I was surprised to see that both json and jsonb columns in postgres are mapped as T.untyped despite having popular usage. I couldn't find any discussions about this when searching the issues.

json => ActiveRecord::Type::Json
jsonb => ActiveRecord::ConnectionAdapters::PostgreSQL::OID::Jsonb

Question for maintainers: Are there any known gotchas for implementing this in a straightforward way compared to other types? I have some concerns here because it seems like if it isn't implemented there was a good reason for that, but I couldn't find a mention of that anywhere.