Deferrerable Check constraints

Hi All,

Need a Help. Can a check constraint be deferred until the end of a
transaction  ?
In other words, if i have a constraint like this:

CREATE TABLE test
(
  id serial NOT NULL,
  qt1 integer NOT NULL DEFAULT 0,
  qt2 integer NOT NULL DEFAULT 0,
  CONSTRAINT check_qt CHECK (qt1 <= qt2)
)

There are some manner that allow qt1 to be greater than qt2 on a
intermediate state of the transaction ?

Thanks in Advance

--
Luiz K. Matsumura
Plan IT Tecnologia Informática Ltda.