DBS-C01 Management and Operations Practice Test 20 — 15 Questions

Question 1

Refer to the exhibit. A database engineer runs the query above to troubleshoot an application error. The query returns no results even though the database is generating errors. What is the most likely reason?

Accepted Answer

The log stream format uses a different field name for the error message. Option D is correct because the query filters on the 'message' field, but the log stream format may have the error message in a different field. Option A is wrong because the query already uses case-insensitive matching. Option B is wrong because the log group configuration does not affect the query field names. Option C is wrong because the query does not specify a time range, but that would return results from the last 15 minutes by default.

Answer

The regex pattern does not match because it is case-sensitive

Answer

The query does not specify a time range, so no results are returned

Answer

The log group has not been configured to export to CloudWatch Logs

Question 2

Refer to the exhibit. A database engineer is assigned this IAM policy. Which of the following actions can the engineer perform? (Choose two.)

Accepted Answer

Describe all automated snapshots. Correct answers are B and D. B: The policy allows 'rds:DescribeDBSnapshots' for all resources. D: The policy allows 'rds:CreateDBSnapshot' for all resources, so creating a snapshot with any name is allowed. A is wrong because the Deny statement blocks deletion of snapshots with names starting with 'prod-'. C is wrong because the Deny specifically targets the 'prod-*' pattern. E is wrong because the Deny applies to snapshots in us-east-1 only? Actually the Deny resource is specific to us-east-1, but the question says 'in any region' - the policy's Deny applies only to us-east-1, so deletion in other regions is allowed? Wait, the resource ARN specifies us-east-1, so Deny only applies to snapshots in that region. But the question says 'prod-database-snapshot' - if it's in us-east-1, it's denied. However, the user is asking about 'a snapshot named prod-database-snapshot' - that matches the pattern. So C is wrong. E is wrong because the policy does not allow deletion of snapshots with prefix 'prod-'. The correct interpretation: The Deny only applies to the specific ARN with region us-east-1, so if the snapshot is in another region, deletion is allowed? But the policy does not explicitly allow deletion, so by default it's denied (unless there is an Allow). The policy only allows Create and Describe. Deletion is not allowed anywhere because there is no Allow statement for Delete. So deletion is implicitly denied for all snapshots. Wait, IAM default is deny. So without an explicit Allow for Delete, deletion is denied. So E is wrong. The correct answers are B and D.

Answer

Delete a manual snapshot named dev-snapshot

Answer

Delete a manual snapshot named prod-database-snapshot

Answer

Delete a manual snapshot named prod-backup

Question 3

Refer to the exhibit. A database engineer runs the command and receives the above output. The engineer wants to convert the database to Multi-AZ. Which command should be used?

Accepted Answer

aws rds modify-db-instance --db-instance-identifier mydb --multi-az. Option B is correct because 'modify-db-instance' with --multi-az is the correct AWS CLI command to enable Multi-AZ. Option A is wrong because 'create-db-instance' is for new instances, not modifying existing ones. Option C is wrong because 'reboot-db-instance' restarts the instance but does not change Multi-AZ. Option D is wrong because 'create-db-cluster' is for Aurora, not for converting a single DB instance to Multi-AZ.

Answer

aws rds reboot-db-instance --db-instance-identifier mydb --force-failover

Answer

aws rds create-db-instance --db-instance-identifier mydb --multi-az

Answer

aws rds create-db-cluster --db-instance-identifier mydb --multi-az

Question 4

A company runs an e-commerce platform using Amazon DynamoDB as the database. The table has a provisioned capacity of 5000 WCU and 3000 RCU. During a flash sale, the write traffic spikes to 8000 WCU for 10 minutes, causing significant throttling. The operations team notices that the table's WriteCapacityUnits metric shows 5000, but the ConsumedWriteCapacityUnits metric peaks at 4500. The application is experiencing errors and slow response times. The team wants to handle such spikes automatically without manual intervention and without over-provisioning. Which solution should be implemented?

Accepted Answer

Enable DynamoDB Auto Scaling with a target utilization of 70% and a minimum capacity of 5000 WCU. Option A is correct because DynamoDB Auto Scaling can adjust capacity based on demand, and setting a target utilization of 70% allows headroom for spikes. Option B is wrong because on-demand capacity is simpler but can be more expensive for predictable workloads. Option C is wrong because increasing WCU to 8000 permanently would be costly. Option D is wrong because SQS adds latency and does not solve the throttling issue in real-time.

Answer

Increase the provisioned WCU to 8000 permanently

Answer

Implement an Amazon SQS queue to buffer write requests and process them asynchronously

Answer

Switch the table to on-demand capacity mode

Question 5

An e-learning platform uses Amazon Aurora MySQL for its database. The application runs reporting queries that scan large portions of the database, causing high CPU utilization on the primary instance. The primary instance is a db.r5.2xlarge with 64 GB memory. The reporting queries are not time-sensitive but need to return results within 5 minutes. The operations team wants to reduce the impact on the primary instance without increasing costs significantly. Which action should be taken?

