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



Question : Freshman, Sophomore, Junior, Senior are disjoint sets, and in this case covers, too.
: Freshman, Sophomore, Junior, Senior are disjoint sets, and in this case covers, too.
1. True
2. False

Correct Answer : 1

Explanation:




Question : Employee is not disjoint


: Employee is not disjoint
1. True
2. False


Correct Answer : 1
Explanation: Because secretary can be an engineer. Hence, not covering as well as they are not disjoint.
Disjointness constraint: Sets of subtype entities are disjoint
from one another (i.e., the sets are mutually exclusive). An entity can be an element of at most one entity




Question : Select all the features provided by Cassandra, from below list.
A. Cassandra is a partitioned row store database
B. Automatic data distribution: Cassandra provides automatic data distribution across all nodes that participate in a ring or
database cluster.
C. Built-in and customizable replication: Cassandra also provides built-in and customizable replication, which stores
redundant copies of data across nodes that participate in a Cassandra ring.
D. Cassandra supplies linear scalability

: Select all the features provided by Cassandra, from below list.
1. A,B,C
2. B,C,D
3. A,C,D
4. A,B,C,D

Correct Answer : 4
Explanation: Cassandraas built-for-scale architecture means that it is capable of handling petabytes of
information and thousands of concurrent users/operations per second.

Cassandra is a partitioned row store database: Cassandra's architecture allows any authorized user to connect to any node in
any data center and access data using the CQL language.
For ease of use, CQL uses a similar syntax to SQL. The most basic way to interact with Cassandra is using the CQL shell,
cqlsh. Using cqlsh, you can create keyspaces and tables,
insert and query tables, plus much more. If you prefer a graphical tool, you can use DataStax DevCenter. For production,
DataStax supplies a number drivers so that CQL statements
can be passed from client to cluster and back.

Automatic data distribution: Cassandra provides automatic data distribution across all nodes that participate in a ring or
database cluster. There is nothing programmatic that a
developer or administrator needs to do or code to distribute data across a cluster because data is transparently partitioned
across all nodes in a cluster.

Built-in and customizable replication: Cassandra also provides built-in and customizable replication, which stores redundant
copies of data across nodes that participate in
a Cassandra ring. This means that if any node in a cluster goes down, one or more copies of that nodeas data is available on
other machines in the cluster. Replication can be
configured to work across one data center, many data centers, and multiple cloud availability zones.

Cassandra supplies linear scalability: Cassandra supplies linear scalability, meaning that capacity may be easily
added simply by adding new nodes online.
For example, if 2 nodes can handle 100,000 transactions per second, 4 nodes will support 200,000 transactions/sec
and 8 nodes will tackle 400,000 transactions/sec



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

 : You are working in an Investment Bank, and they have subscribed data feeds from BloomBerg, which delivers
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.

 : 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


: 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.


 : Which of the following is, A Cassandra table-specific, in-memory data structure that resembles a write-back
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.
 : Fill in blanks
1. compaction, tombstone

2. tombstone, compaction

3. Serialization, compaction

4. repair, compaction

5. tombstone, repair



Question : What is the meaning of coordinator node.


 : 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.