Interview Questions

Explain the use of Elastic Resize vs. Classic Resize in Redshift.

Explain the use of surrogate keys vs. natural keys in data modeling.

Explain types of joins in Spark with examples.

Explain your approach to optimizing a slow-running query on a table with billions of rows.

Explain your understanding of indexing, partitioning, and execution plans.

Fact vs Dimension Table - categorize data

Facts and Dimension Tables Properties

Features of NoSQL Databases

Filter Rows Where Employee Salary > Manager Salary

Find 3rd Highest Salary

Find Employees with Maximum Salary in Each Department

Find average salary by department, max average salary, and list of employees for the max salary department.

Find average salary for each manager – Assume a table with manager_id and employee_salary

Find each student's previous year's scores using the LAG function.

Find employees who earn the third-highest salary.

Find non-common records in two tables (SQL EXCEPT or NOT IN)

Find the 2nd highest salary for each department using the DENSE_RANK() function.

Find the error in the provided SQL query.

Find the second-highest salary in the employees table using three different methods.

Find the third-highest salary for each department.