GfK MODE Interview Questions and Answers

Coalesce is a function used to return the first non-null value in a list of expressions.

• Coalesce function is commonly used in SQL to handle null values.

• It takes multiple arguments and returns the first non-null value.

• Example: COALESCE(column1, column2, 'default') will return the value of column1 if not null, else column2, and if both are null, it will return 'default'.

Repartition is the process of redistributing data across partitions in a distributed system.

• Repartitioning helps in balancing the workload and improving performance in distributed computing environments.

• It involves moving data between partitions based on certain criteria such as key values or hash functions.

• Repartitioning can be done in Spark using operations like repartition() or coalesce().

Yes, I make sure to thoroughly read and understand all company policies.

• I believe it is important to read and understand company policies to ensure compliance and avoid any misunderstandings.

• Reading company policies helps me stay informed about the rules and regulations within the organization.

• I make it a priority to review and familiarize myself with all policies to ensure I am following the correct procedures.

• For example, in my previous role, I always made sure to read the ...read more

A non repeatable character is a character that appears only once in a given string.

• Iterate through the string and count the frequency of each character

• Identify the characters that have a frequency of 1

• Return the first non repeatable character found

Sort list without using sort method

• Create a custom sorting function using loops

• Compare each element with every other element to determine the correct order

• Swap elements based on the comparison results

SQL is a programming language used for managing and manipulating relational databases. Excel formulas are used for performing calculations and data analysis in Microsoft Excel.

• SQL is used to retrieve, insert, update, and delete data from databases.

• Excel formulas are written using functions and operators to perform calculations and manipulate data.

• SQL example: SELECT * FROM customers WHERE age > 30;

• Excel formula example: =SUM(A1:A10) calculates the sum of values in cells A1 to...read more