Redis

Redis is an in-memory data store that stores data in RAM, allowing applications to access it very quickly.

Think of Redis as a super-fast storage space that your application can use to avoid repeatedly fetching the same data from a slower database.

Simple example

Imagine you have a website with 10,000 users visiting the same page.

Without Redis:

1. Every request fetches data from a database.
2. The database does repeated work.
3. Responses may become slower.

With Redis:

1. The application fetches the data from the database once.
2. It stores the result in Redis.
3. Later requests read the result from Redis, which is usually much faster.

What is Redis used for?

• Caching: Store frequently accessed data.
• Session management: Remember that a user is logged in.
• Rate limiting: Restrict how many requests a user can make.
• Real-time leaderboards: Maintain game scores and rankings.
• Message queues: Help applications exchange messages.

How does Redis work?

Redis stores data as key-value pairs.

SET username "Rahul"
GET username

Here, SET stores the value and GET retrieves it.

Redis also supports data structures such as lists, sets, hashes, sorted sets, and streams.

Redis vs. a traditional database