Data Engineering Analyst Interview Questions and Answers for Freshers

The problem requires returning an array where each element is the product of all elements in the input array except itself.

• Iterate through the array twice to calculate the product of all elements to the left and right of each element.

• Use two arrays to store the products of elements to the left and right of each element.

• Multiply the corresponding elements from the left and right arrays to get the final product array.

• Handle integer overflow by taking modulo MOD = 10^9 + 7.

• To so...read more

Find the maximum sum of a contiguous subarray within an array of integers.

• Use Kadane's algorithm to find the maximum subarray sum efficiently.

• Initialize two variables: max_sum and current_sum.

• Iterate through the array and update current_sum and max_sum accordingly.

• Return the max_sum as the result.

Window analytical functions are used to perform calculations across a set of table rows related to the current row.

• Window functions operate on a set of rows related to the current row

• They allow calculations to be performed across a group of rows

• Common window functions include ROW_NUMBER(), RANK(), DENSE_RANK(), and NTILE()

• They are used with the OVER() clause in SQL queries

Use SQL query with ORDER BY and LIMIT to find nth highest salary.

• Use ORDER BY clause to sort salaries in descending order

• Use LIMIT to specify the nth highest salary

• Example: SELECT salary FROM employees ORDER BY salary DESC LIMIT n-1, 1