BUG #5606: DEFERRABLE and DEFERRABLE INITIALLY DEFERRED are the same

The following bug has been logged online:

Bug reference: 5606
Logged by: Frank Heikens
Email address: f(dot)heikens(at)anva(dot)nl
PostgreSQL version: PostgreSQL9.0b4
Operating system: WinXP
Description: DEFERRABLE and DEFERRABLE INITIALLY DEFERRED are the
same
Details:

Today I checked out the wiki and did some tests using the deferrable unique
constraints described at:
http://wiki.postgresql.org/wiki/What%27s_new_in_PostgreSQL_9.0#DEFERRABLE_UN
IQUE_CONSTRAINTS

I copied/pasted the examples and to my surprise, DEFERRABLE and DEFERRABLE
INITIALLY DEFERRED work exactly the same, there is no need to use
CONSTRAINTS ALL DEFERRED; at all. The wiki and manual describe the need for
this, but no matter what, it always works the same. (see tests and results
below)

It's tested on a local machine, Windows XP, 32bit, using the
EnterpriseDB-installer:
PostgreSQL 9.0beta4, compiled by Visual C++ build 1500, 32-bit

-- Test 1
CREATE TABLE test (a int primary key);
INSERT INTO test values (1), (2);
UPDATE test set a = a+1;
-- Result: Error: duplicate key value violates unique constraint
"test_pkey"
-- This is Ok.

-- Test 2
CREATE TABLE test (a int primary key deferrable);
INSERT INTO test values (1),(2);
UPDATE test set a = a+1;
-- Result: Query returned successfully: 2 rows affected, 15 ms execution
time.
-- Not Ok, see the manual and wiki, should result in the same error as test
1.

-- Test 3
CREATE TABLE test (a int PRIMARY KEY DEFERRABLE INITIALLY DEFERRED);
INSERT INTO test values (1),(2);
UPDATE test set a = a+1;
-- Result: Query returned successfully: 2 rows affected, 31 ms execution
time.
-- This is Ok.

Each test was executed using it's own connection.

If you need more information, just let me know.

Kind regards,

Frank Heikens
PostgreSQL DBA

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