Answers

1. In MySQL, what is difference between BTREE and HASH indices?
2. What are differences between COUNT(*), COUNT(1) and COUNT(column_name)?
3. Explain the different types of SQL commands.
4. Explain the different types of JOIN.
5. What’s the difference between a WHERE clause and a HAVING clause?
6. What’s the difference between a TRUNCATE command and a DELETE command?
7. What are UNION, UNION ALL, MINUS, and INTERSECT set operators?
8. What are Normalization and Denormalization?
9. What are scalar functions?
10. What are aggregate functions?
11. What is a stored procedure?
12. What is an index?
13. What is an SQL Server cursor? How do you use it?
14. What are the different types of indexes?
15. What are ACID properties?
16. What is a schema?
17. What is an alias command?
18. What is the difference between CHAR and VARCHAR datatypes in SQL?
19. What is collation? What are the different collation sensitivity?

1. Provide an integer n and a list of integers nums, find all pairs of integer which are sum equal to n. Pairs are unique, (x,y) and (y,x) are one result.
   • Python
2. Find the Longest Increasing Odds Subsequence
   • Python

1. How many people come out of an airport everyday?