Japin Li <japinli(at)hotmail(dot)com> writes:
> Yeah, the single-user mode works. Thank you very much!
> However, if the database is in production, we cannot go into single-user mode,
> should we provide an option to change this behavior on the fly?
There is not, and never will be, a version of Postgres in which
it's impossible for a superuser to shoot himself in the foot.
Test your settings more carefully before applying them to a
production database that you can't afford to mess up.
regards, tom lane