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

Question : You have been given below table definition

CREATE TABLE HADOOEXAM(

COURSE_TITLE text,
COURSE_ADDED_YEAR int,
COURSE_ADDED_DATE timestamp,
COURSE_DETAIL text,
USER_ID UUID,
COURSE_ID TIMEUUID,
PRIMARY KEY ((COURSE_TITLE),COURSE_ADDED_YEAR)));

What would be the result, when you run the below query?

SELECT * FROM HADOOEXAM WHERE COURSE_TITLE='CASSANDRA' AND COURSE_ADDED_YEAR=2017;

What is the expected result?

1. It will return all the courses which matches with the COURSE_TITLE='CASSANDRA' AND
COURSE_ADDED_YEAR=2017

2. It will return all the courses which is stored in the same partition where record for
COURSE_TITLE='CASSANDRA' stored

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4. This will say invalid query


Correct Answer : Get Lastest Questions and Answer :
Explanation: As we have COURSE_ADDED_YEAR is a cluster key, hence query is correct.




Question : You have been given below table definition

CREATE TABLE HADOOEXAM(

COURSE_TITLE text,
COURSE_ADDED_YEAR int,
COURSE_ADDED_DATE timestamp,
COURSE_DETAIL text,
USER_ID UUID,
COURSE_ID TIMEUUID,
PRIMARY KEY ((COURSE_TITLE),COURSE_ADDED_YEAR)));

What would be the result, when you run the below query?

SELECT * FROM HADOOEXAM WHERE COURSE_TITLE='CASSANDRA' AND COURSE_ADDED_YEAR <=2017;

What is the expected result ?

1. It will return all the courses which matches with the COURSE_TITLE='CASSANDRA' AND
COURSE_ADDED_YEAR<=2017

2. It will return all the courses which is stored in the same partition where record for
COURSE_TITLE='CASSANDRA' stored

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4. This will say invalid query


Correct Answer : Get Lastest Questions and Answer :
Explanation: As we have COURSE_ADDED_YEAR is a cluster key, hence query is correct. It is like range query on
sorted column. You cannot do with other non-cluster columns.




Question : What does UPSERT means in Cassandra?

1. A failed UPDATE

2. A failed INSERT

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4. INSERTs may cause UPDATEs; UPDATEs may causes INSERTs


Correct Answer : Get Lastest Questions and Answer :
Explanation:

Related Questions

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Question : . In Cassandra insertions or updates of two or more rows in the same partition are treated as one write
operation.

1. True
2. False


Question : If you are using write consistency level of QUORUM with a replication factor of

1. Cassandra will replicate the write to all nodes in the cluster and wait for acknowledgement from two
nodes.

2. Cassandra will replicate the write to all nodes in the cluster and wait for acknowledgement from one of
the nodes.

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nodes.

4. Cassandra will replicate the write to all nodes in the cluster and does not wait for acknowledgement from
two nodes.



Question : Which of the following is true ?

1. Cassandra uses client-side timestamps to determine the most recent update to a column.

2. Cassandra uses server-side timestamps to determine the most recent update to a column.

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to a column.

4. Cassandra uses user provided timestamps to determine the most recent update to a column.



Question : Batch operation is isolated if it includes changes to more than one partition.

1. True
2. False


Question : All writes to a replica node are recorded in which of the following before they are acknowledged as a success



1. In Memory

2. commit log

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4. 1,2

5. 1,2 and 3


Question : In Cassandra data updates are performed as "compare (validation a condition) before setting (read before write)
" is known as


1. Consistent Transaction

2. Eventual Consistent Transaction

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4. Durable Transaction