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.

Question 3True or False: Amazon Relational Database Service (Amazon RDS) is more suitable for databases that handle structured or relational data, where users can count with features like auto-increment and table joins. Amazon DynamoDB is more suitable for NoSQL database workloads, where tables are collection of items that have their own attributes.1 pointTrueFalse

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.

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

Which of the following is/are correct?试题 4选择一项或多项：a.Google's Bigtable cannot manage versioned data. b.Dynamo uses consistent hashing to achieve incremental scalability.c.In Google's Bigtable, the row range for a (big) table is dynamically partitioned according to the lexicographic order of row keys.  d.Google's Bigtable cannot be used with MapReduce for running large-scale parallel computations.

Which of the following is/are correct?试题 6选择一项或多项：a.Dynamo doesn’t require a rigid schema before inserting data.b.MongoDB supports the concepts of primary key and foreign key.c.Google's Bigtable does not support schema.d.The concept of schema in MongoDB is flexible, which allows programmers to modify data structure at runtime.