Unique constraint for inherited tables

I am defining a table t1 with a NOT NULL field f1 and UNIQUE field f2.
(it automatically defines t1_f2_key unique index)

I am defining now a new table t2 that inherits t1 table and add some
columns.

The NOT NULL constraint is preserved for f1 field, the UNIQUE for f2 not
(the index t2_f2_key) is not defined.

Wouldn't be normal that the unique constraint to be inherited also in
t2?

Constantin Teodorescu
FLEX Consulting Braila, ROMANIA