MATRIX Resources Software Developer interview questions

Hi, This is from an interview for a BI report developer position at Matrix. 1. What is denormalization, when and why would we use it? 2. List all the types of join and explain. 3. Explain: Star schema, snowflake, and the difference between OLTP and OLAP. 4. What is a Clustered Index and when would we use it? 5. Why wouldn't we want to implement foreign keys in fact. 6. What is a type 2 slow variable, list 2 types of SCD. 7. What is the difference between a unique key and a primary key. SQL questions: 1. Name, subject, and grade table. Output: Which students got 100 in both math and physics. 2. Display the second maximum in the table. Programming questions: 1. When the number is a multiple of 3, print something, when the number is a multiple of 7, print something, and when it is a multiple of 3 and 7, print something else. 2. Display the 2 largest numbers in the array.