C#•11mo ago

Is there a standard option to generate UUID version 7? (Guid)

Hello, .NET provides a way to generate UUID v4 with Guid.NewGuid(), but this cannot be used as a PK for tables. In Postgres newer UUID versions can be used as primary keys, as they are sortable and because of that there is no index fragmentation. Is there a standard library that is used for generating UUID 7? It is a bit odd there is no built in way to do this.

4 Replies

jcotton42•11mo ago

are you looking specifically for a database scenario? b/c usually you'd want the database to do that work but to answer your question directly, afaik no

Kiel•11mo ago

I use https://github.com/medo64/Medo.Uuid7 - it has efcore integration to take care of all the conversion stuff i believe

GitHub

GitHub - medo64/Medo.Uuid7: This is a C# implementation of UUIDv7 g...

This is a C# implementation of UUIDv7 generation algorithm. - GitHub - medo64/Medo.Uuid7: This is a C# implementation of UUIDv7 generation algorithm.

Kiel•11mo ago

it's not available in the BCL yet and probably won't be for awhile if ever just to avoid confusion over multiple potentially conflicting UUID types

CoreOP•11mo ago

Thanks, after doing a bit of research, it turns out that the UUID 7 is still in development: https://uuid.ramsey.dev/en/stable/rfc4122/version7.html It will take time until this is standardized

 Method    | Mean     | Error    | StdDev   | Ratio | RatioSD | Rank | Gen0   | Allocated | Alloc Ratio |
|---------- |---------:|---------:|---------:|------:|--------:|-----:|-------:|----------:|------------:|
| NewGuid   | 35.43 ns | 0.177 ns | 0.148 ns |  1.00 |    0.00 |    1 |      - |         - |          NA |
| MedoUuid7 | 47.74 ns | 0.474 ns | 0.582 ns |  1.35 |    0.02 |    2 | 0.0032 |      40 B |          NA |
| UUIDNext  | 93.51 ns | 0.859 ns | 0.804 ns |  2.64 |    0.02 |    3 |      - |         - |          NA |

 Method    | Mean     | Error    | StdDev   | Ratio | RatioSD | Rank | Gen0   | Allocated | Alloc Ratio |
|---------- |---------:|---------:|---------:|------:|--------:|-----:|-------:|----------:|------------:|
| NewGuid   | 35.43 ns | 0.177 ns | 0.148 ns |  1.00 |    0.00 |    1 |      - |         - |          NA |
| MedoUuid7 | 47.74 ns | 0.474 ns | 0.582 ns |  1.35 |    0.02 |    2 | 0.0032 |      40 B |          NA |
| UUIDNext  | 93.51 ns | 0.859 ns | 0.804 ns |  2.64 |    0.02 |    3 |      - |         - |          NA |

The speed of the generations is not much worse compared to the Guid.NewGuid() I will go with the Medo.Uuid7, thank you for the suggestion Isn't it a bit concerning that it allocates 40B memory?

Gaming

Programming

Is there a standard option to generate UUID version 7? (Guid)