DataStax Cassandra Developer Certification Certification Questions and Answer (Dumps and Practice Questions)

Question : Let's say we want to implement the following schema:

Enity: Staff Member (id , name)
Enity: Permanent (specialises Staff Member) (next_appraisal_date )
Enity: Temporary (specialises Staff Member) (contract_end_date)

a Staff Member is either a Permanent employee or a Temporary contractor. How do you define disjoint in parent child
relationship?

1. An entity can only participate in only one subtype role

2. An entity cannot participate in the parent type role

3. Access Mostly Uused Products by 50000+ Subscribers

4. An entity is not complete


Correct Answer : Get Lastest Questions and Answer :
Explanation: It means Temporary employee cannot be part of permanent employee. An entity can only participate in
only one subtype role




Question : The complete flow of a video website is below

1. login to site
2. It will show all recent video channels updated
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This flow is known as

1. Logical Diagram

2. Application Workflow

3. Access Mostly Uused Products by 50000+ Subscribers

4. Login flow


Correct Answer : Get Lastest Questions and Answer :
Explanation: : all the steps you followed to browse an application is known as application workflow.




Question : What is an application workflow?

1. All the tasks in an application formed by casual dependencies

2. It is an alternate to ER diagram

3. Access Mostly Uused Products by 50000+ Subscribers

4. It is an alternate to DFD


Correct Answer : Get Lastest Questions and Answer :
Explanation: all the steps you followed to browse an application is known as application workflow and these all
steps can be have dependencies.

Related Questions

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Question : You have setup of virtual node (vnode) to avoid HotSpot issue in Cassandra cluster, what will be the correct in
this case

A. You donat need to add new node in the cluster
B. As soon as you add new node in cluster, it's going to be able to take ranges of data from every node
C. It will re-partition all the data after adding new node
D. You can assign token more efficiently to each node in cluster


1. A,B
2. B,C
3. C,D
4. A,D
5. B,D


Question : You do configuration in Cassandra.yaml file to setup number of tokens in your cluster.

1. True
2. False


Question : You already have an existing Cassandra cluster setup, having single token node setup. How, would you convert this
setup to vnode setup?


1. It cannot be done, you have to create new Cluster altogether

2. you can configure another datacenter configured with vnodes already enabled and let Cassandra automatic
mechanisms distribute the existing data into the new nodes.

3. you can configure another Cassandra cluster configured with vnodes already enabled and let Cassandra
automatic mechanisms distribute the existing data into the new Cluster.

4. 2 and 3


Question : Vnodes helps Cassandra in which of the following way

A. Tokens are automatically calculated and assigned to each node
B. Rebalancing a cluster is automatically accomplished when adding or removing nodes.
C. Rebuilding a dead node is faster because it involves every other node in the cluster.
D. The proportion of vnodes assigned to each machine in a cluster can be assigned, so smaller and larger computers can be used
in building a cluster


1. A,B,C
2. B,C,D
3. A,B,D
4. A,C,D
5. A,B,C,D


Question : If not using virtual nodes (vnodes), you must calculate tokens for your cluster.

1. True
2. False


Question : Which all is correct, with regards to Gossip protocol?

A. Gossip is a peer-to-peer communication protocol in which nodes periodically exchange state information about themselves and
about other nodes they know about.
B. The gossip process runs every second and exchanges state messages with up to three other nodes in the cluster.
C. A gossip message has a version associated with it, so that during a gossip exchange, older information is overwritten with
the most current state for a particular node.
D. Every node in the Cluster should work as a seed node


1. A,B,C
2. B,C,D
3. A,C,D
4. A,B,D