Gurjeet Singh <singh(dot)gurjeet(at)gmail(dot)com> writes:
> On PG 8.4.4 I am unable to set per-table autovacuum setting for the
> pg_listener table. Being a superuser, I'd expect Postgres to allow me to do
> that.
See allow_system_table_mods. Even superusers should think twice before
fooling with system catalogs...
regards, tom lane