Constructors in clases

is the following possible in postgresql 7.4?

create table t1 (name varchar(10), age int2);

create table t2 (position varchar(20), worker t1);

if it is then how do i insert a record in t2? in the documentation i´ve read about object relational dbs there is some constructor involved but i´m not sure how to work with it.

any help with this will be highly apreciated!