unique heritage

Hi everyone,

I'm trying to understand the heritage with postgres....

I have a table called iface with (Physik macaddr UNIQUE, logik cidr)
and another table called komputer with (OS varchar(50)) inherits (iface)

I logically have komputer with OS, physik and logik)... But what i don't
get is why physik in komputer is no more unique, while it's still is in
iface.... All attributes aren't inherited then ?... i thought i saw the
same thing about IDs (and serial), but as ID are not necessary
everywhere, i did not bother)... but here, in this example (and in my
real DB) there is a problem because i can enter serveral time the same
mac adress... and i shouldn't !

Thanks for any tips....

Stephane