Decision boundaries

[gthampi]

I have been working with some basic classifiers and looking at the decision boundaries they create.
My question is how do decision boundaries look if some of the independent variables (the features) are categorical rather than numeric.
Would they still look like hyperplanes (assuming data is linearly separable)
If so how would these hyperplanes look ?

[editor]

For categorical variables, decision boundaries will be axis-parallel straight lines.
A categorical variable is like a numerical variable which only takes 0 and 1 values