from the existing cluster to Keyspaces without requiring an export/import step or additional ETL tools.

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Export data using CQL COPY and import into Keyspaces.

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Use AWS Glue to extract data from Cassandra and write to Keyspaces.

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Use AWS DMS with Cassandra as source and Keyspaces as target.

Question 12

A company wants to deploy a DynamoDB table that requires consistent single-digit millisecond latency regardless of traffic spikes. Which DynamoDB capacity mode should be selected?

Accepted Answer

On-demand capacity mode.. On-demand capacity mode is the correct choice because it automatically scales read and write capacity up and down based on actual traffic, eliminating the need for capacity planning and ensuring consistent single-digit millisecond latency even during unpredictable traffic spikes. This mode is designed for workloads with variable or bursty traffic patterns where latency sensitivity is critical.

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DynamoDB Accelerator (DAX) enabled.

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Provisioned capacity mode with auto scaling.

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Provisioned capacity mode with fixed read/write capacity.

Question 13

A company is migrating a 5 TB PostgreSQL database to Amazon Aurora PostgreSQL. The database has complex stored procedures and triggers. The migration must be completed within a 30-minute downtime window. Which approach would meet the requirement?

Accepted Answer

Use AWS DMS with full load and ongoing replication, then perform a cutover.. AWS DMS with full load and ongoing replication allows you to migrate the 5 TB database with minimal downtime by continuously replicating changes from the source PostgreSQL to the target Aurora PostgreSQL. When you are ready, you perform a cutover, which typically takes only a few minutes, meeting the 30-minute downtime window. The complex stored procedures and triggers are handled because DMS supports ongoing replication for PostgreSQL, capturing DML and DDL changes.

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Use Database Migration Service (DMS) with validation only.

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Use AWS SCT to convert the schema and then use pg_dump/pg_restore.

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Set up an Aurora read replica from the source PostgreSQL.

Question 14

A company is migrating a 200 GB Oracle database to Amazon RDS for Oracle. Which TWO steps should be taken to ensure a successful migration? (Choose two.)

Accepted Answer

Use AWS DMS with full load and ongoing replication.. AWS DMS supports both homogeneous and heterogeneous migrations, and for a 200 GB Oracle database, using full load plus ongoing replication minimizes downtime by continuously applying changes from the source to the target RDS instance. This approach is ideal for migrating large databases with minimal disruption.

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Enable TDE encryption on the source database before migration.

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Use AWS DMS only for heterogeneous migrations; use Oracle Data Pump instead.

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Export the database using expdp and import using impdp.

Question 15

A company is deploying a new MySQL database on Amazon RDS. The database must be highly available and support cross-Region disaster recovery. Which TWO actions should be taken? (Choose two.)

Accepted Answer

Create a cross-region read replica.. A cross-region read replica provides a secondary copy of the database in a different AWS Region, which can be promoted to a standalone primary in a disaster scenario, enabling cross-Region disaster recovery. Option E is correct because Multi-AZ deployment provides automatic failover within a single region by synchronously replicating data to a standby instance in a different Availability Zone, ensuring high availability. Together, these two actions satisfy both high availability (within-region failover) and cross-Region DR requirements.

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Enable encryption at rest using AWS KMS.

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Deploy a Multi-AZ instance in multiple regions.

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Enable automated backups with a retention period of 35 days.