UUIDs are commonly used as primary keys in database tables due to their easy generation, sharing between systems, and guaranteed uniqueness. This article focuses on efficiently using UUIDs as primary keys in PostgreSQL. Storing UUIDs as strings using the text data type is not optimal, as PostgreSQL has a dedicated uuid data type which takes up less space. An experiment comparing tables with text vs uuid primary keys showed significant differences in size, with uuid being more efficient. Using UUID v7, a time-sorted value, can improve insert performance compared to regular UUID v4. While UUIDs may not be the best choice for primary keys, optimizations can make a difference in handling large datasets and high traffic.
https://maciejwalkowiak.com/blog/postgres-uuid-primary-key/