using deferred on PK/FK relationships

Can deferrable etc be used when deleting primary key records (master
table), then reinserting them without losing foreign key records
(slave table)? I ask because in our testing we can't; we lose the
foreign key records in the slave table. I'm guessing we are trying to
abuse the feature.

here's a test script we tried:

drop table master;
CREATE TABLE master (
id integer NOT NULL,
Primary Key (id)
);
insert into master values (1);
insert into master values (2);

drop table slave;
create table slave (
id int,
foreign key (id)references master (id) on update restrict on
delete cascade INITIALLY DEFERRED)
;

insert into slave values (1);
insert into slave values (1);

Then:

test=# BEGIN;
BEGIN
test=# SET CONSTRAINTS ALL DEFERRED;
SET CONSTRAINTS
test=# delete from master;
DELETE 2
test=# insert into master values (1);
INSERT 20959595 1
test=# insert into master values (2);
INSERT 20959596 1
test=# select * from slave;
id
----
1
1
(2 rows)

test=# commit;
COMMIT
test=# select * from slave;
id
----
(0 rows)

test=#

Our hope was that after the commit, slave would retain the original
rows.

cheers
--
Dan Langille