What is database scaling?

Database scaling is the process of increasing a database system's ability to handle more data, queries, writes, or concurrent users while maintaining acceptable performance and reliability.

Scaling can include larger hardware, read replicas, partitioning, sharding, caching, query optimization, connection management, and separating workloads. The correct approach depends on whether the bottleneck is CPU, memory, I/O, locks, connections, storage, or a particular query pattern.