What consequences can data normalization violations lead to?

Normalization violations can lead to the following problems:

• Insertion Anomaly: It is impossible to add a new record about one object if it depends on information about another object that does not yet exist in the database.
• Deletion Anomaly: When deleting a record about one object, information about another object is automatically deleted, which is not directly related to the first but stored together with it.
• Update Anomaly: To change the same value that is repeated in multiple records, each of these records must be updated. Otherwise, data inconsistency may occur.
• Data Redundancy: The same data is stored in multiple places, leading to increased database size and complicating the maintenance of consistency.
• Data Inconsistency: Different copies of the same data may contain contradictory information.
• Query Errors: Redundancy and inconsistency can lead to incorrect results when executing database queries.
• Maintenance Complexity: Supporting a non-normalized database becomes more labor-intensive and error-prone.

These consequences can significantly reduce the integrity, reliability, and performance of the database.