[glancast]

For those (like me) who are wary of enums, it's very simple to create a tiny table with one column of distinct string values. Future-proof and serves the same function if you add not-null foreign key constraints to your dependent tables.

[jdfellow]

I may be mistaken, but I believe under the hood Postgres enums work in a very similar way to this, only the strings are interred instead of duplicated across your tables.

[glancast]

Yes, that's true. I'm paying the small duplication cost in exchange for removing enums' cumbersome limitations. Not saying I never use them, but I usually end up regretting it when I do :)