Amazon DBS-C01 Exam Practice Test Instant Access

Question 1

Amazon Aurora MySQL is being used by an ecommerce business to migrate its main application database. The firm is now doing OLTP stress testing using concurrent database connections. A database professional detected sluggish performance for several particular write operations during the first round of testing.

Examining the Amazon CloudWatch stats for the Aurora DB cluster revealed a CPU usage of 90%.

Which actions should the database professional take to determine the main cause of excessive CPU use and sluggish performance most effectively? (Select two.)

AEnable Enhanced Monitoring at less than 30 seconds of granularity to review the operating system metrics before the next round of tests.

BReview the VolumeBytesUsed metric in CloudWatch to see if there is a spike in write I/O.

CReview Amazon RDS Performance Insights to identify the top SQL statements and wait events.

DReview Amazon RDS API calls in AWS CloudTrail to identify long-running queries.

EEnable Advance Auditing to log QUERY events in Amazon CloudWatch before the next round of tests.

Answer : A, C

https://aws.amazon.com/premiumsupport/knowledge-center/rds-instance-high-cpu/

https://aws.amazon.com/premiumsupport/knowledge-center/rds-mysql-slow-query/

Question 2

A Database Specialist is setting up a new Amazon Aurora DB cluster with one primary instance and three Aurora Replicas for a highly intensive, business-critical application. The Aurora DB cluster has one medium- sized primary instance, one large-sized replica, and two medium sized replicas. The Database Specialist did not assign a promotion tier to the replicas.

In the event of a primary failure, what will occur?

AAurora will promote an Aurora Replica that is of the same size as the primary instance

BAurora will promote an arbitrary Aurora Replica

CAurora will promote the largest-sized Aurora Replica

DAurora will not promote an Aurora Replica

Answer : C

Priority: If you don't select a value, the default is tier-1. This priority determines the order in which Aurora

https://docs.amazonaws.cn/en_us/AmazonRDS/latest/AuroraUserGuide/aurora-replicas-adding.html

More than one Aurora Replica can share the same priority, resulting in promotion tiers. If two or more Aurora Replicas share the same priority, then Amazon RDS promotes the replica that is largest in size. If two or more Aurora Replicas share the same priority and size, then Amazon RDS promotes an arbitrary replica in the same promotion tier.

https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/Aurora.Managing.Backups.html#Aurora.Managing.FaultTolerance

If two or more Aurora Replicas share the same priority, then Amazon RDS promotes the replica that is largest in size. If two or more Aurora Replicas share the same priority and size, then Amazon RDS promotes an arbitrary replica in the same promotion tier. https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/Concepts.AuroraHighAvailability.html

Question 3

A significant automotive manufacturer is switching a mission-critical finance application's database to Amazon DynamoDB. According to the company's risk and compliance policy, any update to the database must be documented as a log entry for auditing purposes. Each minute, the system anticipates about 500,000 log entries. Log entries should be kept in Apache Parquet files in batches of at least 100,000 records per file.

How could a database professional approach these needs while using DynamoDB?

AEnable Amazon DynamoDB Streams on the table. Create an AWS Lambda function triggered by the stream. Write the log entries to an Amazon S3 object.

BCreate a backup plan in AWS Backup to back up the DynamoDB table once a day. Create an AWS Lambda function that restores the backup in another table and compares both tables for changes. Generate the log entries and write them to an Amazon S3 object.

CEnable AWS CloudTrail logs on the table. Create an AWS Lambda function that reads the log files once an hour and filters DynamoDB API actions. Write the filtered log files to Amazon S3.

DEnable Amazon DynamoDB Streams on the table. Create an AWS Lambda function triggered by the stream. Write the log entries to an Amazon Kinesis Data Firehose delivery stream with buffering and Amazon S3 as the destination.

Answer : D

Question 4

A company is due for renewing its database license. The company wants to migrate its 80 TB transactional database system from on-premises to the AWS Cloud. The migration should incur the least possible downtime on the downstream database applications. The company's network infrastructure has limited network bandwidth that is shared with other applications.

Which solution should a database specialist use for a timely migration?

APerform a full backup of the source database to AWS Snowball Edge appliances and ship them to be loaded to Amazon S3. Use AWS DMS to migrate change data capture (CDC) data from the source database to Amazon S3. Use a second AWS DMS task to migrate all the S3 data to the target database.

