Kirill Reshke <reshkekirill(at)gmail(dot)com> writes:
> If a user creates a malformed operator in theirs database, like:
> ...
> then psql's meta-commands queries like \du stop working.
Yup.
> I think this can be enhanced a little by schema-qualifying psql's
> internal query.
This has been discussed and rejected before. Fully schema-qualifying
those queries would make them unreadable and close to unmaintainable.
And before you say that readability doesn't matter here: you're wrong.
Lots of people look at these queries via "psql -E" to see how to query
the catalogs.
regards, tom lane