DBS-C01 Question Bank · Latest 50 Questions Free Preview (Page 3/5)
Questions 21–30 of the latest 50 DBS-C01 questions (5 pages total), with answers and explanations, no login required. Practice all 376 questions online.
Question 21 · No. 347 · Single choice
An online bookstore uses Amazon Aurora MySQL as its backend database. After the online bookstore added a popular book to the online catalog, customers began reporting intermittent timeouts on the checkout page. A database specialist determined that increased load was causing locking contention on the database. The database specialist wants to automatically detect and diagnose database performance issues and to resolve bottlenecks faster. Which solution will meet these requirements?
- A. Turn on Performance Insights for the Aurora MySQL database. Configure and turn on Amazon DevOps Guru for RDS.
- B. Create a CPU usage alarm. Select the CPU utilization metric for the DB instance. Create an Amazon Simple Notification Service (Amazon SNS) topic to notify the database specialist when CPU utilization is over 75%.
- C. Use the Amazon RDS query editor to get the process ID of the query that is causing the database to lock. Run a command to end the process.
- D. Use the SELECT INTO OUTFILE S3 statement to query data from the database. Save the data directly to an Amazon S3 bucket. Use Amazon Athena to analyze the files for long-running queries.
Answer: A
Explanation: The solution that will meet the requirements is to turn on Performance Insights for the Aurora MySQL database and configure and turn on Amazon DevOps Guru for RDS. This will allow the database specialist to automatically detect and diagnose database performance issues and resolve bottlenecks faster.
Question 22 · No. 348 · Single choice
A company runs an ecommerce application on premises on Microsoft SQL Server. The company is planning to migrate the application to the AWS Cloud. The application code contains complex T-SQL queries and stored procedures. The company wants to minimize database server maintenance and operating costs after the migration is completed. The company also wants to minimize the need to rewrite code as part of the migration effort. Which solution will meet these requirements?
- A. Migrate the database to Amazon Aurora PostgreSQL. Turn on Babelfish.
- B. Migrate the database to Amazon S3. Use Amazon Redshift Spectrum for query processing.
- C. Migrate the database to Amazon RDS for SQL Server. Turn on Kerberos authentication.
- D. Migrate the database to an Amazon EMR cluster that includes multiple primary nodes.
Answer: A
Explanation: Migrating the database to Amazon Aurora PostgreSQL and turning on Babelfish will meet the requirements of minimizing database server maintenance and operating costs, as well as minimizing the need to rewrite code. Aurora PostgreSQL is compatible with Microsoft SQL Server, allowing the complex T-SQL queries and stored procedures to be executed without code changes.
Question 23 · No. 349 · Single choice
A coffee machine manufacturer is equipping all of its coffee machines with IoT sensors. The IoT core application is writing measurements for each record to Amazon Timestream. The records have multiple dimensions and measures. The measures include multiple measure names and values. An analysis application is running queries against the Timestream database and is focusing on data from the current week. A database specialist needs to optimize the query costs of the analysis application. Which solution will meet these requirements?
- A. Ensure that queries contain whole records over the relevant time range.
- B. Use time range, measure name, and dimensions in the WHERE clause of the query.
- C. Avoid canceling any query after the query starts running.
- D. Implement exponential backoff in the application.
Answer: B
Explanation: Using time range, measure name, and dimensions in the WHERE clause of the query allows the analysis application to filter and narrow down the data being queried, reducing the query costs.
Question 24 · No. 350 · Single choice
A gaming company is building a mobile game that will have as many as 25,000 active concurrent users in the first 2 weeks after launch. The game has a leaderboard that shows the 10 highest scoring players over the last 24 hours. The leaderboard calculations are processed by an AWS Lambda function, which takes about 10 seconds. The company wants the data on the leaderboard to be no more than 1 minute old. Which architecture will meet these requirements in the MOST operationally efficient way?
- A. Deliver the player data to an Amazon Timestream database. Create an Amazon ElastiCache for Redis cluster. Configure the Lambda function to store the results in Redis. Create a scheduled event with Amazon EventBridge to invoke the Lambda function once every minute. Reconfigure the game server to query the Redis cluster for the leaderboard data.
