 NULL’ing Out 
 
Simply deleting a column of data by replacing it with NULL values is an effective 
way of ensuring that it is not inappropriately visible in test environments. 
Unfortunately it is also one of the least desirable options from a test database 
standpoint. Usually the test teams need to work on the data or at least a realistic 
approximation of it. For example, it is very hard to write and test customer account 
maintenance forms if the customer name, address and contact details are all NULL 