Question-5: Which of the following statements are correct with regards to Cassandra Data Modeling and Architecture?
- In Cassandra for a Row primary key is optional.
- You can connect to any node in Cassandra cluster for accessing the data.
- Typically, a cluster can have only one keyspace.
- Typically, a cluster should have only one keyspace for each application.
Ans: B,D
Exp: Cassandra database is a partitioned row store, where rows are organized into tables with mandatory primary key (it is not optional). They you can connect any node in any data center and access the data using the CQL language. And usually a cluster can have one keyspace per application composed of different tables.
Client read or write request can be sent to any node in the cluster. When a client connects to a node with a request, that node serves as the coordinator node for that particular client operation. This coordinator node acts as a proxy between the client application and the nodes that own the data being requested. It is the coordinator nodes responsibility to find which nodes in the ring should get the request based on how the cluster is configured.
