DBS-C01 Management and Operations Practice Test 9 — 15 Questions

Question 1

A company is migrating an on-premises Oracle database to Amazon RDS for Oracle. During the migration, they need to ensure minimal downtime. Which AWS service should be used for the migration?

Accepted Answer

AWS Database Migration Service. AWS Database Migration Service (DMS) is designed for minimal-downtime migrations, supporting continuous replication.

Answer

AWS DataSync

Answer

Amazon S3 Transfer Acceleration

Answer

AWS Server Migration Service

Question 2

A database administrator notices that an Amazon Aurora MySQL DB cluster's primary instance is experiencing high CPU utilization due to a long-running analytical query. The application can tolerate eventual consistency. What is the MOST cost-effective solution to reduce CPU load on the primary instance?

Accepted Answer

Configure an Auto Scaling policy for Aurora Replicas and modify the application to use the reader endpoint.. Offloading read queries to Aurora Replicas is cost-effective and reduces primary load without additional infrastructure.

Answer

Create a read replica in a different region and route read traffic there.

Answer

Increase the instance size of the primary instance.

Answer

Enable Aurora Parallel Query on the cluster.

Question 3

A company uses Amazon RDS for PostgreSQL with Multi-AZ deployment. They experience increased write latency during peak hours. The DB instance size is db.r5.large. Which action would MOST effectively reduce write latency?

Accepted Answer

Disable the Multi-AZ feature and use asynchronous replication with a read replica for failover.. Multi-AZ deployments use synchronous standby; enabling Multi-AZ with one standby reduces latency overhead compared to two standbys.

Answer

Switch to a db.r5.xlarge instance type.

Answer

Enable the synchronous_commit parameter to 'off'.

Answer

Enable Multi-AZ with two standby replicas.

Question 4

A company wants to automate the creation of a new Amazon RDS for SQL Server instance with specific configurations, including VPC, subnet, and security group settings. Which AWS service should be used to deploy this infrastructure as code?

Accepted Answer

AWS CloudFormation. AWS CloudFormation allows you to define infrastructure as code and automate resource creation.

Answer

AWS CodeDeploy

Answer

AWS Elastic Beanstalk

Answer

AWS OpsWorks

Question 5

A company runs an Amazon DynamoDB table with on-demand capacity. They notice that a specific partition key receives a high volume of read requests, causing throttling for that partition. What is the BEST solution to distribute the load evenly?

Accepted Answer

Add a random suffix to the partition key values to increase partition cardinality.. Adding a suffix to the partition key to create multiple partitions distributes read load across partitions.

Answer

Create a global secondary index with a different partition key.

Answer

Use DynamoDB Accelerator (DAX) to cache reads.

Answer

Switch the table to provisioned capacity with auto-scaling.

Question 6

A company uses Amazon RDS for MySQL with read replicas. The application writes to the primary and reads from the replicas. Occasionally, the application reads stale data from the replicas. Which action would ensure read-after-write consistency without impacting write performance?

Accepted Answer

Configure the application to read from the primary instance for critical queries.. Using the primary instance for reads that require consistency ensures the application reads the latest data. Session-level replication checks are not supported in standard MySQL.

Answer

Set the replica_read_consistency parameter to 'session'.

Answer

Use the reader endpoint and increase the replica lag threshold.

Answer

Enable the 'rds_set_replication_status' parameter on the read replicas.

Question 7

Which TWO AWS services can be used to monitor and set alarms on Amazon RDS database performance metrics? (Choose two.)

Accepted Answer

Amazon RDS Enhanced Monitoring. CloudWatch monitors metrics and can set alarms; Enhanced Monitoring provides OS-level metrics. RDS Performance Insights is for performance analysis, not alarms.

Answer

Amazon RDS Performance Insights

Answer

AWS Trusted Advisor

Answer

AWS CloudTrail

Question 8

Which THREE actions can be performed using the AWS CLI for Amazon Aurora? (Choose three.)

Accepted Answer

Create a DB cluster from a snapshot using 'aws rds restore-db-cluster-from-snapshot'. All three are valid AWS CLI actions for Aurora. RestoreDBClusterFromS3 is for MySQL, but it exists.

Answer

Change the storage type of an Aurora cluster using 'aws rds modify-db-instance'

Answer

Enable auto-scaling for Aurora Replicas using 'aws rds enable-autoscaling'

Question 9

Which THREE factors should be considered when choosing between Amazon DynamoDB and Amazon RDS for a new application? (Choose three.)

Accepted Answer

Need for ACID transactions across multiple rows. Option A is correct because Amazon RDS supports ACID transactions across multiple rows using traditional SQL databases like MySQL or PostgreSQL, which is essential for applications requiring strict consistency (e.g., financial systems). Amazon DynamoDB, while supporting ACID transactions via the TransactGetItems and TransactWriteItems APIs, is optimized for single-item or limited multi-item operations and may not perform as well for complex multi-row transactional workloads. The need for ACID across multiple rows is a key differentiator favoring RDS.

