Database Specialty

A company is building a software as a service application.As part of the new user sign-on workflow, a Python script invokes the CreateTable operation using theAmazon DynamoDB API.After the call returns, the script attempts to call PutItem.Occasionally, the PutItem request fails with a ResourceNotFoundException error, which causes the workflow to fail.The development team has confirmed that the same table name is used in the two API calls.How should a database specialist fix this issue?Read More →

A company has an application that uses an Amazon DynamoDB table to store user data.Every morning, a single-threaded process calls the DynamoDB API Scan operation to scan the entire table and generate a critical start-of-day report for management.A successful marketing campaign recently doubled the number of items in the table, and now the process takes too long to run and the report is not generated in time.A database specialist needs to improve the performance of the process.The database specialist notes that, when the process is running, 15% of the table’s provisioned read capacity units (RCUs) are being used.What should the database specialist do?Read More →

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?Read More →

A company has an Amazon RDS Multi-AZ DB instances that is 200 GB in size with an RPO of 6 hours.To meet the company’s disaster recovery policies, the database backup needs to be copied into another Region.The company requires the solution to be cost-effective and operationally efficient.What should a Database Specialist do to copy the database backup into a different Region?Read More →

An online gaming company is planning to launch a new game with Amazon DynamoDB as its data store.The database should be designated to support the following use cases:✑ Update scores in real time whenever a player is playing the game.✑ Retrieve a player’s score details for a specific game session.A Database Specialist decides to implement a DynamoDB table.Each player has a unique user_id and each game has a unique game_id.Which choice of keys is recommended for the DynamoDB table?Read More →

A large company is using an Amazon RDS for Oracle Multi-AZ DB instance with a Java application.As a part of its disaster recovery annual testing, the company would like to simulate an Availability Zone failure and record how the application reacts during the DB instance failover activity.The company does not want to make any code changes for this activity.What should the company do to achieve this in the shortest amount of time?Read More →

A company has a production Amazon Aurora Db cluster that serves both online transaction processing (OLTP) transactions and compute-intensive reports.The reports run for 10% of the total cluster uptime while the OLTP transactions run all the time.The company has benchmarked its workload and determined that a six- node Aurora DB cluster is appropriate for the peak workload.The company is now looking at cutting costs for this DB cluster, but needs to have a sufficient number of nodes in the cluster to support the workload at different times.The workload has not changed since the previous benchmarking exercise.How can a Database Specialist address these requirements with minimal user involvement?Read More →

A startup company in the travel industry wants to create an application that includes a personal travel assistant to display information for nearby airports based on user location.The application will use Amazon DynamoDB and must be able to access and display attributes such as airline names, arrival times, and flight numbers.However, the application must not be able to access or display pilot names or passenger counts.Which solution will meet these requirements MOST cost-effectively?Read More →

A company is running its customer feedback application on Amazon Aurora MySQL.The company runs a report every day to extract customer feedback, and a team reads the feedback to determine if the customer comments are positive or negative.It sometimes takes days before the company can contact unhappy customers and take corrective measures.The company wants to use machine learning to automate this workflow.Which solution meets this requirement with the LEAST amount of effort?Read More →

A finance company needs to make sure that its MySQL database backups are available for the most recent 90 days.All of the MySQL databases are hosted onAmazon RDS for MySQL DB instances.A database specialist must implement a solution that meets the backup retention requirement with the least possible development effort.Which approach should the database specialist take?Read More →