Accepted Answer

Create an Aurora Replica and configure the reporting application to connect to the replica endpoint. Option D is correct because creating an Aurora Replica and directing reporting traffic to it offloads the primary instance. Option A is wrong because increasing the instance class is costly and may not be needed. Option B is wrong because ElastiCache is for caching, not for heavy reporting queries. Option C is wrong because the parameter group change would affect all queries, not just reporting.

Answer

Modify the DB cluster parameter group to enable result set caching

Answer

Use Amazon ElastiCache to cache the reporting results

Answer

Increase the primary instance to db.r5.4xlarge

Question 6

A company uses Amazon RDS for PostgreSQL with a single-AZ deployment. The operations team needs to ensure that the database is available during a planned maintenance event that requires a reboot. The maintenance window is set for 30 minutes. The database size is 200 GB and the application can tolerate a few minutes of downtime. Which action should the team take to minimize downtime during the reboot?

Accepted Answer

Modify the DB instance to be Multi-AZ. Option C is correct because enabling Multi-AZ allows a failover to the standby with minimal downtime during maintenance. Option A is wrong because a manually created snapshot does not reduce downtime during a reboot. Option B is wrong because read replicas do not automatically take over on reboot. Option D is wrong because a DB instance restart still requires the instance to be unavailable during reboot.

Answer

Take a manual snapshot before the maintenance window and restore it if needed

Answer

Create a read replica and promote it to primary after the reboot

Answer

Schedule the reboot during a low-traffic period

Question 7

A company is running an Amazon RDS for MySQL Multi-AZ DB instance. The application experiences a brief write disruption during automatic failover. The database workload has low write latency requirements. Which configuration change would minimize application impact during failover?

Accepted Answer

Change the DB instance to use a Multi-AZ DB cluster configuration.. Using a read replica for failover is not supported in RDS MySQL; Multi-AZ is the correct approach. Option D (Multi-AZ cluster) provides faster failover than Multi-AZ with a standby. Option A is correct because RDS Multi-AZ cluster uses a writer and two reader instances, reducing failover time. Option B is not supported. Option C increases cost without performance benefit.

Answer

Create a read replica in a different Availability Zone and promote it during failover.

Answer

Use a single-AZ deployment and rely on automated backups for recovery.

Answer

Increase the DB instance class to reduce failover time.

Question 8

A company uses Amazon DynamoDB with On-Demand capacity for a gaming application. During a new game launch, write traffic spikes 10x normal for 30 minutes. Some write requests receive ProvisionedThroughputExceeded exceptions. What is the MOST likely cause and solution?

Accepted Answer

The partition key is not distributing writes evenly, causing a hot partition. Redesign the partition key for uniform access.. On-Demand capacity can handle spikes but has per-partition throughput limits. If a hot partition exists, writes to that partition may exceed its limit. Option A is correct because uneven partition keys cause throttling. Option B is incorrect because On-Demand does not have table-level limits. Option C is not the primary cause. Option D is incorrect as GSI writes also consume write capacity.

Answer

On-Demand capacity cannot handle sudden spikes. Switch to Provisioned capacity with auto scaling.

Answer

DynamoDB Streams is enabled, causing additional write throttling. Disable streams.

Answer

The table has a global secondary index with a different partition key that is unevenly accessed. Remove the GSI.

Question 9

A database administrator needs to monitor Amazon RDS for PostgreSQL connections and terminate idle connections that have been open for more than 1 hour. Which combination of steps should be taken?

Accepted Answer

Enable audit logging and stream to Amazon CloudWatch Logs. Create a metric filter for connection events. Use CloudWatch Alarm to trigger a Lambda function that runs a SQL query to terminate idle connections.. CloudWatch Logs capture connection logs. Lambda can query the database to terminate idle connections. Option A is correct. Option B uses EC2 which is less automated. Option C uses RDS Event Notifications which do not include connection details. Option D lacks Lambda automation.

Answer

Use Amazon RDS Performance Insights to view active connections and manually terminate idle connections via the AWS Management Console.

Answer

Configure an RDS event subscription for 'connection' events and send to Amazon SNS. Use SNS to notify an EC2 instance that runs a script to terminate idle connections.

Answer

Enable RDS Enhanced Monitoring and configure a CloudWatch alarm to invoke an AWS Lambda function that terminates idle connections.

Question 10

A company runs an Amazon Aurora MySQL database with read replicas to handle read traffic. During a recent load test, the primary instance CPU utilization reached 90%, but read replicas remained below 50%. The application uses a custom ORM that connects to a single endpoint. Which change will best distribute read traffic?

