Database Normalization – Why It Is Important

Database normalization can be defined as the process through which data is efficiently organized within a database and involves the management of attributes (columns) and relations (tables) of a relational database in an effort to lower the chances of data redundancy ever occuring. This form of normalization generally encompasses the decomposition of a table into smaller and less redundant tables without them losing information; allowing for all foreign keys to be defined in the older table while referencing the main keys of the newer ones.

The main objective of database normalization is to isolate data in a way that any additions, modifications, and deletions of an attribute can be done in just a single table before been propagated through the entire database using the newly defined foreign keys. One of the most common examples of normalization can be seen where in the instance where an entity’s unique ID is stored all over a system but its title name is held within a single table. Its name can easily be updated in a single row of one table.

Database Normalization Objectives

This form of normalization is generally handled for a couple of reasons. This article will be discussing the objectives of database normalization to help you better understand them and why they are important.

Objective #1: To Free The Database Of Any Modification Anomalies

When any attempts to modify – insert into, delete from, or update – a table, unwanted side-effects could arise within the tables that haven’t been sufficiently normalized. Such tables are generally characterized with anomalies such as these:

•           The same information being expressed on different rows. As such any updates made to the table could lead to logical inconsistencies generally known as update anomalies.

•           Instances when facts or data cannot be recorded. This is where details entered are not recorded; an inconsistency commonly called insertion anomaly.

•           Deletion of data that represents certain facts necessitating the deletion of totally unrelated data. This irregularity is denoted as a deletion anomaly.

When normalized, such instances are eliminated and all modifications made are reflected as they should be and where they should be without affecting the sanctity of the entire table.

Objective #2: Minimizing Redesign When Extending The Structure Of A Database

When the structure of an already normalized database is extended to allow it to accommodate new data types, the already existing aspects of the structure might remain entirely or largely unchanged. When this happens, applications that interact with the database are slightly affected. A normalized table, and the relation between one table (normalized) and another, reflect real world ideas and their interrelation.

Objective #3: To Avoid Partiality Towards Any Particular Querying Pattern

Normalized database tables are generally appropriate for general purpose querying. As such, any queries against such tables, including all future queries whose specifics cannot be easily predicted, are supported. This is in contrast with tables that aren’t normalized as they tend to selectively lend themselves to some kinds of queries and not to others.

As you can see, normalizing your database will make things easier for you as it streamlines how data is entered, managed and stored within the entire database. As such, this is something that you need to consider doing. However, it is important to note that it is not an absolute requirement. Nonetheless, it is something that should not be overlooked if you want to enjoy streamlined data management within a database.