All The Useful Big Data Interview Questions & Answers

What is Big Data?
Big data is a field that treats ways to analyze, systematically extract information from, or otherwise deal with data sets that are too large or complex to be dealt with by traditional data-processing application software. 

Data with many fields (columns) offer greater statistical power, while data with higher complexity (more attributes or columns) may lead to a higher false discovery rate.

Big data analysis challenges include capturing data, data storage, data analysis, search, sharing, transfer, visualization, querying, updating, information privacy, and data source

Big data was originally associated with three key concepts: volume, variety, and velocity.

The analysis of big data presents challenges in sampling, and thus previously allowing for only observations and sampling. Therefore, big data often includes data with sizes that exceed the capacity of traditional software to process within an acceptable time and value.

Source: Wikipedia

Q 1. Why is big data important for organizations?
Big data analytics is a comparatively new technology helping organizations to harness their own data and optimize its use for identifying new opportunities. Here are some of the ways Big Data is vital to organizations:

Cost reduction: It uses technologies like cloud-based analytics and Hadoop which effectively bring down costs a lot, especially when storing large amounts of data. In addition to that, analytics helps identify multiple efficient ways to increase productivity.
Faster and better decision making: Combined with the speed of Hadoop and in-built memory analytics, along with the capacity to analyze new sources of data, organizations are able to analyze vast amounts of data instantly and make decisions based on them.
Launching new products and/or services: Combing through large amounts of data gives the organizations the power to serve their customers on a superior scale while satisfying their needs instantly. This leads to the launch of new products and/or services to help grow and retain their existing customer base.

Q 2. What are the five V's of Big Data?
Here are the five V's of Big Data and how they help organizations to scale their business:

Volume: Sheer volume of data is one of the first features of Big Data helping businesses in making better and informed decisions. Velocity: Sometimes, Volume can be beaten by Velocity or speed of acquisition of data. This is vital as companies face cut-throat competition and speed can be a big factor in gaining an upper hand here.
Variety: Big Data has a major advantage in obtaining data having a lot of variety. This can help companies in the service industry where variety is considered a very important feature of gaining superiority among competitors.
Veracity: Volume and Velocity are good only when the quality of data is good, ain't that true? Big Data comes to the rescue here by providing quality data to help in accurate decision making.
Value: This is the most vital aspect. You have large amounts of data that are acquired at a very high speed. But, you need to know whether this is good enough or not. Big Data provides you with more than just data. It helps you analyze it by bringing value to the table.

Q 3. What is the distributed cache and what are its benefits?
Distributed caching is a popular method for caching storage data which has been configured across various nodes and servers in the same network. Caching the data which has been stored in similar data request pieces of information.

Benefits of Distributed Caching Method:

Reduced Network Costs
Enhanced Responsiveness
Optimized performance on the same hardware settings
Round-the-clock availability of content even during network interruptions.

Q 4. Why do we need Hadoop for Big Data Analytics?
Here are the reasons for using Hadoop in Data Science:

Engaging Data with Large Datasets
Simplified methods of Data Processing
Using its flexible schema for Data Agility
Providing linear scalable storage for Data Mining

Q 5. What is Fsck?
FSCK is an admin command in Hadoop which is used to check the HDSF File System to enable the passing of different results with different arguments during Data Analytics.

Q 6. What are the steps involved in big data solutions?
Here are the 6 steps involved in setting up any Big Data Solution:

Analyzing the Business problem to be solved
Vendor Selection for Hadoop Distribution
Selecting a Deployment Strategy, i.e. On-site, cloud-based or both
Overall Capacity Planning
Final Infrasturce Sizing
A Backup and Disaster Recovery Plan

Q 7. What is the purpose of the JPS command?
JPS(Java Virtual Machine Process Status Tool) is a command which is used to display all java based processes for a particular user in Hadoop. It is also used to check all the Hadoop Daemons like Data Node, Name Node, Resource Manager and more running on the machine.

Q 8. What are the tools used in big data processing?
Here are the 10 most useful tools used in Big Data Solutions:

Hadoop
Apache Spark
Apache Storm
Cassandra
Rapid Miner
MongoDB
R Programming Tool
Neo4j
Apache SAMOA
HPCC

Q 9. What is the difference between big data and data science?

Big Data    Vs  Data Science
Used to handle large amounts of data    - Used to analyze the data
Used for processing large amounts of data while generating insights    - Used to understand a pattern in the data sets which help in decision making.
Identified by volume, veracity, variety and velocity of data    - Identified by the processing of Big Data and the solutions it brings to the table.
Includes structured, semi-structured and unstructured data.    - Includes forecasting, decision-making prediction and classification based on the data.
Generally used by the Ecommerce, Telecommunication and Security Industries.    - Generally used for Sales, Image Recognition, Risk Analytics and Digital Advertisements
Tools used are: Spark, Hadoop and Flink    - Tools used are: SAS, Python and R

Q 10. How is big data analysis helpful in increasing business revenue?
Big data analytics can help businesses customized recommendations and suggestions using predictive analysis. Big data analytics helps companies to launch new products according to customer needs and preferences. These factors enable businesses to make more revenue, and thus companies are using big data analytics.

Q 11. What are the steps to deploy a big data solution?
Here are the 4 steps to successfully deploy a working Big Data Solution:

Finding a quality source of Data as this is where the first step of any Big Data Solution starts.
Integration of the Data Sources and a method for storing the data.
After the integration and storage of data, analyzing the data is important through data models and analytics tools.
Finally, after analyzing the data, setting up a platform for Data Visualization and Reporting for quick decision making.

Q 12. What is the diference between Big Data and Data Mining?

Big Data: It is huge, large or voluminous data, information or the relevant statistics acquired by the large organizations and ventures. Many software and data storage created and prepared as it is difficult to compute the big data manually. 
It is used to discover patterns and trends and make decisions related to human behavior and interaction technology. 

Data Mining: Data Mining is a technique to extract important and vital information and knowledge from a huge set/libraries of data. It derives insight by carefully extracting, reviewing, and processing the huge data to find out pattern and co-relations which can be important for the business. It is analogous to the gold mining where golds are extracted from rocks and sands.