How does it compare with UUID v7 (C# GUID.CreateVersion7())

[brmassa]

I might be wrong, but from what I understand for the new UUID v7, the initial statements, only the first still true:

• It isn't the most character efficient way of encoding 128 bits of randomness: no big change here
• UUID v1/v2 is impractical in many environments, as it requires access to a unique, stable MAC address: v7 not not use MAC
• UUID v3/v5 requires a unique seed and produces randomly distributed IDs, which can cause fragmentation in many data structures: UUIDv7 does not require it
• UUID v4 provides no other information than randomness which can cause fragmentation in many data structures v7 includes a timestamp

I don't know the performance benchmarks.

[neuecc]

In my personal opinion, I think it's best to use GUID.CreateVersion7() preferentially in .NET 9 and later.
There are problems with Ulid in terms of interoperability with Guid, and UUIDv7, which works with Guid, is personally the most ideal ID.
In terms of performance, the current implementation of CreateVersion7 is inferior to NewGuid because it generates a Guid and then fills in the Timestamp part.
However, this is probably not something to worry about.