A UUID (Universally Unique Identifier) is a 128-bit value used to generate identifiers that are extremely unlikely to collide. UUIDs are represented as 32 hexadecimal characters in a standardized format. Unlike auto-incrementing IDs, UUIDs can be generated independently across distributed systems without coordination, making them ideal for scalable architectures.
Why it matters
UUIDs avoid contention in distributed databases and simplify replication and sharding. They enhance security by making identifiers harder to guess compared to sequential integers. However, UUIDs are larger and slower to index, which can affect database performance.
Examples
Using a UUID as a primary key for users in a microservices architecture or generating unique file names for object storage uploads. Lessons covering database schema design reference UUID tradeoffs.