I'm using this only to convert string to something (using `PostgreSQLColumn`).
In that case, I'm not trying to validate or insert/update in the database.

If the limit is higher, then it's a text field and the OID is `1009` 

I could have used `execute("SELECT format_type(res.ftype(i), res.fmod(i))").first["format_type"]` but it will fire another query for each column :-/