Introduction to UUID v7 in .NET 9

• Presenter: Nick
• Focus: New type of ID in .NET 9 intended to replace GUIDs and integers in database scenarios.

GUIDs and Their Limitations

• GUID (Globally Unique Identifier) and its issues in relational databases.
• Performance problems when used as primary keys.
• Typically default to auto-incremented integers for better performance, which has its own set of challenges.

Introducing UUID v7

• New ID type: UUID version 7 (UUIDv7).
• Builds on existing knowledge of GUIDs but addresses performance issues.

Differences from GUID

• GUID generally refers to UUID version 4 (UUIDv4).
• UUIDv4 generates random values and is designed to minimize clashes but lacks order.
• UUIDv7 uses Unix timestamp for order, solving database performance problems.

Implementation in C#

• Creating a GUID in C#: Guid new Guid();
• To create UUIDv7 in .NET 9: Guid create version 7; this will utilize the same method as GUID but incorporate the time component.
• Supports passing DateTimeOffset to set the timestamp:

  timeProvider: system.getUTCTimeNow();
  

• UUIDv7 is structured such that the first bits are time-stamped establishing ordering.

Performance Consideration

• Comparison of UUIDv4 and UUIDv7 generation times:
  • UUIDv4: 37 nanoseconds
  • UUIDv7: 70 nanoseconds
• UUIDv7 takes longer to generate (~40 nanoseconds slower) but has no memory allocation difference.
• Despite a performance hit, the advantages of using UUIDv7 outweigh this delay, particularly for database keys.

Advantages of Using UUIDv7

• More efficient in modern database systems where order and uniqueness are conflicting requirements.
• Should not replace existing UUIDs in existing systems without due consideration of clashes but can be beneficial for new systems.
• Flawlessly integrates into existing applications due to its mapping back to the GUID type.

Additional Information

• Current promotions on courses related to this topic, including OpenTelemetry.

Conclusion

• Call to action: Share thoughts and experiences regarding ID types in the comments.
• Reminder to keep coding!

---