DROP TABLE NODE_1

CREATE TABLE NODE_1 (
DOC_ID INTEGER NOT NULL,
NODE_ID INTEGER NOT NULL,
CONSTRAINT NODE1_CHK 
CHECK (NODE_ID = 1)
ENFORCED 
ENABLE QUERY OPTIMIZATION
)

DROP TABLE NODE_2

CREATE TABLE NODE_2 (
DOC_ID INTEGER NOT NULL,
NODE_ID INTEGER NOT NULL,
CONSTRAINT NODE2_CHK 
CHECK (NODE_ID = 2)
ENFORCED 
ENABLE QUERY OPTIMIZATION
)

DROP VIEW ALL_NODES_V

CREATE VIEW ALL_NODES_V AS
SELECT * FROM NODE_1
UNION ALL
SELECT * FROM NODE_2
WITH ROW MOVEMENT

INSERT INTO ALL_NODES_V VALUES (1,1)

COMMIT

SELECT * FROM ALL_NODES_V

DOC_ID      NODE_ID
----------- -----------
          1           1
  1 records are selected.

UPDATE ALL_NODES_V SET NODE_ID = 1

COMMIT

SELECT * FROM ALL_NODES_V

DOC_ID      NODE_ID
----------- -----------
          1           1
          1           1

  2 records are selected.

CREATE TRIGGER NODE_1_B_UR 
NO CASCADE BEFORE UPDATE OF NODE_ID ON NODE_1 
REFERENCING  OLD AS old  NEW AS new  
FOR EACH ROW MODE DB2SQL 
BEGIN ATOMIC
 if old.node_id = new.node_id then
  set new.node_id = old.node_id;
end if;
END@