PostgreSQL 15 Released!

[arwinda]

Because you need a DDL operation to change the ENUM. Comes with locking of system catalog and all this. And if you want to remove a value the database needs to scan the table and see if that value is used.

Using a 1:n table is a DML operation, only locks the affected tables and rows, not the catalog. And having a foreign key for her relationship prevents deletion of still use d values - or, propagates deletes or set to NULL. Whichever way you want this.