Answer

Need for automatic failover in multiple AWS Regions

Answer

Data size exceeding 10 TB

Question 10

A company wants to ensure that their Amazon RDS for PostgreSQL database is automatically backed up every day and retains backups for 30 days. Which configuration should they use?

Accepted Answer

Enable automated backups with a retention period of 30 days.. Automated backups are enabled by default with a retention period of 1-35 days. Setting backup retention period to 30 days meets the requirement.

Answer

Set the backup retention period to 0 to disable automated backups and use manual snapshots.

Answer

Create a manual snapshot daily using AWS Backup.

Answer

Enable Multi-AZ deployment for automatic failover.

Question 11

A company is running a production Amazon RDS for MySQL Multi-AZ DB instance. The database experiences intermittent high latency and the CloudWatch 'ReadLatency' metric spikes during periods of heavy read traffic. The application uses a single database endpoint. What is the MOST effective way to reduce read latency without changing the application code?

Accepted Answer

Enable a Multi-AZ deployment with one or more readable standby replicas.. Option C is correct because enabling Multi-AZ with a read replica allows read traffic to be offloaded to the standby replica, reducing load on the primary and improving read latency, all without application changes. Option A is wrong because increasing instance size may help but is less cost-effective and doesn't specifically target read-heavy workloads. Option B is wrong because enabling Multi-AZ alone does not provide a separate read endpoint. Option D is wrong because Amazon RDS does not support sharding natively without application changes.

Answer

Implement database sharding across multiple RDS instances.

Answer

Enable Multi-AZ on the existing DB instance to provide a standby for failover.

Answer

Increase the DB instance class to a larger size.

Question 12

A company uses Amazon DynamoDB with on-demand capacity for a gaming leaderboard. During a promotional event, write traffic spikes 10x, causing occasional 'ProvisionedThroughputExceededException' errors. The application retries with exponential backoff, but latency increases. The team notices that the 'ThrottledWriteRequests' metric spikes. What is the MOST cost-effective solution to handle these unpredictable spikes?

Accepted Answer

Continue using on-demand capacity but ensure the table has no throttling.. Option D is correct because on-demand capacity automatically scales to handle traffic spikes, eliminating throttling without manual intervention, and is cost-effective for unpredictable workloads. Option A is wrong because while DAX reduces read latency, it does not help with write throttling. Option B is wrong because auto scaling requires setting min/max capacity and may not react fast enough to sudden spikes. Option C is wrong because implementing a queue adds complexity and latency, and is not the simplest solution.

Answer

Implement DynamoDB Accelerator (DAX) to reduce read load.

Answer

Switch to provisioned capacity with auto scaling configured for the expected peak.

Answer

Use an Amazon SQS queue to buffer write requests before DynamoDB.

Question 13

A company is migrating an on-premises Oracle database to Amazon RDS for Oracle. The database is 500 GB and has a 4-hour downtime window. Which AWS service should be used to perform the migration with minimal downtime?

Accepted Answer

AWS Database Migration Service (DMS). Option B is correct because AWS DMS supports ongoing replication to minimize downtime during migration. Option A is wrong because AWS Snowball is for large data transfers but does not support ongoing replication. Option C is wrong because S3 is not a migration tool. Option D is wrong because RDS does not natively support Oracle Data Pump directly; DMS is the recommended service.

Answer

Oracle Data Pump using Amazon RDS option groups

Answer

AWS Snowball Edge

Answer

Amazon S3 Transfer Acceleration

Question 14

A company has an Amazon Redshift cluster that is running slowly on complex queries. The cluster has 10 dc2.large nodes. The 'QueryDuration' metric shows high values for several queries. The team wants to improve performance without changing queries. Which action is MOST likely to help?

Accepted Answer

Enable Redshift Spectrum to offload queries to Amazon S3.. Option C is correct because Redshift Spectrum allows querying data directly in S3, offloading compute from the cluster. Option A is wrong because increasing WLM concurrency may actually slow down queries due to resource contention. Option B is wrong because adding more nodes can improve performance but may be overkill and more expensive. Option D is wrong because compression is for storage, not query performance.

Answer

Add more nodes of the same type to the cluster.

Answer

Enable compression on all columns.

Answer

Increase the workload management (WLM) concurrency level.

Question 15

A company runs a critical Amazon RDS for PostgreSQL database. They notice that the 'DiskQueueDepth' metric is consistently high and the 'FreeStorageSpace' is below 10%. The database is used for OLTP workloads. What is the MOST immediate action to take?

Accepted Answer

Modify the DB instance to increase allocated storage.. Option B is correct because increasing storage quickly avoids potential downtime and I/O throttling. Option A is wrong because switching to Provisioned IOPS addresses latency but not the storage shortage. Option C is wrong because adding a read replica does not increase storage on the primary. Option D is wrong because modifying the instance class may not address storage space.

Answer

Upgrade to a larger DB instance class.

Answer

Switch the instance to Provisioned IOPS storage.

Answer

Create a read replica to offload read traffic.