Top Big Data Interview Questions & Answers

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Big Data and Hadoop Interview questions

 

Big data is booming in the market. A powerful tool being able to store, analyze and visualize in a real time, it helps you know how others perceive your products so that you can adapt them. On top of that, you will be able to find sensitive information that is not stored in a protective manner. The demand for big data professionals is on a constant rise and it is expected that the momentum will continue in scores of startups appeared in this segment. With big data launching to play a significant role in every facet of businesses, we bring you the top most popular Big Data & hadoop interview questions and answers.

 

To help you prepare better for your next Big Data interview, here are some of the carefully picked Big Data hadoop interview questions that are generally asked:

 

Q1. What are the four features of Big Data?

 

Ans. The four V’s renders the perceived value of data. It is as valuable as the business results bringing improvements in operational efficiency.

  • Volume
  • Velocity
  • Variety
  • Veracity

 

Q2. How does A/B testing work?

 

Ans. A great method for finding the best online promotional and marketing strategies for your organization, it is used to check everything from search ads, mails to website copy. The main goal of A/B testing is to figure out any modification to a webpage to maximize result of an interest.

 

Q3. What do you mean by logistic regression?

 

Ans. Also known as logit model, Logistic Regression is a technique to predict the binary result from a linear amalgamation of predictor variables.

 

Q4. What are some of the interesting facts about Big Data?

 

Ans.

  • According to the experts of industry, the digital information will grow to 40 zettabytes by 2020
  • Surprisingly, every single minute of a day, more than 500 sites come into existence. This data is certainly vital and also awesome
  • With the increase in number of smartphones, companies are funneling their money into it by carrying mobility to the business with apps
  • It is said that Walmart collects 2.5 petabytes of data every hour from its consumer transactions

 

 

Q5. How much data is enough to get valid outcome?

 

Ans. Collecting data is like tasting wine- the amount should be accurate. All the businesses are different and measured in different ways. Thus, you never have enough data and there will be no right answer. The amount of data required depends on the methods you use in order to have an excellent chance of obtaining vital results.

 

Q6. How Big Data can help increase the revenue of the businesses?

 

Ans. Big data is about using data to expect future events in a way that progresses the bottom line. There are oodles of ways to increase profit. From email to a site, to phone calls and interaction with people, this brings information about the client’s performance. Undoubtedly, a deeper understanding of consumers can improve business and customer loyalty. Big data offers an array of advantages to the table, all you have to do is use it more efficiently in order to an increasingly competitive environment.

 

Q7. What are the three modes in which Hadoop can run?

 

Ans.

  • Standalone mode
  • Pseudo Distributed mode (Single node cluster)
  • Fully distributes mode (Multiple node cluster)

 

Also Read>>Top Big Data Certifications That Will Boost Your Career

 

Q8. What are the responsibilities of a data analyst?

 

Ans.

  • Helping marketing executives know which products are the most profitable by season, customer type, region and other feature
  • Tracking external trends relatives to geographies, demographic and specific products
  • Ensure customers and employees relate well
  • Explaining the optimal staffing plans to cater the needs of executives looking for decision support

 

Q9. Name some of the important tools useful for Big Data analytics?

 

Ans.

  • NodeXL
  • KNIME
  • Tableau
  • Solver
  • OpenRefine
  • Rattle GUI
  • Qlikview

 

Also Read>>Career Advantages of Hadoop Certification!

 

Q10. What do you know about collaborative filtering?

 

Ans. A set of technologies that forecast which items a particular consumer will like depending on the preferences of scores of individuals. It is nothing but the tech word for questioning individuals for suggestions.

 

Q11. State some key components of a Hadoop application?

 

Ans.

  • HDFS
  • YARN
  • MapReduce
  • Hadoop Common

 

Q12. What is block in Hadoop Distributed File System (HDFS)?

 

Ans. When the file is stored in HDFS, all file system breaks down into a set of blocks and HDFS unaware of what is stored in the file. A block size in Hadoop must be 128MB. This value can be tailored for individual files.

 

Q13. How will you define checkpoint?

 

Ans. It is a main part of maintaining filesystem metadata in HDFS. It creates checkpoints of file system metadata by joining fsimage with edit log. The new version of fsimage is named as Checkpoint.

 

Q14. What should be carried out with missing data?

 

Ans. It happens when no data is stored for the variable and data collection is done inadequately. Employees who have experience must analyze data that wary in order to decide if they are adequate.

 

Also Read>>A QUICK READ ON 5 BIG DATA CONCEPTS!

 

Q15. What are the main challenges big data companies normally encounter?

 

Ans. A majority of companies across different industries are fighting to extract optimum value for the data in their possession. The important challenges are the four Vs delivering values and getting things done.

 

Q16. Define Active and Passive Namenodes?

 

Ans. Active NameNode runs and works in the cluster whereas Passive NameNode has comparable data like active NameNode.

 

Also Read>>Top Hadoop Interview Questions & Answers

 

Q17. What is JPS used for?

 

Ans. It is a command used to check NodeManager, NameNode, ResourceManager and Job Tracker are working on the machine.

 

Q18. What types of biases can happen through sampling?

 

Ans.

  • Survivorship bias
  • Selection bias
  • Under coverage bias

These big data interview questions and answers will help you get a dream job of yours. You can always learn and develop new Big Data skills by taking one of the best Big Data courses.


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Twinkle kapoor

Though from a techie background, her interest in writing on plethora of topics has made her today an experienced writer. She has written articles, blogs and web page content for oodles of websites.

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