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Top 50 Cassandra Interview Questions for Beginners and Experience

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Top 50 Cassandra Interview Questions for Beginners and Experience

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(1)Continuous uptime and low latency is achieved in NoSQL systems as compared to traditional relational databases.

Yes

No

Correct Answer of the above questions is :Yes

(2)What is meant by 'Active everywhere design'?

There is no single point of failure

All nodes communicate with each other

All nodes are equal

All nodes can be written to and read from

Correct Answer of the above questions is :All nodes can be written to and read from

(3)Cassandra is a __________ architecture.

3-teir

peer-to-peer

None of the options mentioned

Master-slave

Correct Answer of the above questions is :peer-to-peer

(4)Cassandra is not suitable for IoT applications.

False

True

Correct Answer of the above questions is :False

(5)Which among the following is a NoSQL db?

MongoDB

Couchbase

Cassandra

All of the options mentioned

Correct Answer of the above questions is :All of the options mentioned

(6)Which of the following statements about NoSQL databases is true?

Do not provide horizontal scalability

Support unstructured data

Do not support Query Language

All of the options mentioned

Correct Answer of the above questions is :Support unstructured data

(7)Which Linux flavour can be used for Cassandra Installation?

CentOS

Debian

Red Hat

All of the options mentioned

Correct Answer of the above questions is :All of the options mentioned

(8)Which command can be used to list all available commands/operations in Cassandra?

CAPTURE

SHOW

HELP

EXPAND

Correct Answer of the above questions is :HELP

(9)SSTable resides in memory.

False

True

Correct Answer of the above questions is :False

(10)Which type of data model does Cassandra use?

Key-value data model

Both key-value and tabular data models

Tabular data model

Multivalue model

Correct Answer of the above questions is :Both key-value and tabular data models

(11)Java instance should be running in the machine inorder to setup Cassandra.

No, you do not require

It's optional

Yes, java must be running in the machine

None of the options mentioned

Correct Answer of the above questions is :Yes, java must be running in the machine

(12)Cluster can have multiple seed nodes.

True

False

Correct Answer of the above questions is :True

(13)A bloom filter can return __________.

Bloom-filter does not help in locating data

A false negative

the exact location of the requested data

A false positive

Correct Answer of the above questions is :A false negative

(14)What are ‘seed nodes’ in Apache Cassandra?

There must be at least one seed node in a cluster

One may configure more than one seed node for added redundancy

They allow the instance to find the cluster on the very first startup

All of the options mentioned

When a node first starts, it contacts a seed node to bootstrap the gossip communication process.

Correct Answer of the above questions is :All of the options mentioned

(15)What is the default partitioner in Apache Cassandra cluster?

Murmur3Partitioner

ByteOrderedPartitioner

HashPartitioner

RandomPartitioner

Correct Answer of the above questions is :Murmur3Partitioner

(16)Cassandra attaches a timestamp to each version of the record and uses this to merge records .

No, Merge is not supported by cassandra.

Yes

No

Correct Answer of the above questions is :Yes

(17)Row cache is an in-memory cache, which stores recently read rows.

True

False

Answe:-True

(18)The simplest and the fastest read path is when the record is present in the __________.

Commit log

Row Cache

Partition Key cache

Bloom filter

Correct Answer of the above questions is :Row Cache

(19)Authorization capabilities for Cassandra use the familiar__________ security paradigm to manage object permissions.

ROLLBACK

COMMIT

GRANT

None of the options mentioned

Correct Answer of the above questions is :GRANT

(20)To be able to read data from compressed blocks, Cassandra consults __________.

Row cache alone

Compression offsets

commit log

compressed key cache

Correct Answer of the above questions is :Compression offsets

(21)Pick the correct statements.

Row cache is an in-memory cache.

Key Cache maps recently read partition keys to specific SSTable offset.

Compaction offsets keeps the offset mapping information for compressed blocks.

Partition Indexes are sorted partition keys mapped to their SSTable offsets.

All of the options mentioned

Correct Answer of the above questions is :All of the options mentioned

(22)What is C-A-P, in CAP theorem?

Concurrency 2) Atomicity and 3) Partition tolerance

Consistency 2) Availability and 3) Partition tolerance

Consistency 2) Atomicity and 3) Partition tolerance

Concurrency 2) Availability and 3) Primary indexing

Correct Answer of the above questions is :Consistency 2) Availability and 3) Partition tolerance

(23)Is Timestamp an optional field in Column?

False

True

Correct Answer of the above questions is :True

(24)Pick the correct statement.

Under each column-family, there can be multiple rows.

All the options mentioned

A cluster can have more than one key-space.

There can be one or more column-family under a key-space.

Correct Answer of the above questions is :All the options mentioned

(25)Pick the correct statement.

Each keyspace has at least one and often many column families.

None of the options mentioned

Any column cannot be added to a column family after creation.

Column families do not represent the structure of your data.

Correct Answer of the above questions is :Each keyspace has at least one and often many column families.

(26)Which among the following is not a Replica Placement strategy?

Simple Strategy

Network Topology Strategy

None of the options mentioned

Old Network Topology Strategy

Correct Answer of the above questions is :None of the options mentioned

(27)Keyspace is analogous to __________ in realtional world.

columns

database

data types

records

Correct Answer of the above questions is :database

(28)Which among the following is the right syntax for 'Using a Keyspace'?

