Database Sharding Techniques

As a SaaS application grows, a single database often becomes a bottleneck. Traditional scaling, known as vertical scaling, involves upgrading to a more powerful server (more CPU, RAM, storage).

However, vertical scaling has limits and can become very expensive. For SaaS, which serves many tenants, we need a way to scale our data horizontally across multiple database instances.

Database sharding is a technique to horizontally partition data across multiple database instances. Think of it like splitting a very large book into several smaller books, each stored on a different shelf.

• Each 'smaller book' is called a shard.
• Each shard is a complete database instance, holding a subset of the total data.
• Together, these shards form the complete logical database.

Sharding helps distribute load, improve performance, and manage massive datasets for SaaS.