| Identifier | Pros | Cons | Best for | |------------|------|------|----------| | Auto-increment INT | Small, fast, sortable | Not globally unique, exposes count | Single-server, internal tables | | Snowflake ID (Twitter) | 64-bit, time-ordered, distributed | Requires coordination (worker ID) | High-throughput distributed systems | | ULID | Lexicographically sortable, 26 chars | Not standard RFC, less library support | Modern applications that want readability | | UUID v4 | Standard, offline generation, widespread | Random, poor index locality | Anywhere you need global uniqueness | | UUID v7 | Time-ordered + random | Newer, less legacy support | Future-proof work systems |
No human can memorize 4bce6bec-d94b-bdc9-8531-5f0fac3a084c . For support tickets, use short codes or a separate "reference number" column. Developers copy-paste UUIDs; they do not type them. 4bce6bec-d94b-bdc9-8531-5f0fac3a084c WORK
RESTful APIs often use UUIDs in URLs:
Thus, despite the version nibble issue, the format is UUID-like. | Identifier | Pros | Cons | Best