Why use UUIDs for database primary keys?

UUIDs (Universally Unique Identifiers) are excellent for database primary keys for several reasons. Our uuid generator creates unique id generator values that are: 1) Globally unique across distributed systems, 2) Not sequential (unlike auto-increment IDs), which prevents ID guessing attacks, 3) Merge-friendly — you can combine data from different databases without ID collisions, and 4) Created offline without database round-trips. Use the random uuid v4 for most cases, or the uuid4 generator for cryptographically secure values. The guid generator (Microsoft's version) is equally valid. For time-sortable IDs, use UUID v7 from our online uuid generator. However, note that UUIDs use more storage (16 bytes vs 4-8 bytes for integers) and may slightly impact index performance. Consider uuid generator for distributed systems or when you need IDs that are meaningful across multiple services.