Amazon DBS-C01 Online Practice Questions and Exam Preparation

Amazon DBS-C01 Online Questions & Answers

• Question 261:

  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?

  A. Enable Amazon DynamoDB Streams on the table. Create an AWS Lambda function triggered by the stream. Write the log entries to an Amazon S3 object.
  B. Create 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.
  C. Enable 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.
  D. Enable 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.
  D. Enable 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.

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  Explanation/Reference:

• Question 262:

  A company wants to build a new invoicing service for its cloud-native application on AWS. The company has a small development team and wants to focus on service feature development and minimize operations and maintenance as much as possible. The company expects the service to handle billions of requests and millions of new records every day. The service feature requirements, including data access patterns are well- defined. The service has an availability target of 99.99% with a milliseconds latency requirement. The database for the service will be the system of record for invoicing data.

  Which database solution meets these requirements at the LOWEST cost?

  A. Amazon Neptune
  B. Amazon Aurora PostgreSQL Serverless
  C. Amazon RDS for PostgreSQL
  D. Amazon DynamoDB
  D. Amazon DynamoDB

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  Explanation/Reference:

  Known patterns, minimum maintenance, miliseconds latency

• Question 263:

  A company has deployed an e-commerce web application in a new AWS account. An Amazon RDS for MySQL Multi-AZ DB instance is part of this deployment with a database- 1.xxxxxxxxxxxx.us-east- 1.rds.amazonaws.com endpoint listening on port 3306. The company's Database Specialist is able to log in to MySQL and run queries from the bastion host using these details.

  When users try to utilize the application hosted in the AWS account, they are presented with a generic error message. The application servers are logging a "could not connect to server: Connection times out" error message to Amazon CloudWatch Logs.

  What is the cause of this error?

  A. The user name and password the application is using are incorrect.
  B. The security group assigned to the application servers does not have the necessary rules to allow inbound connections from the DB instance.
  C. The security group assigned to the DB instance does not have the necessary rules to allow inbound connections from the application servers.
  D. The user name and password are correct, but the user is not authorized to use the DB instance.
  C. The security group assigned to the DB instance does not have the necessary rules to allow inbound connections from the application servers.

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  Explanation/Reference:

  Reference: https://forums.aws.amazon.com/thread.jspa?threadID=129700

• Question 264:

  A financial services organization employs an Amazon Aurora PostgreSQL DB cluster to host an application on AWS. No log files detailing database administrator activity were discovered during a recent examination. A database professional must suggest a solution that enables access to the database and maintains activity logs. The solution should be simple to implement and have a negligible effect on performance.

  Which database specialist solution should be recommended?

  A. Enable Aurora Database Activity Streams on the database in synchronous mode. Connect the Amazon Kinesis data stream to Kinesis Data Firehose. Set the Kinesis Data Firehose destination to an Amazon S3 bucket.
  B. Create an AWS CloudTrail trail in the Region where the database runs. Associate the database activity logs with the trail.
  C. Enable Aurora Database Activity Streams on the database in asynchronous mode. Connect the Amazon Kinesis data stream to Kinesis Data Firehose. Set the Firehose destination to an Amazon S3 bucket.
  D. Allow connections to the DB cluster through a bastion host only. Restrict database access to the bastion host and application servers. Push the bastion host logs to Amazon CloudWatch Logs using the CloudWatch Logs agent.
  C. Enable Aurora Database Activity Streams on the database in asynchronous mode. Connect the Amazon Kinesis data stream to Kinesis Data Firehose. Set the Firehose destination to an Amazon S3 bucket.

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  Explanation/Reference:

  https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/DBActivityStreams.Ov erview.html

• Question 265:

  A vehicle insurance company needs to choose a highly available database to track vehicle owners and their insurance details. The persisted data should be immutable in the database, including the complete and sequenced history of changes over time with all the owners and insurance transfer details for a vehicle.

  The data should be easily verifiable for the data lineage of an insurance claim.

  Which approach meets these requirements with MINIMAL effort?

  A. Create a blockchain to store the insurance details. Validate the data using a hash function to verify the data lineage of an insurance claim.
  B. Create an Amazon DynamoDB table to store the insurance details. Validate the data using AWS DMS validation by moving the data to Amazon S3 to verify the data lineage of an insurance claim.
  C. Create an Amazon QLDB ledger to store the insurance details. Validate the data by choosing the ledger name in the digest request to verify the data lineage of an insurance claim.
  D. Create an Amazon Aurora database to store the insurance details. Validate the data using AWS DMS validation by moving the data to Amazon S3 to verify the data lineage of an insurance claim.
  C. Create an Amazon QLDB ledger to store the insurance details. Validate the data by choosing the ledger name in the digest request to verify the data lineage of an insurance claim.

• Question 266:

  Amazon Neptune is being used by a corporation as the graph database for one of its products. During an ETL procedure, the company's data science team produced enormous volumes of temporary data by unintentionally. The Neptune DB cluster extended its storage capacity automatically to handle the added data, but the data science team erased the superfluous data.

  What should a database professional do to prevent incurring extra expenditures for cluster volume space that is not being used?

  A. Take a snapshot of the cluster volume. Restore the snapshot in another cluster with a smaller volume size.
  B. Use the AWS CLI to turn on automatic resizing of the cluster volume.
  C. Export the cluster data into a new Neptune DB cluster.
  D. Add a Neptune read replica to the cluster. Promote this replica as a new primary DB instance. Reset the storage space of the cluster.
  C. Export the cluster data into a new Neptune DB cluster.

