The Problem with Using a UUID Primary Key in MySQL

This post details the performance implications of using UUIDs as primary keys in MySQL, contrasting them with auto-incrementing integers. It explains how random UUIDs can lead to B+ Tree page splitting and fragmentation, negatively impacting insert performance and storage utilization. The post recommends using the `BINARY(16)` data type for UUIDs, opting for ordered UUID variants (v6, v7), and utilizing MySQL's `UUID_TO_BIN` function with the 'swap flag'. It also suggests alternative ID types like Snowflake IDs, ULIDs, and NanoIDs, and references PlanetScale's use of NanoIDs for its API.