/*
 * Here is a more concise example of the problem
 */

CREATE TABLE linkedTable (
        testTableId INT
    ) ENGINE = INNODB;
CREATE TABLE testTable (
        id INT, 
        data CHAR(50), 
        timestamp TIMESTAMP(14)
    ) ENGINE = INNODB;

INSERT INTO linkedTable (testTableId)   VALUES (1);
INSERT INTO testTable   (id,data)       VALUES (1,'original data');
SELECT * FROM linkedTable LEFT JOIN testTable ON testTableId=id;

# Do an update to testTable directly which does not change anything
UPDATE testTable SET data='original data' WHERE id=1;
SELECT * FROM linkedTable LEFT JOIN testTable ON testTableId=id;

# Protect the update with an additional condition in the WHERE clause
UPDATE linkedTable LEFT JOIN testTable ON testTableId=id SET data='original data' WHERE id=1 AND data<>'original data';
SELECT * FROM linkedTable LEFT JOIN testTable ON testTableId=id;

# Do an update to testTable linked to linkedTable which should not change anything
UPDATE linkedTable LEFT JOIN testTable ON testTableId=id SET data='original data' WHERE id=1;
SELECT * FROM linkedTable LEFT JOIN testTable ON testTableId=id;

/**********************************************************************
 * Wait at least one second before doing the following statements
 **********************************************************************/

# Do an update to testTable directly which does not change anything
UPDATE testTable SET data='original data' WHERE id=1;
SELECT * FROM linkedTable LEFT JOIN testTable ON testTableId=id;

# Protect the update with an additional condition in the WHERE clause
UPDATE linkedTable LEFT JOIN testTable ON testTableId=id SET data='original data' WHERE id=1 AND data<>'original data';
SELECT * FROM linkedTable LEFT JOIN testTable ON testTableId=id;

# Do an update to testTable linked to linkedTable which should not change anything
UPDATE linkedTable LEFT JOIN testTable ON testTableId=id SET data='original data' WHERE id=1;
SELECT * FROM linkedTable LEFT JOIN testTable ON testTableId=id;