DBS-C01 Deployment and Migration Practice Test 12 — 15 Questions

Question 1

A company is migrating a 5 TB Oracle database to Amazon Aurora PostgreSQL. The migration must be completed within a weekend. The on-premises network has a 1 Gbps connection to AWS. What is the MOST efficient migration strategy?

Accepted Answer

Use AWS Snowball Edge to transfer the data and then load into Aurora. Option B is correct because AWS Snowball Edge can transfer the data offline faster than over a 1 Gbps link (5 TB at 1 Gbps would take ~11 hours, but with overhead and network issues, Snowball is more reliable). Option A is wrong because DMS over 1 Gbps may not complete within a weekend for 5 TB with limited bandwidth. Option C is wrong because S3 Transfer Acceleration does not help with database migration to Aurora directly. Option D is wrong because Aurora does not support direct export from Oracle.

Answer

Use AWS S3 Transfer Acceleration to upload the database dump to S3 and then load into Aurora

Answer

Use AWS DMS with direct connect to export the Oracle database directly to Aurora

Answer

Use AWS DMS with change data capture over the existing network connection

Question 2

An administrator needs to migrate an on-premises MongoDB database to Amazon DocumentDB. The migration must have near-zero downtime. Which approach should the administrator use?

Accepted Answer

Use AWS DMS with MongoDB as source and DocumentDB as target. Option B is correct because AWS DMS supports ongoing replication from MongoDB to DocumentDB using change streams. Option A is wrong because mongodump/mongorestore is a one-time import with downtime. Option C is wrong because AWS DataSync is for file-based transfers, not databases. Option D is wrong because AWS Glue is for ETL, not live replication.

Answer

Use AWS DataSync to transfer the MongoDB data files

Answer

Use AWS Glue to extract and load data

Answer

Use mongodump to export and mongorestore to import

Question 3

A company wants to deploy a highly available Amazon RDS for MySQL database across two Availability Zones. Which feature should be enabled?

Accepted Answer

Multi-AZ deployment. Option A is correct because Multi-AZ deployment provides automatic failover to a standby in a different AZ. Option B is wrong because read replicas are for read scaling, not high availability. Option C is wrong because automatic backups are for point-in-time recovery. Option D is wrong because Enhanced Monitoring provides metrics, not HA.

Answer

Read replicas in a different AZ

Answer

Automated backups with retention

Answer

Enhanced Monitoring

Question 4

An administrator is setting up an AWS DMS replication instance and attaches the IAM policy shown in the exhibit. The administrator receives an error that the replication instance cannot be created. Which missing permission is the MOST likely cause?

Accepted Answer

ec2:DescribeSecurityGroups. Option C is correct because DMS replication instances require permission to describe security groups to validate network configuration. Option A is wrong because the policy already includes ec2:CreateNetworkInterface. Option B is wrong because ec2:DescribeVpcs is already present. Option D is wrong because dms:CreateReplicationInstance is missing, but the error is about replication instance creation, not tasks; however, the most specific missing permission is ec2:DescribeSecurityGroups.

Answer

ec2:DescribeVpcPeeringConnections

Answer

ec2:CreateNetworkInterfacePermission

Answer

dms:CreateReplicationInstance

Question 5

A company is migrating a 500 GB SQL Server database to Amazon RDS for SQL Server. The migration must minimize downtime and support ongoing replication. Which TWO AWS services should be used together?

Accepted Answer

AWS Database Migration Service (DMS). Options A and D are correct. AWS DMS can perform ongoing replication, and AWS SCT can convert the schema and assess any incompatibilities. Option B is wrong because Snowball is for offline transfer, not minimal downtime. Option C is wrong because RDS does not support native SQL Server replication as a target. Option E is wrong because Lambda is not needed for migration.

Answer

AWS Lambda

Answer

AWS Snowball Edge

Answer

AWS RDS SQL Server native backup and restore

Question 6

A company is deploying a new Amazon RDS for PostgreSQL DB instance. Which THREE actions are recommended for a secure deployment?

Accepted Answer

Enable encryption at rest using AWS KMS. Options A, C, and D are correct. Enabling encryption at rest, using private subnets, and enabling automated backups are security best practices. Option B is wrong because deleting automated backups immediately after creation removes the ability to perform point-in-time recovery. Option E is wrong because using the default VPC may not be properly isolated.

