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

Question : You have following table definition

CREATE TABLE TRINING_COURSE (
id uuid,
course_sequence int,
course_id uuid,
title text,
category text,
trainer text,
PRIMARY KEY (id, course_sequence ) );

ALTER TABLE TRINING_COURSE ADD LOCATION map;
ALTER TABLE TRINING_COURSE ADD emails set;

And you also apply the following CQL

CREATE INDEX MYINDEXVALUE ON TRINING_COURSE (LOCATION);
CREATE INDEX MYINDEXKEY ON TRINING_COURSE (KEYS(LOCATION));

Which statement is correct ?

1. There will be two indexes created one on Location keys and other on Location values

2. There will be only one index created on Location keys and other will be auto dropped on Location values

3. Access Mostly Uused Products by 50000+ Subscribers

4. When you try to create index on Location keys, it will give error.


Correct Answer : Get Lastest Questions and Answer :
Explanation: Indexes on the keys and values of a map cannot co-exist. For example, if you created MYINDEXVALUE,
you would need to drop it to create an index on the map keys using the KEYS keyword and map name in nested parentheses:

DROP INDEX MYINDEXVALUE;
CREATE INDEX MYINDEXKEY ON TRINING_COURSE (KEYS(LOCATION));





Question : You have following table definition

CREATE TABLE TRINING_COURSE (
id uuid,
course_sequence int,
course_id uuid,
title text,
category text,
trainer text,
PRIMARY KEY (id, course_sequence ) );

ALTER TABLE TRINING_COURSE ADD emails set;

Now, you need to select all rows having email id as 'admin@hadoopexam.com' , which of the following are correct syntax ?

1. SELECT * FROM TRINING_COURSE WHERE emails CONTAINS 'admin@hadoopexam.com' ;

2. SELECT * FROM TRINING_COURSE WHERE emails HAVING 'admin@hadoopexam.com' ;

3. Access Mostly Uused Products by 50000+ Subscribers

4. SELECT * FROM TRINING_COURSE WHERE emails IN ('admin@hadoopexam.com' );


Correct Answer : Get Lastest Questions and Answer :
Explanation: using the CONTAINS condition in the WHERE clause, you can filter the set collection data.




Question : You have following table definition

CREATE TABLE TRINING_COURSE (
id uuid,
course_sequence int,
course_id uuid,
title text,
category text,
trainer text,
PRIMARY KEY (id, course_sequence ) );

CREATE INDEX MYINDEXVALUE ON TRINING_COURSE (LOCATION);

Now, you need to select all rows having TRAINING_COURSE ORGANIZED IN a˜Mumbaia which of the following are correct syntax ?

1. SELECT * FROM TRINING_COURSE WHERE LOCATION CONTAINS 'MUMBAI';

2. SELECT * FROM TRINING_COURSE WHERE LOCATION IN { 'MUMBAI' };

3. Access Mostly Uused Products by 50000+ Subscribers

4. SELECT * FROM TRINING_COURSE WHERE LOCATION HAVING 'MUMBAI';


Correct Answer : Get Lastest Questions and Answer :
Explanation: filter the data using a value in the LOCATION map using the CONTAINS condition in the WHERE clause.
The statement is the same one you use to filtering the data in a set or list.

Related Questions

---

Question : You are working in an Investment Bank, and they have subscribed data feeds from BloomBerg, which delivers
data in various different format e.g. CSV file, Direst database access either RDBMS or NOSQL(Cassandra)
and daily incremental data. Which of the following you can use in Cassandra to load data or migrate data from one
Cassandra cluster to another.
A. CQL INSERT command
B. CQL COPY command
C. Loading CSV file directly.
D. sstableloader


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


Question : A file to which Cassandra appends changed data for recovery in the event of a hardware failure is called.


1. commit log

2. memtable

3. SSTable

4. redo log



Question : Cassandra addresses the problem of failures by employing



1. Master-slave Architecture

2. peer-to-peer gossip communication protocol

3. peer-to-peer TCP communication protocol

4. peer-to-peer UDP communication protocol



Question : Which of the following is, A Cassandra table-specific, in-memory data structure that resembles a write-back
cache.



1. commit log

2. memtable

3. SSTable

4. redo log



Question : Fill in blanks
Each time the memory structure is full, the data is written to disk in an SSTable data file. All writes are
automatically partitioned and replicated throughout the cluster.
Cassandra periodically consolidates SSTables using a process called __________, discarding obsolete data marked
for deletion with a ___________.
To ensure all data across the cluster stays consistent, various repair mechanisms are employed.

1. compaction, tombstone

2. tombstone, compaction

3. Serialization, compaction

4. repair, compaction

5. tombstone, repair



Question : What is the meaning of coordinator node.



1. master node in Cassandra cluster.

2. Node which contain master copy of any data.

3. Client read or write requests can be sent to any node in the cluster, and
When a client connects to a node with a request, that node serves as the coordinator for that particular client operation

4. Node which contain configuration for entire cluster.