What is the update anomaly?

The update anomaly occurs in a database when changes to data are not consistently applied across all instances, leading to data integrity issues. For example, if a customer's address is updated in one record but not in others, it results in discrepancies. This problem often arises in poorly designed database schemas, particularly those that are not normalized, where the same piece of information is stored in multiple places. To mitigate update anomalies, databases should be normalized to reduce redundancy and ensure that updates propagate correctly.