Answer

Use the default VPC for simplicity

Answer

Delete automated backups after the initial snapshot to reduce costs

Question 7

A company is migrating a 10 TB Oracle data warehouse to Amazon Redshift. The migration must minimize data transfer costs and ensure data integrity. Which TWO steps should the company take?

Accepted Answer

Use AWS Schema Conversion Tool (SCT) to convert the Oracle schema to Redshift. Options A and D are correct. AWS SCT can assess the schema and convert it for Redshift. AWS Snowball Edge can transfer the large dataset offline to reduce network costs. Option B is wrong because DMS may incur high network costs and time. Option C is wrong because Redshift Spectrum queries data in S3, not for migration. Option E is wrong because Kinesis is for streaming, not for bulk migration.

Answer

Use AWS DMS to replicate data directly over the internet

Answer

Use Amazon Kinesis Data Streams to stream data to Redshift

Answer

Use Amazon Redshift Spectrum to query data in S3 after loading

Question 8

An administrator is deploying an Amazon RDS for MySQL DB instance and needs to ensure that all connections use SSL. Which parameter should be set on the RDS DB instance?

Accepted Answer

Set require_secure_transport=ON in the DB parameter group. Option A is correct because setting require_secure_transport to ON in the DB parameter group forces SSL connections. Option B is wrong because rds.force_ssl is not a valid parameter; the correct MySQL parameter is require_secure_transport. Option C is wrong because ssl_cipher is for specifying ciphers, not enforcing SSL. Option D is wrong because tls_version sets the minimum TLS version, but does not enforce SSL.

Answer

Set ssl_cipher in the DB parameter group

Answer

Set tls_version in the DB parameter group

Answer

Set rds.force_ssl=1 in the DB parameter group

Question 9

A company needs to deploy a globally distributed application with a database that supports multi-region writes and automatic conflict resolution. Which AWS database service should be used?

Accepted Answer

Amazon DynamoDB Global Tables. Option D is correct because Amazon DynamoDB Global Tables supports multi-region writes and automatic conflict resolution. Option A is wrong because RDS for MySQL Multi-AZ is single-region. Option B is wrong because Aurora Global Database is for reads, not writes in multiple regions. Option C is wrong because ElastiCache is a cache, not a primary database.

Answer

Amazon Aurora Global Database

Answer

Amazon RDS for MySQL with Multi-AZ

Answer

Amazon ElastiCache for Redis

Question 10

An administrator runs the CLI command shown in the exhibit and sees the output. The DB instance 'mydb' is currently running MySQL 5.7.22. What does the output indicate?

Accepted Answer

The DB instance has a pending minor version upgrade to 5.7.23. Option A is correct because the PendingModifiedValues show EngineVersion 5.7.23, indicating a pending minor version upgrade. Option B is wrong because the parameter group is the default, not custom. Option C is wrong because the password is pending modification, but the question asks about the version. Option D is wrong because the output does not show a failure.

Answer

The master user password has been changed

Answer

The DB instance has failed to apply modifications

Answer

The DB instance is using a custom DB parameter group

Question 11

A company is migrating a 2 TB Oracle database to Amazon Aurora PostgreSQL. The on-premises database is 2 TB and the network link is 1 Gbps. The migration must complete within 48 hours with minimal data loss. The DBA has extracted the schema using AWS SCT and created an Aurora cluster. The DBA now needs to transfer the data. The DBA tried using AWS DMS over the network but estimates it will take 72 hours due to network overhead. The DBA also considered using an AWS Snowball Edge device but is concerned about the time to order and ship the device. Which approach should the DBA take to meet the deadline?

Accepted Answer

Use AWS Snowball Edge to transfer the database dump and then use DMS for change data capture. Option C is correct. The DBA should use AWS DMS with CDC to start the migration, then use a Snowball Edge for the initial load to reduce time. However, given the 48-hour window, using DMS with CDC and compressing data may still be too slow. Option B is actually the best: use Snowball Edge for initial load (which can be ordered and shipped quickly if available in region) and then DMS for CDC. But the correct answer according to best practices is to use DMS with CDC and optimize network (e.g., using compression, increasing instance size). However, the scenario suggests DMS alone is too slow. The best answer is to use Snowball Edge for the full load and DMS for CDC, as Snowball can transfer 2 TB quickly once received. Option A is wrong because it abandons CDC. Option B is correct because it combines Snowball for bulk and DMS for ongoing changes. Option C is wrong because it only uses DMS. Option D is wrong because it uses S3 only.