REUSE

USE CURRENT

USE

USE

Correct Answer of the above questions is :USE

(29)Pick the correct statement.

Primary key is a column.

Primary key is used to uniquely identify a row.

Primary key can be composed of more than one column.

Primary key is mandatory in creating a table.

All of the options mentioned

Correct Answer of the above questions is :All of the options mentioned

(30)Which of the following statements is true about CQL?

CQL does not support joins.

CQL model is close to SQL.

CQL supports prepared statements.

All of the options mentioned

CQL supports joins.

Correct Answer of the above questions is :All of the options mentioned

(31)What is the primary language for communicating with the Apache Cassandra™ database?

CQL

None of the options mentioned

SQL

HQL

Correct Answer of the above questions is :CQL

(32)Which directory contains Cassandra configuration files?

lib

interface

bin

conf

Correct Answer of the above questions is :conf

(33)Defining a primary key is mandatory while creating a table.

True

False

Answer:True

(34)Which Linux flavour can be used for Cassandra Installation?

Red Hat

All of the options mentioned

CentOS

Debian

Correct Answer of the above questions is :All of the options mentioned

(35)What can also be attributed as wide-row in Apache Cassandra?

Foreign Key

Clustering Key

Primary Key

Compound Key

Correct Answer of the above questions is :Compound Key

(36)Which collection type is used to maintain uniqueness of data structure?

Map

Heap

List

Set

Correct Answer of the above questions is :Set

(37)CQL features include __________.

All of the options mentioned

Nested user-defined types

Timestamps precise to the millisecond

Configurable counter cache

Correct Answer of the above questions is :All of the options mentioned

(38)How does Cassandra store data?

By dividing all data evenly around a cluster of nodes, which can be visualized as a ring.

By storing all data in the master node and directing them to slaves as per request.

There is no specified scheme set for data storage.

By storing data in slave nodes and storing its offsets in master node.

Correct Answer of the above questions is :By dividing all data evenly around a cluster of nodes, which can be visualized as a ring.

(39)NoSQL db - Cassandra is of type __________.

Graph databases

Document databases

Wide-column stores

Key-value databases

Correct Answer of the above questions is :Wide-column stores

(40)Which of the following is not part of SSTable?

Bloom filter

Data

Memtable

Index

Correct Answer of the above questions is :Memtable

(41)What is the use of commit log?

Monitoring

Crash-recovery

Performance Improvement

Logging

Correct Answer of the above questions is :Crash-recovery

(42)What is the primary language for communicating with the Apache Cassandra database?

Cassandra do not support query language.

HQL

SQL

CQL

Correct Answer of the above questions is :CQL

(43)In cassandra consistency is achieved through consistency tuning mechanisms.

False

True

Correct Answer of the above questions is :True

(44)Minimum JVM version required for Cassandra is __________.

1.3

1.6

1.4

1.5

Correct Answer of the above questions is :1.6

(45)__________ is a collection of related nodes.

Data center

Ring

Node

Cluster

Correct Answer of the above questions is :Data center

(46)Cassandra supports ACID transactions?

False

True

Correct Answer of the above questions is :False

(47)Which OS does Cassandra support?

Both Windows and Linux

None of the options mentioned

Linux

Windows

Correct Answer of the above questions is :Both Windows and Linux

(48)Primary key is a column that is used to uniquely identify a row.

False

True

Correct Answer of the above questions is :True

(49)What can be used to monitor clock drifts?

SSH

NTP

HTTP

JMX

Correct Answer of the above questions is :NTP

(50)__________ can be configured per table for non-QUORUM consistency levels.

Write repair

Write damage

Read damage

Read repair

Correct Answer of the above questions is :Read repair

(51)Replication can be configured to work across __________.

Single Data center

Single Ring

single cloud availability zones

one or more Data Centers

Correct Answer of the above questions is :one or more Data Centers

(52)Which technique is used for error correction for every compressed block?

Parity bit

CRC

Hashing

ECC

Correct Answer of the above questions is :CRC

(53)Cassandra will keep appending the records into the Commit Log and then to the memtable.

False

True

Correct Answer of the above questions is :True

(54)What percentage is the default threshold of memory used for flushing of the largest Memtables?

75

80

50

65

Correct Answer of the above questions is :65

(55)CQL features include __________.

Nested user-defined types

All of the options mentioned

Timestamps precise to the millisecond

Configurable counter cache

Correct Answer of the above questions is :All of the options mentioned

(56)User accounts may be altered and dropped using the __________ Query Language.

Cassandra

Sqoop

None of the options mentioned

Hive

Correct Answer of the above questions is :Cassandra

(57)Cassandra promotes __________ operation.

Read-after-write

Read-before-read

Read-before-write

Write-after-write

Correct Answer of the above questions is :Read-before-write

(58)Which directory contains Cassandra configuration files?

bin

interface

conf

lib

Correct Answer of the above questions is :conf

(59)Which among the following is not a performance measurement tool?

iostat

cmstat

None

dstat

Correct Answer of the above questions is :None

(60)How does Murmur3Partitioner work?

None of the options mentioned

Order keys as per byte values

Order values

Fast hash-based partitioner

Correct Answer of the above questions is :Fast hash-based partitioner

(61)Partitioners supported by Cassandra are __________.

All of the options mentioned

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