Top Hadoop Interview Questions [Questions Asked in Different IT Companies]

Today we will see some of the top Hadoop interview questions which are being asked in many IT company’s interviews. We have collected these top Hadoop interview questions based on the feedback shared by many of our readers.

Earlier, we asked our readers to share the Hadoop developer interview questions which they have faced in the interview and thanks to all those who shared it.

Here we will be listing those big data Hadoop interview questions company wise so that you can have an idea. Prepare for these top Hadoop developer interview questions and do well in the exam.

If you are new here, you should also check our other Hadoop interview series- Scenario based Hadoop Interview Questions, Capgemini Hadoop interview questions and answers, Pig interview questions and answers.

Top Hadoop Interview Questions In IT Companies [Both Developer & Admin Questions]

Let’s get started and see the top Hadoop interview questions and answers asked in various IT companies.

Absolute Data Hadoop Developer Interview Questions

Hadoop Developer Interview Questions Asked in Absolute Data

• What is the difference between group and co-group
• Why we use PIG and what is difference from Hive –Check Pig Interview questions and answers
• Let’s say you have a large file, how you will take that in Hadoop system – Check HDFS File Processing for Answer
• What are the options available to copy a file from local server to Hadoop cluster – Answer
• What is the difference between managed table and external table and when to use internal table and external table in hive? –Answer
• What is SerDe and where you have used it in your project
• How you will move the entire MySQL database to Hadoop –Check Sqoop Import Function for Answer
• How to import all the database from RDBMS except table1 and table2 in Hadoop –Check Sqoop Import Function for Answer
• Can you import an RDBMS table into the Hive table directly, if yes, how?
• Can you import an RDBMS table to hive partition directly?
• Can we export a partitioned table to RDBMS?
• What is the difference when we use mapper 1 and 4 in Sqoop import
• What is skewed join in Hive
• How you will optimize Hive queries – Check Hive Performance Tunning for Answer
• What is combiner and partition in MapReduce and where it takes place- Answer
• When you want any job to run/code execution in MapReduce, do you need to provide that file to all the JT, TT or only to NameNode?
• How you can create a workflow in Oozie

Robert Bosch Hadoop Interview Questions

Hadoop Developer Interview Questions asked in Robert Bosch Interview

• why you use JDBC in Sqoop
• write a command to import customer table in Hadoop –Check Sqoop Import Function for Answer
• what is the difference between an external table and internal table –Answer
• what is the mapper in Sqoop and how you decide the number of mapper in Sqoop
• in the external table, can any external location can be your data location
• Which language you use in flume configuration
• Where you can specify the input and output location in MapReduce program

Capgemini Hadoop Interview Questions

Hadoop Developer Interview Questions asked in Capgemini Interview

• What is serialization
• How to remove the duplicate records from a hive table
• How to find the number of delimiter from a file
• Replace a certain word from a file using Unix
• How to import a table without a primary key
• What is cogroup in pig
• how to write a UDF in Hive
• how you can join two big tables in Hive
• the difference between order by and sort by

Adobe Hadoop Interview Questions

Hadoop Developer Interview Questions asked in Adobe Interview – 1st Round

• What is serialization
• How to remove the duplicate records from a hive table
• How to find the number of delimiter from a file
• Replace a certain word from a file using Unix
• How to import a table without a primary key
• What is cogroup in pig
• how to write a UDF in Hive
• how you can join two big tables in Hive
• the difference between order by and sort by

Hadoop Developer Interview Questions asked in Adobe Interview- 2nd Round

• What is Fact Table and Dimension Table (When I said that I am aware of Dataware house concept)
• What type of data we should store in Fact table and dimension table
• There is a string in a Hive column, how you will find the count of a character. For example, the string is “hdfstutorial”, then how to count number of ‘t’.
• There is a table in Hive, and the columns are student id, score and year. Find the top 3 students based on the score in each year.
• There is a table having 500 Million records. Now you want to copy the data of that table in some other table, what best approach you will choose.
• You have 10 tables, and there are certain join conditions you have to put and then the result needs to be updated in another table. How you will do it and what best practice you will follow
• Which all analytical functions you have used in Hive
• Why we use bucketing
• what is actually hapeening in bucketing and when we apply
• How bucketing is different from Partition and why we use it
• If you have a bucketed table then can you take those records to Sqoop directly

IBM Hadoop Interview Questions

Hadoop Developer Interview Questions asked in IBM Interview

• What is Hive variable
• What is Object inspector
• Please explain Consolidation in hive
• What are the differences between MapReduce and YARN
• Can you differntiate between Spark and MapReduce
• Explain RDD and data frames in spark
• Can you write the syntax for Sqoop import
• WHat do you know about Hive views
• Difference between Hive external table and Hive managed Table
• What are the differences between HBase and Hive
• What are Orderby, sortby, and clustered by
• What is Speculative execution
• Which all Alter column command in hive you have worked
• What is lazy evaluation in pig?
• What is dynamic partition and static partition in hive?
• What is the use of partitions and bucketing in hive?
• Explain the flow of MapReduce program?
• What is default partition in MapReduce and how can we override it?
• What is difference between key class and value class in MapReduce?
• What is the level of sub queries in hive?
• What is transformation and action in spark?

Wrapping it up!

These were some of the top Hadoop interview questions and answers asked in various Hadoop interviews. If you are also preparing for the Hadoop interviews, you must prepare for these Hadoop interview questions and crack the interviews.

Here we have only listed questions and if you feel some difficulty with any questions, please comment and we will share the detailed answers.