Advarra Research Consultant Interview Questions and Answers

n-tier architecture is a software design pattern that divides an application into logical layers.

• It separates presentation, application processing, and data management functions.

• Each layer can be developed and maintained independently.

• Examples include 3-tier and 4-tier architectures.

• It improves scalability, maintainability, and flexibility of the application.

Use SQL query to fetch maximum and minimum salary from emp table

• Use SELECT MAX(salary) FROM emp to fetch maximum salary

• Use SELECT MIN(salary) FROM emp to fetch minimum salary

Indexes and exceptions are used to optimize database performance and handle errors in code.

• Indexes are used to quickly retrieve data from a database by creating a sorted list of values.

• Exceptions are used to handle errors in code and prevent the program from crashing.

• Examples: Creating indexes on frequently queried columns like 'id' or 'timestamp'. Using try-catch blocks to handle exceptions like divide by zero.