Databases & Data Storage

Key-Value Store

Definition

A key-value store, or key-value database, is a simple database that uses a simple key/value method to store data. A key-value database stores data as a collection of key-value pairs in which a key serves as a unique identifier.

Why It Matters

Key-value stores are incredibly simple and incredibly fast. They are ideal for use cases that require very high-speed data retrieval for a known key, such as caching, session management, and real-time leaderboards.

Contextual Example

A website stores user session information in Redis, a popular key-value store. The session ID is the key, and the user's information is the value. When the user makes a request, the website can quickly retrieve their session data from Redis using the session ID.

Common Misunderstandings

  • Key-value stores are the simplest type of NoSQL database.
  • They do not typically support complex queries or relationships. You can only retrieve a value if you know its exact key.

Related Terms

Last Updated: December 17, 2025