TiKV 101: What Is TiKV?

TiKV is the storage layer of TiDB, a distributed SQL database.

A database stores and manages data. Almost every online service, from shopping websites to banking systems, depends on databases to keep track of information.

A distributed database spreads data across multiple machines so the system can grow beyond a single machine, handle higher traffic, and keep working through machine failures.

TiDB is one such distributed database. TiKV is the storage layer inside TiDB: the component responsible for storing and retrieving data.

At its core, TiKV is a highly scalable, low-latency key-value store. A key-value store organizes data as pairs: given a key, the system stores or retrieves the corresponding value.

key                 value
-----------------   -----
user:42:name        Alice
user:42:city        Shanghai
order:9001:status   paid

Real TiKV is much more complex than this, but this key-value model is the first mental model to keep in mind.

Low latency means TiKV is designed to serve reads and writes quickly. Another important part of TiKV is transaction support: when one logical operation touches multiple pieces of data, those changes must be applied correctly together.

These properties are essential for OLTP (Online Transaction Processing) workloads, which power user-facing applications such as creating an order, updating an account balance, or changing a user profile. These operations are usually small, but they require both low latency and strong correctness.

This combination is what makes TiKV interesting. It is not just a place to store data. It is a distributed system designed to remain fast and reliable as data grows, traffic increases, and failures become inevitable.