What is partitioning and sharding? Have you used them?

Partitioning and sharding are methods of data separation for system scaling.

Partitioning is a logical division of data within a single system or database into parts (partitions) based on a certain attribute (for example, by date or key). This allows for faster queries and easier data management.

Sharding is a broader term that refers to horizontal division of data across multiple independent servers or nodes (shards). Each shard contains a part of the data and operates as a separate unit. This enables horizontal scaling of the system.

In practice, sharding is often implemented through partitioning with distribution of partitions across different servers.

Example of use: in a distributed database or cache system, user data is divided by a shard key (for example, user_id % number of shards) so that queries can be processed in parallel and the load is distributed.

// Example of simple sharding by userID
func getShard(userID int, shardCount int) int {
    return userID % shardCount
}

shard := getShard(12345, 10) // Determine which shard the user will fall into

This approach helps to scale applications and databases.