Accepted Answer

Configure the application to use the Aurora reader endpoint for read queries.. Aurora read replicas are accessed through the reader endpoint, not the cluster endpoint. Option A is correct. Option B is wrong because read replicas use reader endpoint. Option C is not a feature of Aurora. Option D is incorrect because ProxySQL is not needed.

Answer

Use Amazon RDS Proxy with read/write splitting.

Answer

Place the read replicas behind an Application Load Balancer.

Answer

Enable Aurora Auto Scaling for replicas and use the cluster endpoint for both read and write.

Question 11

A company is migrating an on-premises Oracle database to Amazon RDS for Oracle using AWS DMS. The source database is 2 TB and has high transaction volume. The migration needs minimal downtime. Currently, full load completes but CDC task fails with 'ORA-1555: snapshot too old' errors. What should the DBA do to resolve this?

Accepted Answer

Increase the undo retention period and undo tablespace size on the source Oracle database.. Snapshot too old error occurs when undo data is overwritten. Increasing undo retention and tablespace size allows DMS to read consistent data. Option A is correct. Option B reduces performance. Option C increases log volume. Option D may cause data loss.

Answer

Restart the migration with a new full load and use a smaller task.

Answer

Enable supplemental logging on the source and use a larger DMS instance.

Answer

Reduce the transaction volume by pausing non-essential transactions during CDC.

Question 12

A company uses Amazon DynamoDB with auto scaling enabled. During a flash sale, write traffic spikes and some requests receive ThrottlingException errors. The table's write capacity auto scaling reaches the maximum configured capacity but still throttles. Which TWO actions should resolve the throttling? (Choose TWO.)

Accepted Answer

Increase the maximum write capacity setting for the auto scaling policy.. Option A increases maximum capacity to allow auto scaling to scale higher. Option C improves partition key distribution to avoid hot partitions. Option B does not help because auto scaling already reached max. Option D is not a DynamoDB feature. Option E is irrelevant.

Answer

Add a DynamoDB Accelerator (DAX) cluster to cache writes.

Answer

Enable DynamoDB Streams to offload write traffic.

Answer

Disable auto scaling and use On-Demand capacity mode.

Question 13

A company runs an Amazon RDS for SQL Server database. The database size is 500 GB. The company needs to create a test environment with a copy of the production database that refreshes daily. Which THREE steps should be taken to automate this? (Choose THREE.)

Accepted Answer

Use AWS Backup or AWS Lambda to take a manual snapshot of the production DB instance daily.. Option A creates a snapshot, Option B restores to a new instance, Option D updates the application endpoint. Option C is unnecessary because restoring from snapshot does not require backup. Option E is not needed as snapshot already provides point-in-time.

Answer

Create a read replica of the production instance and promote it to the test environment.

Answer

Enable automated backups on the test instance after restoration.

Question 14

A company is designing a disaster recovery strategy for an Amazon Aurora MySQL database with a recovery point objective (RPO) of 1 second and a recovery time objective (RTO) of 1 minute. Which TWO solutions meet these requirements? (Choose TWO.)

Accepted Answer

Deploy an Aurora Global Database with a secondary region.. Option A: Aurora Global Database provides replication across regions with RPO of seconds and RTO of minutes. Option D: Cross-Region read replicas can be promoted quickly. Option B: Multi-AZ is within region, not cross-region DR. Option C: Automated backups have RPO of 5 minutes. Option E: Snapshots are not frequent enough.

Answer

Use a Multi-AZ DB cluster deployment.

Answer

Take manual snapshots every hour and copy to another region.

Answer

Enable automated backups and perform point-in-time recovery in another region.

Question 15

A financial services company runs a production Amazon Aurora MySQL database cluster (1 writer, 2 readers) in us-east-1. The database stores critical trading data. The company's disaster recovery policy requires an RPO of 5 seconds and an RTO of 1 minute for a regional failure. The current setup does not include any cross-region replication. The database is 5 TB in size. The operations team needs to implement a solution that meets the DR requirements with minimal cost and operational overhead. Which solution should the team implement?

Accepted Answer

Deploy an Aurora Global Database with a secondary cluster in us-west-2. Configure the secondary cluster as a failover target.. Aurora Global Database provides replication across regions with typical RPO of seconds and RTO of minutes. It is the most appropriate solution for low RPO/RTO with minimal overhead. Option B is correct. Option A (cross-region read replicas) can have replication lag exceeding 5 seconds. Option C (automated backups) have RPO of 5 minutes. Option D (DMS) adds cost and complexity.

Answer

Enable automated backups and configure cross-Region snapshot copy. Use point-in-time recovery in the secondary region.

Answer

Use AWS Database Migration Service (DMS) to continuously replicate changes to an Aurora cluster in us-west-2.

Answer

Create cross-Region read replicas in us-west-2 and set up a replication channel. In disaster, promote a replica.

DBS-C01 Management and Operations Practice Test 20 — 15 Questions

Exhibit

DBS-C01 Management and Operations Practice Test 20 — 15 Questions

Exhibit