Under oath will begin with a deposition. A wide range of questions will be allowed.
Leaks of information happen often in depositions, and one could safely assume it might happen with one on Hillary. Still, depositions are subject to objection by council and I'd bet the farm Hillary's attorney will object to anything they don't want testified to and the objection sustained if the judge is politically left. Having said that, I'd love to be the fly on the wall during it. More, I hope she actually has to tell the truth about something. It would be a first. "I don't remember" should only work so many times before someone is called down on it.