Question 1

What is UUID v6?

Accepted Answer

UUID v6 is a time-ordered universally unique identifier defined in RFC 9562. It improves upon UUID v1 by reordering timestamp fields for better lexicographic sorting, making it ideal for database indexes and distributed systems where chronological ordering matters.

Question 2

When should I use UUID v6?

Accepted Answer

Use UUID v6 when you need time-ordered identifiers with good database performance. Perfect for database primary keys, distributed system logs, event tracking, and any scenario where sorting by creation time is important. It's especially useful when migrating from UUID v1 systems.

Question 3

What's the difference between UUID v6 and v4?

Accepted Answer

UUID v4 is completely random with no inherent ordering, while UUID v6 is time-ordered and sortable. V6 contains a timestamp, making sequential UUIDs sort chronologically. V4 is better for security-sensitive scenarios, while v6 is better for database performance and time-based queries.

Question 4

Is UUID v6 better than UUID v1?

Accepted Answer

Yes, UUID v6 improves upon v1 by reordering the timestamp bits for better lexicographic sorting. This results in better database index performance and more efficient storage. Both contain timestamps and MAC addresses, but v6's layout is optimized for modern database systems.

Version	Time-based	Sortable	Best Use Case
v1			Legacy systems
v4			Random IDs, security
v6			Modern databases
v7			Latest standard (2024)

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