What is a UUID (GUID)?
What is a UUID (GUID)?
UUID stands for Universally Unique Identifier (sometimes called “GUID” or “Globally Unique Identifiers”). UUIDs are 36 character strings containing numbers, letters and dashes. UUIDs are designed to be globally unique. There are several UUID versions with slightly different purposes.
Is it safe to merge UUIDs?
The chances of a duplicate UUID are so low it is safe to assume each ID will be unique. Separate computers can generate UUIDs at the same time with no communication and still be confident the UUIDs are unique. Independent systems that use UUIDs can be safely merged at any time without worrying about collisions.
What is the UUID variant 2 (Leach-Salz) UUID?
The layout of a variant 2 (Leach-Salz) UUID is as follows: The most significant long consists of the following unsigned fields: The variant field contains a value which identifies the layout of the UUID. The bit layout described above is valid only for a UUID with a variant value of 2, which indicates the Leach-Salz variant.
When to use time-based UUIDs?
Most of the time, the MAC address of the main network interface of the host is used as a unique identifier. There are important points to consider when you use time-based UUID values: It is possible to determine the approximated time when the value was generated from the first 3 fields
