David Rowley <dgrowleyml(at)gmail(dot)com> writes:
> Can you share which version of PostgreSQL you see this on?
Hmm ... looking more closely, it's definitely not stock PG,
because proargtypes is oidvector which would not include any
curly braces in the output.
Hard to tell what's going on exactly; seems like it could be
corrupt catalog data or faulty code modifications. Or maybe
there's something wrong with whatever the viewing tool is?
regards, tom lane