JavaScript is required to use this application. Please enable JavaScript in your browser settings or disable any extensions that may be blocking scripts.
Interview questions · medium
Write an SQL query to find the second-highest salary from an employee table.
What is the difference between cache() and persist() in Spark? When would you use each?
What is the difference between groupByKey and reduceByKey in Spark?
Discuss differences between ROW_NUMBER(), RANK(), and DENSE_RANK(), and provide examples from your projects.
Can you explain the difference between OLTP and OLAP?
Describe a time when you had to optimize a slow SQL query. What steps did you take?
Explain the difference between INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.
How do you handle NULL values in SQL? Mention functions like COALESCE and NULLIF.
Get the complete 1,800+ question library with detailed, expert-level answers covering SQL, Spark, System Design, Python, Cloud, and Behavioral topics.