- B. Deliver the player data to an Amazon Timestream database. Create an Amazon DynamoDB table. Configure the Lambda function to store the results in DynamoDCreate a scheduled event with Amazon EventBridge to invoke the Lambda function once every minute. Reconfigure the game server to query the DynamoDB table for the leaderboard data.
- C. Deliver the player data to an Amazon Aurora MySQL database. Create an Amazon DynamoDB table. Configure the Lambda function to store the results in MySQL. Create a scheduled event with Amazon EventBridge to invoke the Lambda function once every minute. Reconfigure the game server to query the DynamoDB table for the leaderboard data.
- D. Deliver the player data to an Amazon Neptune database. Create an Amazon ElastiCache for Redis cluster. Configure the Lambda function to store the results in Redis. Create a scheduled event with Amazon EventBridge to invoke the Lambda function once every minute. Reconfigure the game server to query the Redis cluster for the leaderboard data.
Answer: B
Explanation: I chose option B because delivering the player data to an Amazon Timestream database and storing the results in an Amazon DynamoDB table will provide a scalable and efficient solution. DynamoDB is a highly available and durable NoSQL database that can handle large volumes of read and write requests. By creating a scheduled event with Amazon EventBridge to invoke the Lambda function every minute, the leaderboard data will be updated frequently. The game server can then query the DynamoDB table to retrieve the leaderboard data efficiently.
Question 25 · No. 351 · Single choice
A news portal is looking for a data store to store 120 GB of metadata about its posts and comments. The posts and comments are not frequently looked up or updated. However, occasional lookups are expected to be served with single-digit millisecond latency on average. What is the MOST cost-effective solution?
- A. Use Amazon DynamoDB with on-demand capacity mode. Purchase reserved capacity.
- B. Use Amazon ElastiCache for Redis for data storage. Turn off cluster mode.
- C. Use Amazon S3 Standard-Infrequent Access (S3 Standard-IA) for data storage and use Amazon Athena to query the data.
- D. Use Amazon DynamoDB with on-demand capacity mode. Switch the table class to DynamoDB Standard-Infrequent Access (DynamoDB Standard-IA).
Answer: B
Explanation: I chose option B because using Amazon ElastiCache for Redis for data storage is the most cost-effective solution in this scenario. The data store needs to serve occasional lookups with single-digit millisecond latency, and ElastiCache for Redis is designed for fast in-memory data storage and retrieval. Additionally, turning off cluster mode helps reduce costs by simplifying the architecture and eliminating the need for data replication.
Question 26 · No. 352 · Single choice
A database specialist is planning to migrate a 4 TB Microsoft SQL Server DB instance from on premises to Amazon RDS for SQL Server. The database is primarily used for nightly batch processing. Which RDS storage option meets these requirements MOST cost-effectively?
- A. General Purpose SSD storage
- B. Provisioned IOPS storage
- C. Magnetic storage
- D. Throughput Optimized hard disk drives (HDD)
Answer: C
Explanation: The most cost-effective option for migrating a 4 TB database for nightly batch processing would be Magnetic storage. Magnetic storage offers the lowest cost per GB compared to General Purpose SSD storage and Provisioned IOPS storage. Since the database is primarily used for batch processing, the performance requirements are not as high, making Magnetic storage a suitable and cost-effective choice.
Question 27 · No. 353 · Single choice
A retail company uses Amazon Redshift for its 1 PB data warehouse. Several analytical workloads run on a Redshift cluster. The tables within the cluster have grown rapidly. End users are reporting poor performance of daily reports that run on the transaction fact tables. A database specialist must change the design of the tables to improve the reporting performance. All the changes must be applied dynamically. The changes must have the least possible impact on users and must optimize the overall table size. Which solution will meet these requirements?
- A. Use the STL_SCAN view to understand how the tables are getting scanned. Identify the columns that are used in filter and group by conditions. Create a temporary table with the identified columns as sort keys and compression as Zstandard (ZSTD) by copying the data from the original table. Drop the original table. Give the temporary table the same name that the original table had.
- B. Run an explain plan to analyze the queries on the tables. Consider recommendations from Amazon Redshift Advisor. Identify the columns that are used in filter and group by conditions. Convert the recommended columns from Redshift Advisor into sort keys with compression encoding set to RAW. Set the rest of the column compression encoding to AZ64.