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  Explanation/Reference:

  The only way to shrink the storage space used by your DB cluster when you have a large amount of unused allocated space is to export all the data in your graph and then reload it into a new DB cluster. Creating and restoring a snapshot does not reduce the amount of storage allocated for your DB cluster, because a snapshot retains the original image of the cluster's underlying storage.

• Question 267:

  A corporation is transitioning from an IBM Informix database to an Amazon RDS for SQL Server Multi-AZ implementation with Always On Availability Groups (AGs). SQL Server Agent tasks are scheduled to execute at 5-minute intervals on the Always On AG listener to synchronize data between the Informix and SQL Server databases. After a successful failover to the backup node with minimum delay, users endure hours of stale data.

  How can a database professional guarantee that consumers view the most current data after a failover?

  A. Set TTL to less than 30 seconds for cached DNS values on the Always On AG listener.
  B. Break up large transactions into multiple smaller transactions that complete in less than 5 minutes.
  C. Set the databases on the secondary node to read-only mode.
  D. Create the SQL Server Agent jobs on the secondary node from a script when the secondary node takes over after a failure.
  D. Create the SQL Server Agent jobs on the secondary node from a script when the secondary node takes over after a failure.

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  Explanation/Reference:

  https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_SQLServerMultiAZ.html If you have SQL Server Agent jobs, recreate them on the secondary. You do so because these jobs are stored in the msdb database, and you can't replicate this database by using Database Mirroring (DBM) or Always On Availability Groups (AGs). Create the jobs first in the original primary, then fail over, and create the same jobs in the new primary.

• Question 268:

  A global company is creating an application. The application must be highly available. The company requires an RTO and an RPO of less than 5 minutes. The company needs a database that will provide the ability to set up an active-active configuration and near real- time synchronization of data across tables in multiple AWS Regions.

  Which solution will meet these requirements?

  A. Amazon RDS for MariaDB with cross-Region read replicas
  B. Amazon RDS With a Multi-AZ deployment
  C. Amazon DynamoDB global tables
  D. Amazon DynamoDB With a global secondary index (GSI)
  C. Amazon DynamoDB global tables

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  Explanation/Reference:

  Amazon DynamoDB global tables are a fully managed, serverless, multi-Region, and multi- active database option that delivers fast and localized read and write performance for massively scaled global applications. Global tables provide you

  99.999% availability, increased application resiliency, and improved business continuity1. As global tables replicate your Amazon DynamoDB tables automatically across your choice of AWS Regions, you can achieve fast, local read and write

  performance1. In the rare event of a single Region failure, there is no need for a database failover as global tables' multi-active architecture allows customers to read and write to any replica table1. Global tables also eliminate the difficult work

  of replicating data between Regions and resolving update conflicts for multi-active workloads1.

  Using Amazon DynamoDB global tables, the company can:

  Set up an active-active configuration and near real-time synchronization of data across tables in multiple AWS Regions.

  Meet the RTO and RPO of less than 5 minutes, as global tables provide automatic failover and zero data loss in case of a Region failure. Achieve high availability, durability, and scalability for their application.

• Question 269:

  A company is deploying a solution in Amazon Aurora by migrating from an on-premises system. The IT department has established an AWS Direct Connect link from the company's data center. The company's Database Specialist has selected the option to require SSL/TLS for connectivity to prevent plaintext data from being set over the network. The migration appears to be working successfully, and the data can be queried from a desktop machine.

  Two Data Analysts have been asked to query and validate the data in the new Aurora DB cluster. Both Analysts are unable to connect to Aurora. Their user names and passwords have been verified as valid and the Database Specialist can connect to the DB cluster using their accounts. The Database Specialist also verified that the security group configuration allows network from all corporate IP addresses.

  What should the Database Specialist do to correct the Data Analysts' inability to connect?

  A. Restart the DB cluster to apply the SSL change.
  B. Instruct the Data Analysts to download the root certificate and use the SSL certificate on the connection string to connect.
  C. Add explicit mappings between the Data Analysts' IP addresses and the instance in the security group assigned to the DB cluster.
  D. Modify the Data Analysts' local client firewall to allow network traffic to AWS.
  B. Instruct the Data Analysts to download the root certificate and use the SSL certificate on the connection string to connect.

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  Explanation/Reference:

  To connect using SSL: Provide the SSLTrust certificate (can be downloaded from AWS) ?Provide SSL options when connecting to database Not using SSL on a DB that enforces SSL would result in error https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/ssl-certificate-rotation- aurora-postgresql.html

• Question 270:

  An ecommerce company is using Amazon DynamoDB as the backend for its order- processing application. The

  steady increase in the number of orders is resulting in increased DynamoDB costs. Order verification and reporting perform many repeated GetItem functions that pull similar datasets, and this read activity is contributing to the increased costs. The company wants to control these costs without significant development efforts.

  How should a Database Specialist address these requirements?

  A. Use AWS DMS to migrate data from DynamoDB to Amazon DocumentDB
  B. Use Amazon DynamoDB Streams and Amazon Kinesis Data Firehose to push the data into Amazon Redshift
  C. Use an Amazon ElastiCache for Redis in front of DynamoDB to boost read performance
  D. Use DynamoDB Accelerator to offload the reads
  D. Use DynamoDB Accelerator to offload the reads

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  Explanation/Reference:

  https://docs.amazonaws.cn/en_us/amazondynamodb/latest/developerguide/DAX.html "Applications that are read-intensive, but are also cost-sensitive. With DynamoDB, you provision the number of reads per second that your application requires. If read activity increases, you can increase your tables' provisioned read throughput (at an additional cost). Or, you can offload the activity from your application to a DAX cluster, and reduce the number of read capacity units that you need to purchase otherwise."