Dynamo DB Practice Test

67. A Developer has been asked to build a real-time dashboard web application to visualize the key prefixes and storage size of objects in Amazon S3 buckets. Amazon DynamoDB will be used to store the Amazon S3 metadata. What is the optimal and MOST cost-effective design to ensure that the real-time dashboard is kept up to date with the state of the objects in the Amazon S3 buckets?. Use an Amazon CloudWatch event backed by an AWS Lambda function. Issue an Amazon S3 API call to get a list of all Amazon S3 objects and persist the metadata within DynamoDB. Have the web application poll the DynamoDB table to reflect this change. Use Amazon S3 Event Notification backed by a Lambda function to persist the metadata into DynamoDB. Have the web application poll the DynamoDB table to reflect this change. Run a cron job within an Amazon EC2 instance to list all objects within Amazon S3 and persist the metadata into DynamoDB. Have the web application poll the DynamoDB table to reflect this change. Create a new Amazon EMR cluster to get all the metadata about Amazon S3 objects; persist the metadata into DynamoDB. Have the web application poll the DynamoDB table to reflect this change.

92. (2) When using a large Scan operation in DynamoDB, what technique can be used to minimize the impact of a scan on a table's provisioned throughput?. Set a smaller page size for the scan. Use parallel scans. Define a range index on the table. Prewarm the table by updating all items.

146. A Developer must build an application that uses Amazon DynamoDB. The requirements state that items being stored in the DynamoDB table will be 7KB in size and that reads must be strongly consistent. The maximum read rate is 3 items per second, and the maximum write rate is 10 items per second. How should the Developer size the DynamoDB table to meet these requirements?. Read: 3 read capacity units Write: 70 write capacity units. Read: 6 read capacity units Write: 70 write capacity units. Read: 6 read capacity units Write: 10 write capacity units. Read: 3 read capacity units Write: 10 write capacity units.

34. A Developer is writing transactions into a DynamoDB table called "SystemUpdates" that has 5 write capacity units. Which option has the highest read throughput?. Eventually consistent reads of 5 read capacity units reading items that are 4 KB in size. Strongly consistent reads of 5 read capacity units reading items that are 4 KB in size. Eventually consistent reads of 15 read capacity units reading items that are 1 KB in size. Strongly consistent reads of 15 read capacity units reading items that are 1 KB in size.

36. During non-peak hours, a Developer wants to minimize the execution time of a full Amazon DynamoDB table scan without affecting normal workloads. The workloads average half of the strongly consistent read capacity units during non-peak hours. How would the Developer optimize this scan?. Use parallel scans while limiting the rate. Use sequential scans. Increase read capacity units during the scan operation. Change consistency to eventually consistent during the scan operation.

135. A Developer wants to find a list of items in a global secondary index from an Amazon DynamoDB table. Which DynamoDB API call can the Developer use in order to consume the LEAST number of read capacity units?. Scan operation using eventually-consistent reads. Query operation using strongly-consistent reads. Query operation using eventually-consistent reads. Scan operation using strongly-consistent reads.

108.(2) Which of the following items are required to allow an application deployed on an EC2 instance to write data to a DynamoDB table? Assume that no security Keys are allowed to be stored on the EC2 instance. (Choose two.). Create an IAM User that allows write access to the DynamoDB table. Add an IAM Role to a running EC2 instance. Add an IAM User to a running EC2 Instance. Launch an EC2 Instance with the IAM Role included in the launch configuration. Create an IAM Role that allows write access to the DynamoDB table. Launch an EC2 Instance with the IAM User included in the launch configuration.

19B. A meteorological system monitors 600 temperature gauges, obtaining temperature samples every minute and saving each sample to a DynamoDB table. Each sample involves writing 1K of data and the writes are evenly distributed over time. How much write throughput is required for the target table?. 1 write capacity unit. 10 write capacity units. 60 write capacity units. 600 write capacity units. 3600 write capacity units.

101. An application is using Amazon DynamoDB as its data store, and should be able to read 100 items per second as strongly consistent reads. Each item is 5 KB in size. To what value should the table's provisioned read throughput be set?. 50 read capacity units. 100 read capacity units. 200 read capacity units. 500 read capacity units.

156. A company uses Amazon DynamoDB for managing and tracking orders. The DynamoDB table is partitioned based on the order date. The company receives a huge increase in orders during a sales event, causing DynamoDB writes to throttle, and the consumed throughput is far below the provisioned throughput. According to AWS best practices, how can this issue be resolved with MINIMAL costs?. Create a new DynamoDB table for every order date. Increase the read and write capacity units of the DynamoDB table. Add a random number suffix to the partition key values. Add a global secondary index to the DynamoDB table.

32. (2) How is provisioned throughput affected by the chosen consistency model when reading data from a DynamoDB table?. Strongly consistent reads use the same amount of throughput as eventually consistent reads. Strongly consistent reads use more throughput than eventually consistent reads. Strongly consistent reads use less throughput than eventually consistent reads. Strongly consistent reads use variable throughput depending on read activity.

22B. Which DynamoDB limits can be raised by contacting AWS support? (Choose two.). The number of hash keys per account. The maximum storage used per account. The number of tables per account. The number of local secondary indexes per account. The number of provisioned throughput units per account.

194. An Amazon DynamoDB table uses a Global Secondary Index (GSI) to support read queries. The primary table is write-heavy, whereas the GSI is used for read operations. Looking at Amazon CloudWatch metrics, the Developer notices that write operations to the primary table are throttled frequently under heavy write activity. However, write capacity units to the primary table are available and not fully consumed. Why is the table being throttled?. The GSI write capacity units are underprovisioned. There are not enough read capacity units on the primary table. Amazon DynamoDB Streams is not enabled on the table. A large write operation is being performed against another table.

107. A company caches session information for a web application in an Amazon DynamoDB table. The company wants an automated way to delete old items from the table. What is the simplest way to do this?. Write a script that deletes old records; schedule the scripts as a cron job on an Amazon EC2 instance. Add an attribute with the expiration time; enable the Time To Live feature based on that attribute. Each day, create a new table to hold session data; delete the previous day's table. Add an attribute with the expiration time; name the attribute ItemExpiration.

105. Queries to an Amazon DynamoDB table are consuming a large amount of read capacity. The table has a significant number of large attributes. The application does not need all of the attribute data. How can DynamoDB costs be minimized while maximizing application performance?. Batch all the writes, and perform the write operations when no or few reads are being performed. Create a global secondary index with a minimum set of projected attributes. Implement exponential backoffs in the application. Load balance the reads to the table using an Application Load Balancer.