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

Question : You have been given below conceptual data model

And you have below Access pattern, which of the following is valid table design

where rating=? and publish_date>?


1. A
2. B
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4. D

Correct Answer : Get Lastest Questions and Answer :
Explanation: In this case we know, the rating is equality operator. Hence, need to be part of primary key.
Course_name is enough to uniquely identify the course, hence we need it to course_name as clustering key. publish_date is
inequality operator hence, it should be part of clustering key as well. Here, our key attribute(title) != query attributes.




Question : You have been given below conceptual datamodel for HadoopExam Inc online training institute.

Please find the correct query for given access pattern

where author_id = ? (All the courses created by an author)


1. A
2. B
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4. D

Correct Answer : Get Lastest Questions and Answer :
Explanation: as we know this is a 1 to many relationship. Now criteria for access pattern in author_id. However, to
uniquely identify a row , we should have a course_id as well included. Email and author_name must be static column, because
they are stored only once per partition. Our partition key is author_id and author will have its own name and email id, which
we can store as a static column.





Question :

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

Correct Answer : Get Lastest Questions and Answer :
Explanation: as we know this is a 1 to many relationship. Now criteria for access pattern in author_id. However, to
uniquely identify a row, we should have a course_id as well included. Email and author_name must be static column, because they
are stored only once per partition. Our partition key is author_id and author will have its own name and email id, which we can
store as a static column.

As we have range query based on publish date, hence publish_date should be part of primary key as a clustering column.

Related Questions

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Question : Which of the following aggregation functions are supported by Cassandra as of now ?


1. SUM

2. MAX

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4. COUNT

5. AVG



Question : Which of the following statement is correct for Counter data type

1. They are always 100% accurate

2. You can do add, subtract, increment and decrement current value

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4. 1 and 3

5. 2 and 3



Question : You have been given a Cassandra cluster (Ring) with nodes, spread across two availability zones (AWS : amazon
webservice) and new KeySpace created
by Admin named AcmeKeySpace with Replication factor 3. Select correct statement.
A. Whatever data updates are done can not be replicated to another availability zone.
B. Whatever data inserts are done can not be replicated to another availability zone.
C. Whatever data updates are done , automatically replicated to another availability zone.
D. Whatever data inserts are done , automatically replicated to another availability zone.


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


Question : cassandra database is not good for, which of the following datatypes?


1. large amounts of structured

2. large amounts of semi-structured

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4. large amounts of XML data

5. None of the above



Question : Select correct statement, which applies for Cassandra NoSQL database.
A. Cassandra delivers continuous availability
B. Cassandra delivers linear scalability
C. Cassandra has operational simplicity across many commodity servers
D. Cassandra can have single point of failure.


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


Question : You have been given a Cassandra cluster (Ring) with nodes, and you want to create new KeySpace and insert data
for your mobile application named AcmeApp.

1. You have to connect primary node in Ring and needs to create Database connection with it.

2. You can connect any two nodes (Defined by Admin) in Ring and needs to create Database connection any of
these two nodes.

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4. You can connect any nodes in Ring but at a time you can use only one node from ring for your database
operations.