Database Normalization Srikanth Karra Instructor: Dr. Steven Case Southern New Hampshire University When we design a database for a relational system, the main objective in the development of a logical data model is to create an accurate representation of the data its relationship and constraints. The data should be split in different tables, which can then be joined together based on their relations with each other and the data found in each one of them. These tables should therefore be designed well to save on space and ensure that cases on data inconsistency are eliminated. Another aspect, which will be saved on, is space that is occupied by repetitive data. Normalization is the process that is used to remove redundancy …show more content…
It is highly recommended by practitioners that all databases be designed to at most the third normal form as there’s little or no benefit designing to the higher normal forms. The type of activity or transactions to be performed against the database should determine how normalized this database will be to achieve the performance benefits. Importance of having a normalized database There are many advantages to normalizing databases. The first being the ability to minimize modification anomalies by reducing redundancy, maintain data consistency and protect data integrity. Data consistency is the act on ensuring that similar data does not appear in different tables or entries in the database. This is highly discouraged because inconsistency can result into a lot of losses in terms of space and time. It can be confusing and especially when updating the data which has multiple entries. A database should therefore be well designed to ensure that all the data is well documented and all inconsistency has been eliminated in the tables. Normalization is a process for evaluating and correcting tables to minimize the likelihood of data anomalies. Basically, normalization can help ensure the proper data is entered into any particular field by restricting what can be entered or stored in that particular field (Kroenke, 2006). The essence of data normalization is to split your data into several tables that will be connected to each other based on the data within them
There are three stages to normalization, 1st NF, 2nd NF, and 3rd NF. In the 1st NF stage must ensure that the table has no multivalued attributes. If there are the table should be broken down into separate tables so that there are no multivalued attributes. The 2nd NF stage requires that we break the tables down even more to ensure that all attributes and functional dependency entirely to the primary key and has met all requirements of the 1st NF. Then, and only then will it be considered to have met 2nd NF requirements. To transform the database to 3rd NF you must identify the primary key in the 2nd NF table. Then we must identify functional dependencies in the relationship to ensure there are no transitive dependencies. These types of dependencies can cause insertion, deletion, and update
Hence, this session has enhanced my understanding about normalization and how essential to create a data that is well organized with the relationships clearly defined and established between the tables (based on the business rules) in order to eliminate data redundancy and inconsistency.
Normalization for entity-relationship modelling works as it does for other modelling systems, with some alterations. [13] The difference when using the entity-relationship data model is [14]:
It is a design method that used to avoid data redundancy and eliminate uncoordinated relationship. Normalisation has six stages to help with separate data which are UNF, 1NF, 2NF, 3NF, BCNF, 4NF and 5NF.
First our team will talk about how Microsoft Access was used to create these tables by Huffman Trucking Database. Then how we used the tables with made up information to be tested on. Then on how we used forms in the maintenance database system. While the creation of relationships and normalization is explained in the process of using queries to search the database (University of Phoenix, 2007).
Campbell, R. J. (2015). Database Design: What HIM Professionals Need to Know. AHIMA. Retrieved from http://library.ahima.org/xpedio/groups/public/documents/ahima/bok1_024637.hcsp?dDocName=bok1_024637
Data normalization is a process by which large tables are divided into smaller tables, and then relationships are defined between them. These relationships could be one-to-one, one-to-many, or many-to-many. The idea behind normalization is to eliminate redundant information and avoid data anomalies that could compromise the integrity of your data. Additionally, you can reduce the amount of space your database consumes and cut the need for
It is used to lower the database redundancy to keep database consistency for long term. Normalization is the set of rules and protocol that defines how the information should be stored into database entities. This process increases the number of database objects (entities) by dividing one database table in to multiple smaller table with proper link (Relationship) in between them. There are myriads of advantages for normalizing database, few are as follows:
Normalization is a process in the database design process which is done to ensure that the right data is in the right table. It helps to overcome the update problems. There are various forms of normalization namely 1NF, 2NF, 3NF, 4NF and 5NF. Another type of normalization is BCNF.
As a commonly exercised technique for the analysis of relational databases, normalization creates set of relational tables and minimize data redundancy that preserve consistency (Bahmani et al, 2010). The output design then facilitates correct insertion, deletion, and modification to the data.
This document is set up to give a planned view of an initial study of a new database design to be incorporated by a client’s day-to-day operations. The study done also will shed some light on the company’s operations, structure, database constraints and objectives.
At first any database should be designed with the end user in mind. Logical database design, also referred to as the logical model, is the process of arranging data into logical, organized groups of objects that can easily be maintained. The logical design of a database should reduce data repetition or go so far as to completely eliminate it. The needs of the end user should be one of the top considerations when designing a database.
· Structuring the data in the warehouse as either third normal form tables or in a star/snowflake schema that is not normalized
With the completion of the logical model, a physical model is outlined to portray the actual design of a database. Physical modeling illustrates the integration of the data requirements that were recognized during logical modeling into a system structure that will be implemented. A physical model creates objects using symbols such as tables and columns based on entities and attributes that were defined during logical modeling. Constraints, such as primary keys, foreign keys and other unique keys, are defined in this modeling phase. It is crucial to have a well-informed, knowledgeable design team in the development of the physical model. “To ensure that all information system needs are met, physical models are often developed jointly by a team representing the data administration, database administration, and application development areas” (CA ERwin Data Modeler Methods Guide – CA, n.d.). Physical modeling is database specific, which means the objects defined during physical modeling can vary depending on the database software being used. The hardware of a company
The main components of a relational database are rows, columns, and tables. The tables are known as relations, or files. The rows are called tuples, or records. The columns are called attributes, or fields. In order for a table to be a relation, rows must contain data about an entity, or something. Columns must contain data about attributes of the entity (quantity, tax, etc.), and cells must contain a single value only. All entries in a column are of the same type. Each column has a unique name, and no two rows can be identical. The order of both the rows and columns is not important. The other components of a relational database are forms, queries, reports, and also macro and module. A macro is a sequence of instructions that we give a single name to- it can provide extra features and functionality, and the module is written in a programming language and then run when need be. It also lends extra functionality to the database. The forms are used to enter one record at a time, the queries are used to search through the data for the answer to our question, and the report