Nonrepeatable read

A nonrepeatable read occurs when one user is repeating a read operation on the same records but has updated values, as shown in the following example.

                User A executes: SELECT * FROM State; 
User B executes: 
UPDATE State 
SET state_name = 'Arkansas' 
WHERE state = ‘AK'; 
COMMIT WORK; 
SELECT * FROM pub.State 
User A re-executes: 
SELECT * FROM State;
User A has now updated records in the result set.