Discipline is instruction and teaching, ideally BEFORE a transgression. They have to be taught right behavior, reproved when they violate those standards, and corrected to bring them back to right behavior, always in a teaching mode. Discipline is part of being a disciple. Children should be disciples of their parents.
IMO, corporal punishment, spanking should only be used in matters of defiance, not for simple disobedience.
Personally, I've not met many parents with multiple children who don't or haven't spanked. I've met many parents of spoiled children who didn't spank or didn't spank properly.
Spanking is an effective technique when used properly, but is ineffective, even destructive, when improperly used.