UPDATE sql statement

[zwxx960]

Hi,
Having trouble executing "UPDATE" sql statement in cluster:

Whenever try to use "UPDATE" sql statement combined with "EXISTS" condition like:

UPDATE table_A T1
SET name="A"
WHERE EXISTS (SELECT 1 
                             FROM table_B T2
                            WHERE T1.id=T2.parent_id)

will get exception like:

There are not enough rules to produce a node with desired properties: convention=LOGICAL, sort=(],
DistributionTraitDef=ANY. All the inputs have relevant nodes, however the cost is still infinite.

Could anyone maybe give a hint about what's going wrong?