What types of sharding exist? Describe the main approaches.

Sharding is a method of horizontally partitioning data into parts (shards) to scale and improve performance.

Main types and approaches of sharding:

• Range Sharding: data is divided into shards based on key ranges. For example, users with IDs from 1 to 1000 are in one shard, from 1001 to 2000 in another.
• Hash Sharding: keys are passed through a hash function, the result of which determines the shard. It ensures even distribution of load.
• List Sharding: data is distributed according to lists of key values, such as by countries or categories.
• Geographical Sharding: data is divided by regions to localize and reduce latency.

The choice of approach depends on the nature of the data and requirements for load, consistency, and scalability.