Understand the importance of Database data normalization
Normalization of data can be defined as a process during which the existing tables of a database are tested to find certain data dependency between the column and the rows or normalizing of data can be referred to a formal technique of making preliminary data structures into an easy to maintain and make efficient data structure
With data normalization any table dependency detected, the table is restructured into multiple tables (two tables) which eliminate any column dependency. Incase data dependency is still exhibited the process is repeated till such dependency are eliminated. The process of eliminating data redundancy is based upon a theory called functional dependency
Importance of normalization
- It highlights constraints and dependency in the data and hence aid the understanding the nature of the data
- Normalization controls data redundancy to reduce storage requirement and standard maintenance
- Normalization provide unique identification for records in a database
- Each stage of normalization process eliminate a particular type of undesirable dependency
- Normalization permits simple data retrieval in response to reports and queries
- The third normalization form produces well designed database which provides a higher degree of independency
- Normalization helps define efficient data structures
- Normalized data structures are used for file and database design
- Normalization eliminate unnecessary dependency relationship within a database file
Below are forms of normalization
First normal form (1NF)
Refers to the first step where preliminary data structures are transforming into the first normal form by eliminating any repeating sets of data elements. A relation table is said to be on the first normal form, if and only if it contains no repeating groups that is it has no repeated value for a particular attribute with a single record. Any repeated group of attribute is isolated to form a new relation. In other words first normal form (1nf) means that a table has no multiple value attribute or composite attribute, In the 1nf, each column holds one attribute and each row holds a single occurrence of the entity
Second normal form (2NF)
2nf concentrated on records with concatenated keys, they check the non key attribute for dependency on the entire key, and any data element that dependent only on part of the key is moved to a new entity
Third normal form (3NF)
All data element in the third normal form must be a function of the key. To reach the 3nf, you need to review the structure’s non-key data elements and identify any data element dependent on an attribute other than the key, if there is all these data elements should be moved to a new entity
Fourth normal form (4NF)
In data normalization, the fourth normal form deals with data element with issues of multi-value dependency (when one attributes determine another attribute sets). A relation is said to be in the 4nf formal form if and if only all existing multi-value dependency is converted into functional dependency
Fifth normal form (5NF)
Here is where the join dependency is removed, the 5nf is also known as the projection join normal form(PJNF), and refers to the separation of one relation into any sub-relations or having sub-relations into one relation and can produce join dependencies
Other Related Articles
- Software Quality Assurance and Management
Software quality may be defined as conformance to explicitly functional and performance requirement explicitly documented developed standard and implicit characteristic that are expected of all professionally...
- Software Quality Assurance Standard
This describes quality assurance elements in geometric terms that can be applied to any business regardless of product or services offered, they have been adopted by many countries which intern permits ISO...
- System testing and implementation
Testing is done all the way in system development. It is meant to turn up any unkown problem. Not to demonstrate the perfection of a program's manual or equipment. Though it is tediou, its help to assure the...
- What is Feasibility Study
The contents of feasibility study should include 1. Project Name - Should be relevant to what you are going to achieve 2.Description of of the problem to be solved 3. It should have a statement of critical...
- Do you know the kind of system Level that exist in your organization
There are system types that exist in an organization and wiil discuss the following four kind. Operational level system This refers to information system that monitors the element ary activities and...
- Types of Organizational System
There are so many types of organizational systems available in an organization. The systems depends with the activities and the number of staff it support. Below are the existing system found in an...
- Understanding Quantitative Methods
Quantitative Techniques refers to the mathematical or statistical techniques use by the business organization to make business decision or formulation of a business plan. However some other terms are also...
- What is a data flow diagram?
Data flow diagram is a geographical tool that shows, process, flows, stores and external entities in a system. Dataflow diagram shows the transformation of data into a system. Dfd has got the following...
More by this Author
Writing minutes these days is not left to the secretary alone. With the availability of portable computers you may attend a meeting without your secretary and you are required to produce minutes. Many people do not know...
Topology is a characteristic of a Local Area Network. It is both the physical configuration of the cabling used to connect computers in the network, and the logical way in which the system views the structure of the...
A repeater is the simplest facility used for network interconnection, whose major function is to receive a network signal from one LAN terminal cable segment and to regenerate and retransmit the signal as it is in its...