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

Question 1

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. Amazon Aurora provides high availability and read scaling with its cluster architecture. Read replicas can be added for read scaling. Multi-AZ deployment ensures automatic failover. Option A and C are correct; Option D is correct because Aurora itself provides Multi-AZ storage. Option B (RDS Proxy) is for connection pooling, not failover. Option E (DAX) is for DynamoDB caching.

Answer

DynamoDB Accelerator (DAX)

Answer

Amazon RDS Proxy

Question 2

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 provides data migration with ongoing replication, and AWS SCT can help convert schema if needed, but for homogeneous migration, DMS alone is sufficient. However, the combination is commonly used. Option C (CloudFormation) is for provisioning. Option D (DataSync) is for file transfer. Option E (App2Container) is for containerization.

Answer

AWS App2Container

Answer

AWS CloudFormation

Answer

AWS DataSync

Question 3

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.. Option C is correct because AWS DMS with ongoing replication allows continuous data synchronization from on-premises to RDS, enabling a cutover with minimal downtime. Option A is wrong because taking a snapshot of the on-premises database and restoring to RDS would require downtime during backup and restore, and does not capture ongoing changes. Option B is wrong because AWS Database Migration Service (DMS) supports homogeneous migrations like MySQL to MySQL, not just heterogeneous. Option D is wrong because exporting to a dump file and importing requires downtime and does not handle ongoing writes.

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 4

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.. Option B is correct because Multi-AZ deployment provides automatic failover to a standby in a different AZ. Option A is wrong because read replicas are for read scaling, not automatic failover. Option C is wrong because a single-AZ deployment lacks failover. Option D is wrong because RDS does not have a 'Cross-Region Standby' deployment option; Cross-Region Read Replicas are for disaster recovery but don't provide automatic failover.

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 5

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.. Option D is correct because increasing the DMS instance size provides more CPU and memory, directly improving replication speed. Option A is wrong because parallel load is used for full load, not ongoing replication. Option B is wrong because reducing batch size may actually increase overhead. Option C is wrong because disabling logging is not recommended and may cause data loss.

Answer

Enable parallel load on the DMS task.

Answer

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

Answer

Disable the DMS task's logging to reduce overhead.

Question 6

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.. Option A is correct because AWS DMS supports MongoDB as a source and DocumentDB as a target for continuous migration. Option B is wrong because mongodump/mongorestore does not handle sharding well and requires downtime. Option C is wrong because DocumentDB does not support native replication from MongoDB. Option D is wrong because DocumentDB does not have a sharding feature like MongoDB.

Answer

Set up MongoDB replica set to replicate directly to DocumentDB.

Answer

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

Answer

Export data using mongodump and import using mongorestore.

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.. Option C is correct because Multi-AZ provides high availability and read replicas offload read traffic. Option A is wrong because it lacks read scaling. Option B is wrong because it lacks high availability. Option D is wrong because Multi-AZ only provides high availability, not read scaling.

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

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.. Option C is correct because a full backup followed by transaction log backups allows restoring to a point in time, minimizing data loss and downtime. Option A is wrong because only full backup requires longer downtime during restore and may lose transactions. Option B is wrong because differential backup alone is not sufficient; you need a full backup chain. Option D is wrong because transaction log backup alone cannot restore without a full backup.

Answer

Perform only transaction log backups and restore them to RDS.

Answer

Perform a differential backup and restore it to RDS.

Answer

Perform a full backup and restore it to RDS.

Question 9

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.. Option A is correct because using native Cassandra replication allows seamless migration with zero downtime by adding Keyspaces as a new datacenter. Option B is wrong because DMS does not support Cassandra as a source for Keyspaces. Option C is wrong because CQL COPY is not suitable for high throughput writes and requires downtime. Option D is wrong because S3 export/import is a batch process, not real-time.

Answer

Export data using CQL COPY and import into Keyspaces.

Answer

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

Answer

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

Question 10

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.. Option D is correct because on-demand mode automatically scales to handle traffic spikes while maintaining latency. Option A is wrong because provisioned mode can throttle if capacity is exceeded. Option B is wrong because provisioned with auto scaling still has a maximum capacity. Option C is wrong because global tables are for multi-region replication, not for handling spikes.

Answer

DynamoDB Accelerator (DAX) enabled.

Answer

Provisioned capacity mode with auto scaling.

Answer

Provisioned capacity mode with fixed read/write capacity.

Question 11

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.. Option B is correct because AWS DMS with ongoing replication can keep the target in sync and then perform a cutover within minutes. Option A is wrong because AWS SCT is for schema conversion, not data migration. Option C is wrong because Aurora native replication only works from Aurora to Aurora. Option D is wrong because pg_dump/pg_restore would take longer than 30 minutes for 5 TB.

Answer

Use Database Migration Service (DMS) with validation only.

Answer

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

Answer

Set up an Aurora read replica from the source PostgreSQL.

Question 12

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.. Options B and D are correct. Using AWS SCT helps convert the schema and identify potential issues. Using AWS DMS with ongoing replication minimizes downtime. Option A is wrong because Oracle to RDS for Oracle is homogeneous; DMS supports it. Option C is wrong because manual export/import is error-prone and causes downtime. Option E is wrong because encrypting the source database adds complexity and may not be necessary.

Answer

Enable TDE encryption on the source database before migration.

Answer

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

Answer

Export the database using expdp and import using impdp.

Question 13

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.. Options A and C are correct. Enabling Multi-AZ provides high availability within a region. Creating a cross-region read replica provides disaster recovery. Option B is wrong because automated backups are for point-in-time recovery, not cross-region DR. Option D is wrong because RDS does not support Multi-Region Multi-AZ. Option E is wrong because encryption is for security, not HA or DR.

Answer

Enable encryption at rest using AWS KMS.

Answer

Deploy a Multi-AZ instance in multiple regions.

Answer

Enable automated backups with a retention period of 35 days.

Question 14

A company is migrating a 3 TB SQL Server database to Amazon RDS for SQL Server. The migration must have minimal downtime and support point-in-time recovery after migration. Which THREE steps should be included in the migration plan? (Choose three.)

Accepted Answer

Take a full backup of the source database.. Options A, C, and E are correct. Full backup with transaction log backups allows point-in-time recovery and minimal downtime during restore. AWS DMS can be used for ongoing replication. Option B is wrong because differential backup alone does not allow point-in-time recovery. Option D is wrong because snapshot backup is not native to SQL Server and RDS does not support restoring from native snapshots.

Answer

Take a snapshot backup of the source database.

Answer

Take a differential backup.

Question 15

A company is deploying a DynamoDB table for a global application that requires low-latency reads and writes in multiple AWS Regions. Which THREE features should be enabled? (Choose three.)

Accepted Answer

DynamoDB Accelerator (DAX).. Options A, C, and D are correct. DynamoDB global tables provide multi-region replication. DAX provides in-memory caching for low-latency reads. On-demand capacity handles traffic spikes. Option B is wrong because TTL is for data expiration, not performance. Option E is wrong because Streams are for change data capture, not low-latency access.

Answer

DynamoDB Streams.

Answer

Time to Live (TTL).