Why is redundant data problematic in databases?

Redundant data in databases is problematic because it wastes storage space and can lead to inconsistencies and errors.

In more detail, redundant data refers to the unnecessary duplication of data within a database. This can occur when the same piece of information is stored in more than one place. While it might seem harmless, redundancy can cause several issues. Firstly, it can lead to a waste of storage space. As databases grow and become more complex, the amount of redundant data can increase significantly, taking up valuable storage resources. This is particularly problematic in large-scale databases where storage space is at a premium.

Secondly, redundant data can lead to inconsistencies. If the same piece of data is stored in multiple places, there is a risk that it might be updated in one place but not in others. This can result in different parts of the database having conflicting information, leading to confusion and errors. For example, if a customer's address is stored in two different tables and it is updated in one but not the other, the database will contain inconsistent information about the customer's location.

Thirdly, managing redundant data can be time-consuming and costly. It requires additional effort to ensure that all instances of a piece of data are updated consistently. This can increase the complexity of database management tasks and lead to higher costs in terms of time and resources.

Lastly, redundant data can also impact the performance of the database. When data is duplicated, it can slow down the process of querying and retrieving information from the database. This can lead to slower response times and a less efficient system overall.

In order to avoid these issues, it's important to design databases in a way that minimises redundancy. This often involves using techniques such as normalisation, which is a process of organising data in a database to reduce redundancy and improve data integrity. By carefully planning and managing the structure of a database, it's possible to minimise the problems associated with redundant data.