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

Question : All the statements, you write in batch will be executed in order of defined

1. True
2. False

Correct Answer : Get Lastest Questions and Answer :
Explanation: No, all the statements defined in batch are executed concurrently and not in the defined order.




Question : You should use Cassandra client side join, if resources don't support the necessary data duplication

1. True
2. False

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Explanation: Yes, you can use Cassandra client side joins. However, you should still avoid this, because of
performance issue.
You only do, when your database design does not support joined data set in Cassandra Schema.





Question : Which is true for Cassandra?

1. Cassandra supports join, but it needs to be avoided.

2. Cassandra does not support join at all

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4. If you have data in 3rd normal form then only you can apply joins in Cassandra


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Explanation: No, joins are basically antithetical to the core design concepts in Cassandra. They can only be done
client side or via a distributed analytics tool.

Related Questions

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Question : Which of the following is correct for collections in Cassandra table ?

1. Use collections when you want to denormalize a small amount of data.

2. Use collections when you want to store a small amount of data.

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4. 1 and 2

5. 1,2 and 3



Question : Which of the following statement true, with regards to Cassandra Index?


1. An index provides a means to access data in Cassandra using attributes other than the partition key.

2. You can index collection columns

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4. 1 and 2

5. 1 and 3



Question : The more unique values that exist in a particular column, the more overhead you will have, on average, to query
and maintain the index.

1. True
2. False


Question : In which of the following scenario indexes should be avoided?

A. On high-cardinality columns
B. In tables that use a counter column
C. On a frequently updated or deleted column.
D. To look for a row in a large partition unless narrowly queried


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


Question : You have a Books database with following columns

BOOK_TITEL
BOOK_AUTHOR
BOOK_PRIMARY_KEYWORD

Assume, each book is written by individual author and one author has written only one book. Its possible that primary keyword
can be shared among various books. There are almost 10M books in this table. Which of the following is correct with regards to
index?

1. You can create index on both BOOK_AUTHOR and BOOK_PRIMARY_KEYWORD

2. You can create index on BOOK_AUTHOR and avoid on BOOK_PRIMARY_KEYWORD

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4. On millions record table, we should not have index any columns.



Question : You must always create index to frequently updated or deleted column

1. True
2. False