Universally Unique Identifier (UUID)
An Universally Unique Identifier (UUID) is a 128-bit unique identifier that follows a UUID scheme.
- AKA: Globally Unique Identifier (GUID).
- Example(s):
123e4567-e89b-12d3-a456-426655440000
- See: Numbering Scheme, Hash Collision, Canonical Form, Hexadecimal.
References
2017
- (Wikipedia, 2017) ⇒ https://en.wikipedia.org/wiki/Universally_unique_identifier Retrieved:2017-11-3.
- A universally unique identifier (UUID) is a 128-bit number used to identify information in computer systems. The term globally unique identifier (GUID) is also used.
When generated according to the standard methods, UUIDs are for practical purposes unique, without depending for their uniqueness on a central registration authority or coordination between the parties generating them, unlike most other numbering schemes. While the probability that a UUID will be duplicated is not zero, it is close enough to zero to be negligible.
Thus, anyone can create a UUID and use it to identify something with near certainty that the identifier does not duplicate one that has already been, or will be, created to identify something else. Information labeled with UUIDs by independent parties can therefore be later combined into a single database, or transmitted on the same channel, without needing to resolve conflicts between identifiers.
Adoption of UUIDs and GUIDs is widespread, with many computing platforms providing support for generating them, and for parsing their textual representation.
- A universally unique identifier (UUID) is a 128-bit number used to identify information in computer systems. The term globally unique identifier (GUID) is also used.
2016
- (Wikipedia, 2016) ⇒ https://en.wikipedia.org/wiki/Universally_unique_identifier Retrieved:2016-9-7.
- A universally unique identifier (UUID) is an identifier standard used in software construction. A UUID is simply a 128-bit value. The meaning of each bit is defined by any of several variants.
For human-readable display, many systems use a canonical format using hexadecimal text with inserted hyphen characters. For example:
:
123e4567-e89b-12d3-a456-426655440000The intent of UUIDs is to enable distributed systems to uniquely identify information without significant central coordination. In this context the word unique should be taken to mean "practically unique" rather than "guaranteed unique". Since the identifiers have a finite size, it is possible for two differing items to share the same identifier. This is a form of hash collision. The identifier size and generation process need to be selected so as to make this sufficiently improbable in practice. Anyone can create a UUID and use it to identify something with reasonable confidence that the same identifier will never be unintentionally created by anyone to identify something else. Information labeled with UUIDs can therefore be later combined into a single database without needing to resolve identifier (ID) conflicts.
Adoption of UUIDs is widespread with many computing platforms providing support for generating UUIDs and for parsing/generating their textual representation.
- A universally unique identifier (UUID) is an identifier standard used in software construction. A UUID is simply a 128-bit value. The meaning of each bit is defined by any of several variants.
2005
- https://tools.ietf.org/html/rfc4122.html
- QUOTE: This specification defines a Uniform Resource Name namespace for UUIDs (Universally Unique IDentifier), also known as GUIDs (Globally Unique IDentifier). A UUID is 128 bits long, and can guarantee uniqueness across space and time.