We’ve covered most of the basic concepts for designing a logical model, including those that help hold data together and keep it accurate. We’re now moving into some final but critical concepts to ensure your data is atomic and stays intact.
Discover Normalization and its Importance
Normalization is another step in the design process to ensure your data is easily maintainable and updated without much worry of it being stored in multiple places or updated everywhere. One of the primary concepts of a relational database is the ability to store, update, and manipulate data in one place, which virtually eliminates the potential for duplicate or out-of-date data.
You normalize your database tables for two key reasons:
To eliminate data redundancy.
To ensure that you have logical entities, i.e., that all related data is stored logically and together.
If we already have our entities defined, isn’t that good enough to build a database?
No, since there is no guarantee that you eliminated all of the anomalies. With the process of normalization, you determine where attributes are grouped together to form entities that have the least likelihood of producing any data anomalies and the best chance for a cohesive database that functions as designed.
Examine the Headache of Non-Normalized Database Tables
As you can imagine, a non-normalized database would have tables that may contain duplicate data in multiple locations and would end up being a headache to maintain. In some instances, it may be impossible to update all duplicate data. As you can guess, this would result in records with very poor reliability and accuracy, resulting in a system that few would want to use due to its inconsistency.
Non-normalized tables take up more storage space and clutter existing tables with unnecessary table entries. Other issues may include slow response times to queries or other transactions, inaccurate data retrieved, or unexpected results.
Overall, the database would become inefficient to maintain and use. The issues would continue to grow over time as more data is added.
Normalization helps ensure duplicate data is not saved anywhere within the database.
The process of normalization often leads to the creation of additional tables to prevent duplicate data.
We've got the basics of normalization down. Let's go step by step through achieving first, second, and third normal forms.