In this post, we will see the questions asked in the 1st round of Dunnhumby company Interview for 1.5+ year of experience guy in big data field.

Let’s see the questions:

1) Explain your projects on which you worked till now and what is your role in that?
2) Name the tools and technologies on which you get a chance to worked till date?
3) What is the difference between Static and Dynamic partitioning in Hive?
4) What is the difference between narrow and wide transformation in apache spark? Explain with examples.
5) What is the difference between repartition and coalesce in apache spark?
6) what are the different types of modes in which you can submit your spark jobs? Explain each of them.
7) When you are submitting your spark jobs then how the process works in backend, explain that?
8) In Spark, what is the difference between cores and executors?
9) What is the difference between External and Internal table in hive?
10) Suppose we create manual partitions in the hive data-warehouse table directory, now we are writing the query to see the records for that manually inserted partitions. In this way can we able to see the records or not on the hive terminal if not then how we can correct this?
11) How we can delete the partitions of table in hive using command?
12) Write a sql query to find out the distinct ids from a table whose comes out more than 1 and greater than 200.
13) Write the spark command to read csv file.
14) What is the difference between Pandas dataframe and spark dataframe? In which condition you can prefer using pandas dataframe and in which condition you can prefer to use spark dataframe.
15) Write the spark command to add new column in the dataframe.
16) Write the spark command to rename existing column in the dataframe.
17) Suppose there is one dataframe in which existing columns are id and name. Now you have to introduced and new column and name as department column then you have to assign values in this department column as follow:
if id less than 100 then assign “HR”, if id greater than 99 and id less than 200 then assign “admin”.
18) Did you worked on DataWarehouse?

This interview was held around for 60 minutes through Zoom Video Call.

Check out the given link for knowing about this company: https://www.dunnhumby.com/

Check out the given link for knowing about this company rating on glassdoor: https://www.glassdoor.co.in/Reviews/dunnhumby-Reviews-E195922.htm

Check out the given link for this company profile on Linkedin: https://www.linkedin.com/company/dunnhumby/?originalSubdomain=in

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