Sharding

Sharding horizontally partitions data across multiple databases to improve scalability and performance.

What is Sharding?

Sharding is a database architecture pattern that horizontally partitions data across multiple independent databases (shards), each containing a subset of the total data.

Sharding considerations

Shard key selection, Cross-shard queries, Rebalancing, Operational complexity.

Common misconceptions

"Sharding solves all scaling" — Adds significant complexity
"Any column works as shard key" — Critical design decision
"Sharding is easy to undo" — Difficult architectural change