Inserting into a table backed by pre-join projection HASH JOIN problem

gistfile1.sql

drop table test_1 cascade;
drop table test_2 cascade;

CREATE TABLE test_1 
( 
a date NOT NULL, 
b char(8) NOT NULL, 

PRIMARY KEY (a), 
UNIQUE (b) 
); 

CREATE PROJECTION test_1_super_by_a 
( 
a ENCODING RLE, 
b ENCODING RLE
) 
AS 
SELECT * FROM test_1 
ORDER BY a, b
SEGMENTED BY MODULARHASH(b) ALL NODES; 


CREATE TABLE test_2 
( 
a date NOT NULL, 
c char(8) NOT NULL, 
d char(8) NOT NULL, 

PRIMARY KEY (a, c, d), 
FOREIGN KEY (a) REFERENCES test_1 (a)
); 

CREATE PROJECTION test_2_super_by_a 
( 
a ENCODING RLE, 
c ENCODING RLE, 
d ENCODING RLE,

a_duplicated,
b
) 
AS 
SELECT *
FROM test_2 
JOIN test_1 ON (test_2.a) = (test_1.a)
ORDER BY test_2.a, test_2.c, test_2.d
SEGMENTED BY MODULARHASH(d) ALL NODES;

INSERT INTO test_1 VALUES('2013-01-01', 'foobar');
SELECT ANALYZE_STATISTICS('');

-- HASH JOIN
EXPLAIN INSERT INTO test_2 VALUES ('2013-01-01', 'TEST0000', 'TEMP0000');

-- Access Path:
-- +-DML INSERT [Cost: 0, Rows: 0]
-- |  Target Projection: mab_test.test_2_super_by_a (RESEGMENT)
-- |  Target Prep:
-- | +---> JOIN HASH [Cost: 35, Rows: 0] (PATH ID: 1) <-- should be merge join
-- | |      Join Cond: (test_2.a = test_1.a)
-- | | +-- Outer -> SELECT [Cost: 0, Rows: 0] (PATH ID: 2)
-- | | +-- Inner -> STORAGE ACCESS for test_1 [Cost: 34, Rows: 1] (PATH ID: 3)
-- | | |      Projection: mab_test.test_1_super_by_a
-- | | |      Materialize: test_1.a, test_1.b

-- MERGE JOIN
EXPLAIN INSERT INTO test_2 SELECT '2013-01-01', 'TEST0000', 'TEMP0000';

-- Access Path:
-- +-DML INSERT [Cost: 0, Rows: 0]
-- |  Target Projection: mab_test.test_2_super_by_a (RESEGMENT)
-- |  Target Prep:
-- | +---> JOIN MERGEJOIN(inputs presorted) [Cost: 709, Rows: 10K (NO STATISTICS)] (PATH ID: 1)
-- | |      Join Cond: (test_2.a = test_1.a)
-- | | +-- Outer -> SELECT [Cost: 663, Rows: 10K (NO STATISTICS)] (PATH ID: 2)
-- | | | +---> STORAGE ACCESS for dual [Cost: 663, Rows: 10K (NO STATISTICS)] (PATH ID: 4)
-- | | | |      Projection: v_catalog.dual_p
-- | | | |      Materialize: dual.dummy
-- | | +-- Inner -> STORAGE ACCESS for test_1 [Cost: 34, Rows: 1] (PATH ID: 5)
-- | | |      Projection: mab_test.test_1_super_by_a
-- | | |      Materialize: test_1.a, test_1.b