UUID Best Practices for Modern Applications
Working with UUIDs requires understanding not just how to generate them, but how to use them effectively in real-world applications. This guide covers industry-proven patterns and common pitfalls.
1. Choose the Right UUID Version
Use UUID v7 for database primary keys (sortable, good index performance). Use UUID v4 for security tokens and session IDs (maximum randomness). Use UUID v5 when you need deterministic IDs from input data.
2. Store UUIDs Efficiently
In PostgreSQL, use the native UUID type. In MySQL 8+, use BINARY(16) with BIN_TO_UUID/UUID_TO_BIN functions. Never store UUIDs as VARCHAR(36) - it wastes space and hurts performance.
3. Index Strategy
For UUID primary keys, always use clustered indexes. With UUID v7, inserts naturally maintain order. With UUID v4, consider using composite indexes or secondary sequential columns for range queries.
4. API Design Patterns
Always accept UUIDs in both hyphenated and non-hyphenated formats. Validate UUID format on input. Return UUIDs in lowercase hyphenated format for consistency. Never expose internal auto-increment IDs in APIs.
5. Testing and Debugging
Use predictable UUIDs in tests (e.g., 00000000-0000-0000-0000-000000000001). Add UUID formatting helpers to your logging. Consider storing creation timestamp separately for debugging even with UUID v7.
Conclusion
Following these best practices will help you build robust, scalable applications. Remember that UUID choice depends on your specific use case - there's no one-size-fits-all solution.
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