UUID/GUID v7

dotNet 9 introduce a new type of GUID called UUIDv7. This is like a regular GUID struct (of type UUIDv4) which attempts to be as random as possible, but this can cause fragmentation in some databases when used as a key.

With UUIDv7 the first few bytes (the first two segments) are replace with time related (timestamp) data, which solves this problem, allows for sorting by ID, etc.

This is created via the method:

Guid.CreateVersion7();