Had a very good discussion with another member here about the pros and cons of dogs both big and little. Depending on your plan for protecting yourself and your family during a break-in, home invasion, etc,... there is a good chance the dog may also get shot, injured, or stabbed, if the BG(s) have a weapon.
Granted, a 150lb Rottweiler, will scare the crap out of an intruder or two, there is a chance the BG(s), if armed, will just shoot the dog.
Dogs are great for back up "Brinks Security", my little "Toto" aka "rat dog", makes a lot of noise, but he will run away, as he's a big wuss.

But that's OK, he hears better than me, and will provide a precious few seconds to implement my home defense plan. However, I have to prioritize my families well being first, dog second.
Regardless, if your big dog attacks the BG(s), follow your plan to protect yourself and family. As much as I love my damn dog, I love my wife more,..

(Yes the wife is watching me, so to avoid the "ding" to the back of my head, I am going to protect her first).

Welcome to DRTV yuri, post a pic of your schnauzer, dog pics are almost as good as gun pics.
tw