Can you explain the main types of database sharding?

Sharding is a method of horizontally partitioning a database into parts (shards) to improve scalability and performance. The main types of sharding:

1. Range Sharding — data is divided by ranges of key values. For example, users with IDs from 1 to 10,000 in one shard, from 10,001 to 20,000 in another.

2. Hash Sharding — keys are processed through a hash function, and the result determines which shard the data will go to. This distributes the load evenly.

3. List Sharding — data is distributed according to predefined lists of key values. For example, users from different countries are stored in different shards.

4. Geographical Sharding — data is divided based on geographic location, which is useful for localization and reducing latency.

Each method is chosen depending on the nature of the data and system requirements.