To achieve high availability and durability, Dynamo replicates its data on multiple machines.b.Dynamo runs on a commodity hardware infrastructure, i.e., a cluster of commodity machines that share disk and memory.c.Dynamo provides simple read and write operations to a data item that can be uniquely identified by a key.d.Dynamo uses the "shared everything" architecture, and can scale out to improve performance.

Dynamo is a NoSQL database developed by Amazon. Which of the following about Dynamo is/are correct?试题 8选择一项或多项：a.Dynamo is targeted mainly at applications where no updates are rejected due to concurrent writes.b.Dynamo uses the technique of consistent hashing to map each node to a single datacenter.c.Dynamo is designed to achieve strong consistency and high data availability simultaneously.d.Dynamo provides security related support for managing data, such as authentication and authorization.

Does Dynamo DB sacrifice Consistency for Scalability and Latency?If yes, which design element or service level agreement specifies this? If no, how this couldbe achieved?

To reduce costs, a company is planning to migrate a NoSQL database to AWS. Which AWS service is fully managed and can automatically scale throughput capacity to meet database workload demands?a.Amazon DynamoDBb.Amazon Redshiftc.Amazon Aurorad.Amazon RDS

Question 4Amazon DynamoDB is designed for scale and performance. In most cases, the DynamoDB response times can be measured in single-digit milliseconds. However, there are certain use cases that require response times in microseconds. For these use cases, DynamoDB Accelerator (DAX) delivers fast response times for accessing eventually consistent data. Which statements about DAX are correct? (Choose THREE.)1 pointDAX reduces operational and application complexity by providing a managed service that is compatible with the DynamoDB API.Although using DAX has a cost, it can reduce the consumption of DynamoDB table capacity. If the data is read intensive (that is, millions of requests per second), DAX can result in cost savings by caching the data while also providing better read latency, being beneficial for scenarios in need of repeated reads for individual keys.DAX does not support server-side encryption (SSE).DAX is not designed for applications that are write-intensive. It can also add cost to applications that do not perform much read activity.DAX does not support encrypting data in transit, which means that communication between an application and DAX cannot be encrypted.

Key – value based database (DynamoDB)