- C. Run an explain plan to analyze the queries on the tables. Consider recommendations from Amazon Redshift Advisor. Identify the columns that are used in filter and group by conditions. Convert the recommended columns from Redshift Advisor into sort keys with compression encoding set to LZO. Set the rest of the column compression encoding to Zstandard (ZSTD).
- D. Run an explain plan to analyze the queries on the tables. Consider recommendations from Amazon Redshift Advisor. Identify the columns that are used in filter and group by conditions. Create a deep copy of the table with the identified columns as sort keys and compression for all columns as Zstandard (ZSTD) by using a bulk insert. Drop the original table. Give the copy table the same name that the original table had.
Answer: B
Explanation: I chose option B because it recommends running an explain plan to analyze the queries on the tables and consider recommendations from Amazon Redshift Advisor. This approach ensures that the changes made to the table design are based on accurate analysis and expert suggestions, optimizing the overall performance. Additionally, converting the recommended columns into sort keys with compression encoding set to RAW, and setting the rest of the column compression encoding to AZ64 helps in further optimizing the table size.
Question 28 · No. 354 · Single choice
A company needs to deploy an Amazon Aurora PostgreSQL DB instance into multiple accounts. The company will initiate each DB instance from an existing Aurora PostgreSQL DB instance that runs in a shared account. The company wants the process to be repeatable in case the company adds additional accounts in the future. The company also wants to be able to verify if manual changes have been made to the DB instance configurations after the company deploys the DB instances. A database specialist has determined that the company needs to create an AWS CloudFormation template with the necessary configuration to create a DB instance in an account by using a snapshot of the existing DB instance to initialize the DB instance. The company will also use the CloudFormation template's parameters to provide key values for the DB instance creation (account ID, etc.). Which final step will meet these requirements in the MOST operationally efficient way?
- A. Create a bash script to compare the configuration to the current DB instance configuration and to report any changes.
- B. Use the CloudFormation drift detection feature to check if the DB instance configurations have changed.
- C. Set up CloudFormation to use drift detection to send notifications if the DB instance configurations have been changed.
- D. Create an AWS Lambda function to compare the configuration to the current DB instance configuration and to report any changes.
Answer: B
Explanation: The most operationally efficient way to meet the given requirements is to use the CloudFormation drift detection feature to check if the DB instance configurations have changed. This feature automatically detects any configuration changes and provides a detailed report, making it easier to identify any manual changes made to the DB instance configurations.
Question 29 · No. 355 · Single choice
A database specialist needs to move a table from a database that is running on an Amazon Aurora PostgreSQL DB cluster into a new and distinct database cluster. The new table in the new database must be updated with any changes to the original table that happen while the migration is in progress. The original table contains a column to store data as large as 2 GB in the form of large binary objects (LOBs). A few records are large in size, but most of the LOB data is smaller than 32 KB. What is the FASTEST way to replicate all the data from the original table?
- A. Use AWS Database Migration Service (AWS DMS) with ongoing replication in full LOB mode.
- B. Take a snapshot of the database. Create a new DB instance by using the snapshot.
- C. Use AWS Database Migration Service (AWS DMS) with ongoing replication in limited LOB mode.
- D. Use AWS Database Migration Service (AWS DMS) with ongoing replication in inline LOB mode.
Answer: A
Explanation: The FASTEST way to replicate all the data from the original table is to use AWS Database Migration Service (AWS DMS) with ongoing replication in full LOB mode. This ensures that all changes to the original table are replicated to the new table while the migration is in progress.
Question 30 · No. 356 · Single choice
A company has an Amazon Redshift cluster with database audit logging enabled. A security audit shows that raw SQL statements that run against the Redshift cluster are being logged to an Amazon S3 bucket. The security team requires that authentication logs are generated for use in an intrusion detection system (IDS), but the security team does not require SQL queries. What should a database specialist do to remediate this issue?
- A. Set the use_fips_ssl parameter to true in the database parameter group.
- B. Turn off the query monitoring rule in the Redshift cluster's workload management (WLM).
- C. Set the enable_user_activity_logging parameter to false in the database parameter group.
- D. Disable audit logging on the Redshift cluster.
Answer: C
Explanation: To remediate the issue of logging raw SQL statements to the Amazon S3 bucket, the database specialist should set the enable_user_activity_logging parameter to false in the database parameter group. This will disable the logging of SQL queries, which are not required by the security team.