drawing elements: why only one index buffer

I am currently drawing using glDrawArrays. I am looking at using 
DrawElements instead.  But I notice that it would still require my 
normals and vertex coords to have a 1:1 relation****p.  Is there not a 
way to have a index buffer for verts-coords, and normals seperately?

i.e., drawing a triange face:

v[] = { 0,0,0,
         1,1,0,
         0,1,0 }

n[] = { 1,0,0
         1,0,0,
         1,0,0 }

I really only need one normal, but if I must use the same index for all, 
I am forced to use three.

Is there a technical reason? (i.e, h/w limations)

Am I missing something?

Thanks,

~S