What are the three data anomalies that are similarly to take place as a result of data redundancy? Can data redundancy be completely eliminated in database approach? Why or why not?
Ans: The most common anomalies considered when data redundancy exists are:
Update anomalies, addition anomalies, and deletion anomalies. All these can simply be avoided through data normalization. Data redundancy generates data integrity problems, caused by the fact that data entry failed to conform to the rule that all copies of redundant data should be similar. The data redundancy cannot be completely removed from the database, but there should be controlled redundancy. Occasionally redundancy is allowed to overcome the problem of excessive join operations for computing queries.