Kellton Interview Questions and Answers

select_related follows foreign key relationships and retrieves related objects in a single query, while prefetch_related retrieves related objects separately to avoid performance issues.

• select_related is used for accessing related objects in a single query, reducing database hits

• prefetch_related is used for accessing related objects separately to avoid performance issues

• select_related is more efficient for one-to-one o...read more

Decorator is a design pattern in software development that allows behavior to be added to individual objects, either statically or dynamically.

• Decorators are used to modify the behavior of functions or classes without changing their source code.

• In Python, decorators are implemented using the @ symbol followed by the decorator function name.

• Example: @decorator_function def some_function(): # function implementation

• ...read more

Optimizing query involves indexing, minimizing data retrieval, using proper joins, and avoiding unnecessary functions.

• Use indexes on columns frequently used in WHERE clauses

• Minimize data retrieval by selecting only necessary columns

• Use proper joins (INNER JOIN, LEFT JOIN, etc.) instead of subqueries

• Avoid unnecessary functions in WHERE clauses

Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.

• Normalization is used to eliminate redundant data and ensure data dependencies are logical.

• It involves dividing a database into two or more tables and defining relationships between them.

• Normalization helps in reducing data redundancy, improving data integrity, and making data maintenance easier.

• There are diffe...read more

To increase performance, optimize code, use efficient algorithms, parallel processing, caching, and database indexing.

• Optimize code by reducing unnecessary loops and improving data structures

• Use efficient algorithms like binary search instead of linear search

• Implement parallel processing to utilize multiple CPU cores

• Utilize caching to store frequently accessed data for faster retrieval

• Implement database indexing to spe...read more

Securing APIs involves using authentication, authorization, encryption, and monitoring.

• Implement authentication mechanisms such as OAuth, JWT, or API keys to verify the identity of clients accessing the API.

• Use authorization to control access to different parts of the API based on roles and permissions.

• Encrypt data transmitted between clients and the API using HTTPS to prevent eavesdropping.

• Implement rate limiting and ...read more

Single design patterns work by providing a reusable solution to common problems in software development.

• Design patterns help in organizing code and making it more maintainable.

• They promote code reusability and flexibility.

• Examples of single design patterns include Singleton, Factory, and Observer.