Free DBS-C01 Exam Braindumps

A large retail company recently migrated its three-tier ecommerce applications to AWS. The company’s backend database is hosted on Amazon Aurora PostgreSQL. During peak times, users complain about longer page load times. A database specialist reviewed Amazon RDS Performance Insights and found a spike in IO:XactSync wait events. The SQL attached to the wait events are all single INSERT statements.
How should this issue be resolved?

1. A. Modify the application to commit transactions in batches
2. B. Add a new Aurora Replica to the Aurora DB cluster.
3. C. Add an Amazon ElastiCache for Redis cluster and change the application to write through.
4. D. Change the Aurora DB cluster storage to Provisioned IOPS (PIOPS).

Correct Answer: A
https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraPostgreSQL.Reference.html "This wait most often arises when there is a very high rate of commit activity on the system. You can
sometimes alleviate this wait by modifying applications to commit transactions in batches. " https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/apg-waits.xactsync.html

A large financial services company requires that all data be encrypted in transit. A Developer is attempting to connect to an Amazon RDS DB instance using the company VPC for the first time with credentials provided by a Database Specialist. Other members of the Development team can connect, but this user is consistently receiving an error indicating a communications link failure. The Developer asked the Database Specialist to reset the password a number of times, but the error persists.
Which step should be taken to troubleshoot this issue?

1. A. Ensure that the database option group for the RDS DB instance allows ingress from the Developer machine’s IP address
2. B. Ensure that the RDS DB instance’s subnet group includes a public subnet to allow the Developer to connect
3. C. Ensure that the RDS DB instance has not reached its maximum connections limit
4. D. Ensure that the connection is using SSL and is addressing the port where the RDS DB instance is listening for encrypted connections

Correct Answer: D
https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/SQLServer.Concepts.General.SSL.Using.html

A company is using Amazon with Aurora Replicas for read-only workload scaling. A Database Specialist needs to split up two read-only applications so each application always connects to a dedicated replica. The Database Specialist wants to implement load balancing and high availability for the read-only applications.
Which solution meets these requirements?

1. A. Use a specific instance endpoint for each replica and add the instance endpoint to each read-only application connection string.
2. B. Use reader endpoints for both the read-only workload applications.
3. C. Use a reader endpoint for one read-only application and use an instance endpoint for the other read-only application.
4. D. Use custom endpoints for the two read-only applications.

Correct Answer: D
https://aws.amazon.com/about-aws/whats-new/2018/11/amazon-aurora-simplifies-workload-management-with-c

An online gaming company is using an Amazon DynamoDB table in on-demand mode to store game scores. After an intensive advertisement campaign in South America, the average number of concurrent users rapidly increases from 100,000 to 500,000 in less than 10 minutes every day around 5 PM.
The on-call software reliability engineer has observed that the application logs contain a high number of DynamoDB throttling exceptions caused by game score insertions around 5 PM. Customer service has also reported that several users are complaining about their scores not being registered.
How should the database administrator remediate this issue at the lowest cost?

1. A. Enable auto scaling and set the target usage rate to 90%.
2. B. Switch the table to provisioned mode and enable auto scaling.
3. C. Switch the table to provisioned mode and set the throughput to the peak value.
4. D. Create a DynamoDB Accelerator cluster and use it to access the DynamoDB table.

Correct Answer: B

An Amazon RDS EBS-optimized instance with Provisioned IOPS (PIOPS) storage is using less than half of its allocated IOPS over the course of several hours under constant load. The RDS instance exhibits multi-second read and write latency, and uses all of its maximum bandwidth for read throughput, yet the instance uses less than half of its CPU and RAM resources.
What should a Database Specialist do in this situation to increase performance and return latency to sub- second levels?

1. A. Increase the size of the DB instance storage
2. B. Change the underlying EBS storage type to General Purpose SSD (gp2)
3. C. Disable EBS optimization on the DB instance
4. D. Change the DB instance to an instance class with a higher maximum bandwidth

Correct Answer: D
https://docs.amazonaws.cn/en_us/AmazonRDS/latest/UserGuide/CHAP_BestPractices.html