UUID · ffffffff-ffff-ffff-ffff-ffffffffffff
Max UUID
ffffffff-ffff-ffff-ffff-ffffffffffff, the all-one UUID.
Key facts
| Value | ffffffff-ffff-ffff-ffff-ffffffffffff |
|---|---|
| Meaning | Sentinel upper bound |
| Version | None |
| Introduced | RFC 9562 |
| Use | Range bounds and tests |
Where it is useful
The max UUID gives tests and range queries a well-defined upper bound when the key type is UUID. Like nil, it is a marker rather than an identifier. Storing it as a real key invites the same confusion as storing nil.
Comparing values
Compare UUIDs as bytes or in canonical text order. The max value sorts after every valid versioned UUID, which makes it a convenient exclusive upper bound in lexicographic queries.
Frequently asked questions
Is max UUID generated randomly?
No. It is a fixed sentinel value.
Is it the same as a v4 with all bits set?
No. A real v4 has fixed version and variant bits, so it can never be all ones.
Does it sort last?
Yes in canonical hex order, after all normal UUID values.