UUIDs in Practice — When Auto-Increment Falls Short

Most of us learned databases with auto-increment IDs. id INT AUTO_INCREMENT is in every tutorial. It works — until it doesn't.

The Case for Auto-Increment

Auto-increment integers are fast, small (4 bytes), and naturally ordered. For a single-database app with one writer, they're perfect. But real systems rarely stay that simple.

Where Auto-Increment Fails

Distributed writes. When you have multiple API servers writing to the same database, auto-increment creates a bottleneck. Someone has to own the counter.