Answer

Use AWS DMS with change data capture and optimize the network by enabling compression

Answer

Use AWS S3 to upload the database dump and then load into Aurora

Answer

Use AWS DMS to perform a full load and then stop replication, accepting some data loss

Question 12

A company is deploying a new Amazon RDS for SQL Server DB instance with Multi-AZ. The database will be used by a critical application that requires minimal downtime during failover. The application uses a single connection string with the CNAME of the RDS endpoint. During a recent failover test, the application experienced a 3-minute timeout. The DBA wants to reduce the failover time. The current RDS instance is db.r5.large with 100 GB gp2 storage. The application is hosted on EC2 in the same VPC. Which change would MOST effectively reduce the failover time?

Accepted Answer

Configure the application to use a low TTL for DNS lookups and implement connection retries. Option A is correct because Multi-AZ failover typically completes within 1-2 minutes; the 3-minute timeout may be due to DNS caching. Enabling TTL=5 on the application side for DNS lookups can reduce failover time. Option B is wrong because increasing instance size does not directly reduce failover time. Option C is wrong because Provisioned IOPS does not reduce failover time. Option D is wrong because read replicas do not provide automatic failover.

Answer

Change the storage to Provisioned IOPS (io1)

Answer

Change the instance type to db.r5.xlarge

Answer

Use a read replica with automatic failover

Question 13

A startup is deploying a new web application on AWS. The application uses Amazon RDS for PostgreSQL as its database. The developers need to create the initial schema and load test data. They have a SQL script file that creates tables and inserts 10,000 rows. The DB instance is a db.t3.micro with 20 GB gp2 storage. The developers connect to the RDS instance using pgAdmin from their local machine and run the script. The script fails with a 'connection reset' error after inserting 5,000 rows. What is the MOST likely cause?

Accepted Answer

The DB instance ran out of memory or CPU credits due to the intensive script. Option A is correct because the db.t3.micro instance has limited memory and CPU credits; a large script can exhaust resources and cause a connection reset. Option B is wrong because the storage is 20 GB and 10,000 rows of test data are small. Option C is wrong because security group timeout is not typical for a connection reset. Option D is wrong because the default max_connections for db.t3.micro is typically sufficient for a single connection.

Answer

The max_connections parameter was set too low

Answer

The storage volume reached its maximum capacity

Answer

The security group blocked the connection due to a timeout

Question 14

A company is migrating a 5 TB PostgreSQL database from on-premises to Amazon RDS for PostgreSQL. The database has a 24/7 uptime requirement and must be migrated with minimal downtime. The on-premises network bandwidth is 100 Mbps. The migration must be completed within 48 hours. The team has chosen to use AWS Database Migration Service (DMS) with ongoing replication from a change data capture (CDC) source. After setting up the source endpoint, target endpoint, and replication instance, the initial full load takes 30 hours. However, during the CDC phase, the target falls behind by over 2 hours and continues to lag. The replication instance is a dms.c5.large (2 vCPUs, 4 GB memory). The source database is heavily utilized with frequent updates. What should the team do to reduce the CDC lag and meet the migration deadline?

Accepted Answer

Increase the replication instance size to dms.c5.2xlarge.. Option A is correct: increasing the replication instance size to dms.c5.2xlarge provides more CPU and memory, which can handle higher transaction throughput. Option B is wrong because splitting into multiple tasks adds overhead and may not help with a single source. Option C is wrong because DMS does not use Multi-AZ. Option D is wrong because disabling ongoing replication would cause data loss.

Answer

Enable Multi-AZ on the replication instance for better performance.

Answer

Split the migration into multiple DMS tasks for parallel processing.

Answer

Disable ongoing replication and use a one-time full load migration.

Question 15

An organization wants to migrate a 200 GB MySQL database from an on-premises server to Amazon Aurora MySQL. They have a 50 Mbps network connection. The database is 8 hours of downtime. The migration must be completed within 24 hours and costs must be minimized. The team decides to use AWS Database Migration Service (DMS). Which approach best meets the requirements?

Accepted Answer

Use AWS DMS with a full load and ongoing replication to minimize downtime.. Option B is correct: using a DMS full load with ongoing replication minimizes downtime and works within the network constraints. Option A is wrong because taking a dump over the network would take too long. Option C is wrong because using a larger instance is unnecessary and costly. Option D is wrong because using Snowball is overkill for 200 GB.

Answer

Create a mysqldump and transfer it over the network to S3, then restore to Aurora.

Answer

Use AWS Snowball Edge to transfer the data physically.

Answer

Provision a large EC2 instance to run a parallel export and import.