Can you explain what sharding means in the context of databases?

Sharding is a method of horizontal scaling of a database, where data is divided into parts (shards), each stored on a separate server or cluster.

The main idea is to distribute the load and data volume across multiple machines, improving performance and availability.

For example, if you have a user table, you can split users by the first letter of their last name: users with last names A–F in one shard, G–L in the second, and so on.

Advantages of sharding:

• Reduces load on a single server
• Allows scaling the system as data grows
• Increases fault tolerance

However, sharding complicates architecture, requires a well-thought-out request routing mechanism, and can make executing complex queries that involve multiple shards more difficult.