Database sharding is a technique used to horizontally scale a database by splitting (or partitioning) large datasets into smaller, faster, and more manageable parts called shards.

Each shard is an independent database that holds a subset of the overall data. Together, all the shards make up the complete dataset.

How It Works:

• Instead of storing all your data in one huge table in one database,
• You split the data across multiple databases or servers,
• Usually based on a sharding key (e.g., user_id, region, order_id).

For example:

User ID	Shard Location
1–1000	Database A
1001–2000	Database B
2001–3000	Database C

Benefits of Sharding

• Scalability: Each shard can be hosted on a different server, allowing horizontal scaling.
• Performance: Smaller datasets in each shard lead to faster queries.
• Availability: Even if one shard fails, others can continue to operate.