No; not literal ovens. However, as you said, they did put Jew's, Gypsies and homosexuals in gas chambers. I guess it must have felt like an oven, due to the deterioration of the skin caused by the chemicals used to kill them...?
Oh, yeah. There are so many horrible, disgusting "jokes" about this kind of thing. I'm not even Jewish and I find it offensive. It was truly sick and horrible.
Anyway... Hope I helped?'
EDIT: Okay, then. I guess they really did burn them alive. I didn't know that! That's just as bad... Horrible, horrible, HORRIBLE!