faster or ..... ????

Hii all,
I eould like to asking about creating table in postgres
here is the
1> can postgres do such things like this one?
# create table address as object(address varchar(100), post(6));
# create table id (id integer not null primary key,
name char(100),address);

now i will
compare with this one >>
# create table id (id integer not null primary key, name char(100));
# create table address (id integer not null references id,
address varchar(100), post(6));

which is most faster???

Thank you very much for all your kind to answer my question
and my english is so bad isn't?

Dedy Styawan
Semarang