Showing posts with label Apache Cassandra Objective type Questions and Answers pdf. Show all posts
Showing posts with label Apache Cassandra Objective type Questions and Answers pdf. Show all posts

Friday, June 16, 2017

Latest Apache Cassandra Multiple choice Questions and Answers pdf

11: Talk about the concept of tunable consistency in Cassandra.
Tunable Consistency is a characteristic that makes Cassandra a favored database choice of Developers, Analysts and Big data Architects. Consistency refers to the up-to-date and synchronized data rows on all their replicas. Cassandra’s Tunable Consistency allows users to select the consistency level best suited for their use cases. It supports two consistencies – Eventual Consistency and Strong Consistency.

12: What are the three components of Cassandra write?
The three components are:
Commitlog write
Memtable write
SStable write
Cassandra first writes data to a commit log and then to an in-memory table structure memtable and at last in SStable.

13: Explain zero consistency.
 In zero consistency the write operations will be handled in the background, asynchronously. It is the fastest way to write data.

14: Mention what are the values stored in the Cassandra Column?
There are three values in Cassandra Column. They are:
Column Name
Value
Time Stamp

15: What do you understand by Kundera?
Kundera is an object-relational mapping (ORM) implementation for Cassandra which is written using Java annotations.

16: What is the concept of SuperColumn in Cassandra?
Cassandra SuperColumn is a unique element consisting of similar collections of data. They are actually key-value pairs with values as columns. It is a sorted array of columns, and they follow a hierarchy when in action.

17: When do you have to avoid secondary indexes?
Try not using secondary indexes on columns containing a high count of unique values as that will produce few results.

18: List the steps in which Cassandra writes changed data into commitlog?
Cassandra concatenates changed data to commitlog. Then Commitlog acts as a crash recovery log for data. Until the changed data is concatenated to commitlog, write operation will never be considered successful.

19: What is the use of “ResultSet execute(Statement statement)” method?
This method is used to execute a query. It requires a statement object.

20: What is Thrift?
Thrift is the name of the Remote Procedure Call (RPC) client used to communicate with the Cassandra server.

Read More Questions:
Apache Cassandra Interview Questions Part1
Apache Cassandra Interview Questions Part2
Apache Cassandra Interview Questions Part3
Apache Cassandra Interview Questions Part4
Apache Cassandra Interview Questions Part5