037 | Databases in Detail: Redis — A High-Speed Key-Value Store and Cache

29.06.2025

We’ve already explored relational databases (MySQL, PostgreSQL, SQLite), which are great for structured data and complex queries. Now we move into the world of NoSQL, starting with one of its brightest stars — Redis (Remote Dictionary Server). Redis is an incredibly fast and versatile server often described as a “data structure server on steroids.”

What is Redis?

Redis is a free and open-source (BSD licensed) NoSQL key-value database that stores data in memory (in-memory). Unlike traditional disk-based databases, Redis is designed to deliver maximum data access speed. While it’s a key-value store, Redis stands out because the values can be not only strings but also rich data structures like strings, lists, sets, hashes, sorted sets with scores, bitmaps, and hyperloglogs.