Which of the following is/are a key-value data store?试题 14选择一项或多项：a.CouchDBb.Hbasec.Voldemortd.Hypertablee.Dynamof.MongoDB

Key – value based database (DynamoDB)

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.

MongoDB is a _________ database that provides high performance, high availability, and easy scalability.(1 Point)All of the abovedocumentgraphkey value

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

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.