BPerform a full backup of the source database to AWS Snowball Edge appliances and ship them to be loaded to Amazon S3. Periodically perform incremental backups of the source database to be shipped in another Snowball Edge appliance to handle syncing change data capture (CDC) data from the source to the target database.

CUse AWS DMS to migrate the full load of the source database over a VPN tunnel using the internet for its primary connection. Allow AWS DMS to handle syncing change data capture (CDC) data from the source to the target database.

DUse the AWS Schema Conversion Tool (AWS SCT) to migrate the full load of the source database over a VPN tunnel using the internet for its primary connection. Allow AWS SCT to handle syncing change data capture (CDC) data from the source to the target database.

Answer : A

https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Target.S3.html Using Amazon S3 as a target for AWS Database Migration Service

Question 5

The Development team recently executed a database script containing several data definition language (DDL) and data manipulation language (DML) statements on an Amazon Aurora MySQL DB cluster. The release accidentally deleted thousands of rows from an important table and broke some application functionality. This was discovered 4 hours after the release. Upon investigation, a Database Specialist tracked the issue to a DELETE command in the script with an incorrect WHERE clause filtering the wrong set of rows.

The Aurora DB cluster has Backtrack enabled with an 8-hour backtrack window. The Database Administrator also took a manual snapshot of the DB cluster before the release started. The database needs to be returned to the correct state as quickly as possible to resume full application functionality. Data loss must be minimal. How can the Database Specialist accomplish this?

AQuickly rewind the DB cluster to a point in time before the release using Backtrack.

BPerform a point-in-time recovery (PITR) of the DB cluster to a time before the release and copy the deleted rows from the restored database to the original database.

CRestore the DB cluster using the manual backup snapshot created before the release and change the application configuration settings to point to the new DB cluster.

DCreate a clone of the DB cluster with Backtrack enabled. Rewind the cloned cluster to a point in time before the release. Copy deleted rows from the clone to the original database.

Answer : A

Question 6

A company is using a Single-AZ Amazon RDS for MySQL DB instance for development. The DB instance is experiencing slow performance when queries are executed. Amazon CloudWatch metrics indicate that the instance requires more I/O capacity.

Which actions can a database specialist perform to resolve this issue? (Choose two.)

ARestart the application tool used to execute queries.

BChange to a database instance class with higher throughput.

CConvert from Single-AZ to Multi-AZ.

DIncrease the I/O parameter in Amazon RDS Enhanced Monitoring.

EConvert from General Purpose to Provisioned IOPS (PIOPS).

Answer : B, E

https://aws.amazon.com/blogs/database/best-storage-practices-for-running-production-workloads-on-hosted-databases-with-amazon-rds-or-amazon-ec2/

'If you find the pattern of IOPS usage consistently going beyond more than 16,000, you should modify the DB instance and change the storage type from gp2 to io1.

Question 7

A company has a database monitoring solution that uses Amazon CloudWatch for its Amazon RDS for SQL Server environment. The cause of a recent spike in CPU utilization was not determined using the standard metrics that were collected. The CPU spike caused the application to perform poorly, impacting users. A Database Specialist needs to determine what caused the CPU spike.

Which combination of steps should be taken to provide more visibility into the processes and queries running during an increase in CPU load? (Choose two.)

AEnable Amazon CloudWatch Events and view the incoming T-SQL statements causing the CPU to spike.

BEnable Enhanced Monitoring metrics to view CPU utilization at the RDS SQL Server DB instance level.

CImplement a caching layer to help with repeated queries on the RDS SQL Server DB instance.

DUse Amazon QuickSight to view the SQL statement being run.

EEnable Amazon RDS Performance Insights to view the database load and filter the load by waits, SQL statements, hosts, or users.

Answer : B, E

https://aws.amazon.com/premiumsupport/knowledge-center/rds-instance-high-cpu/ 'Several factors can cause an increase in CPU utilization. For example, user-initiated heavy workloads, analytic queries, prolonged deadlocks and lock waits, multiple concurrent transactions, long-running transactions, or other processes that utilize CPU resources. First, you can identify the source of the CPU usage by: Using Enhanced Monitoring Using Performance Insights'

Amazon DBS-C01 AWS Certified Database - Specialty Exam Practice Test