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

Question : When you need to add new node to Cassandra cluster, you have to bring down Cassandra cluster?

1. True
2. False

Correct Answer : 2
Explanation: No, you donat have to bring down the cluster to add new node to the cluster. You can add new node on
live cluster.
joining a cluster : first thing it does is it gossips out to those seed nodes, in the neighborhood, to get the information.
Other nodes are going to recalculate the token ranges, and figure out where that new node is going to fit in there, and
they're going to start streaming their data down to them, so that new node will start receiving data. This will be joining,
and until it's fully joined in the system, it's not ready for read, it's still accepting data. But this is a pretty critical
part of operations when you're joining a node to the cluster, because it can do it online.





Question : When your driver uses TokenAwarePolicy



1. Co-ordinator cannot be avoided, each read and write go through co-ordinator node

2. Co-ordinator is not used, each read and write directly go to the specific node, which data belong to.

3. It eliminates a hop for your data

4. 1 and 3

5. 2 and 3

Correct Answer : 5
Explanation: TokenAwarePolicy understands the token ranges and knows which node has what and which replicas store
that data as well. Now the coordinator is not so important because we can go directly to the nodes that have the data and
bypass this coordination phase. It's just more efficient. It eliminates a hop for your data.




Question : Which of the policy rely on coordinator



1. RoundRobin

2. DCAwareRoundRobinPolicy

3. TokenAwarePolicy

4. 1 and 2
5. 1 and 3


Correct Answer : 4
Explanation: RoundRobin, which do rely on coordination, and the DCAwareRoundRobinPolicy makes sure that that data
is staying in the local data center.

Related Questions

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Question : You have defined a table name HadoopExam with three columns Course_id, Course_title and course_description.
However, you want to introduce a new column to this table named Course_price. Which of the following will help you do this?

1. ALTER

2. REPLACE

3. Access Mostly Uused Products by 50000+ Subscribers

4. Not possible



Question : Which All are the Cassandra column type?

1. LIST<>

2. SET<>

3. Access Mostly Uused Products by 50000+ Subscribers

4. DICTIONARY<>



Question : Which of the following Collection type is supported by Cassandra table definition

1. list

2. list

3. Access Mostly Uused Products by 50000+ Subscribers

4. 1 and 2
5. 1,2 and 3



Question : Which of the following collection types are not supported for creating index in Cassandra table definition


1. map

2. set

3. Access Mostly Uused Products by 50000+ Subscribers

4. 1,2 and 3

5. None of the above



Question : Which of the following is correct statement?
A. A frozen value serializes multiple components into a single value.
B. Non-frozen types allow updates to individual fields.
C. Apache Cassandra treats the value of a frozen type as a blob
D. You cannot use non-frozen collections for primary key columns.


1. A,B,C
2. B,C,D
3. Access Mostly Uused Products by 50000+ Subscribers
4. A,B,D
5. A,B,C,D


Question : NetworkTopologyStrategy is recommended for most deployments because it is much easier to expand to multiple data
centers when required by future expansion.

1. True
2. False