sharding

Go beyond a single database: learn how read replicas offload query load, how range and hash sharding partition data, why consistent hashing makes rebalancing tractable, and how to pick a shard key that avoids the celebrity problem and cross-shard pain.

How do you scale a database beyond one machine while keeping it reliable? This lesson covers every major replication topology, the quorum math behind leaderless systems, and partitioning strategies from range keys to consistent hashing — including how to avoid hot partitions and handle rebalancing.

When one database isn't enough. How sharding splits data across nodes, the trade-offs of different sharding keys, and the operational headaches (hot spots, rebalancing, cross-shard queries) you sign up for.