What is a situation called where unnecessary duplication of data occurs in a database, causing issues?

The situation where unnecessary duplication of data occurs in a database is known as data redundancy. This concept refers to the presence of the same piece of data in multiple places within the database, which can lead to various problems such as increased storage costs and data inconsistencies.

When data is redundant, if one instance of the data is updated, it may not be reflected in other locations where the same data is duplicated. This can create confusion and potentially lead to erroneous conclusions drawn from the data. Proper database design aims to minimize redundancy through techniques like normalization, which organizes the data structure efficiently to eliminate unnecessary duplication. Thus, recognizing data redundancy is crucial for maintaining the integrity and efficiency of a database system.