Rules of data normalisation, Database Management System

Rules Of Data Normalisation

 Let us now summarise Normalisation with the help of various clean rules. The following are the necessary rules for the Normalisation process:

1.   Eliminate Repeating Groups: Make an individual relation for each set of related attributes, and give every relation a primary key.

2.   Eliminate Redundant Data: If an attribute relies on only part of a multi- attribute key, remove it to an individual relation.

3.   Eliminate Columns Not Dependent On Key: If attributes do not give to a description of the key, remove them to a individual relation.

4.   Isolate Independent Multiple Relationships: No relation may have two or more 1:n or n:m relationships that are not directly linked.

5.   Isolate Semantically Related Multiple Relationships: There may be practical constrains on information that give explanation for separating logically related many-to-many relationships.

Let's define these steps of Normalisation through an instance:

 Let us make a file of all the employees in the company. In the original employee file, every employee name is pursued by any databases that the member has experience with. Some may know many, and others may not know any.

Emp-ID

Emp-Name

Database-Known

Department

Department- Loc

1

Gurpreet

Malhotra

Oracle,

A

N-Delhi

2

Faisal Khan

Access

A

N-Delhi

3

Manisha Kukreja

FoxPro

B

Agra

4

Sameer Singh

DB2, Oracle

C

Mumbai

Posted Date: 3/7/2013 2:25:30 AM | Location : United States







Related Discussions:- Rules of data normalisation, Assignment Help, Ask Question on Rules of data normalisation, Get Answer, Expert's Help, Rules of data normalisation Discussions

Write discussion on Rules of data normalisation
Your posts are moderated
Related Questions
Code an Oracle Database trigger to enforce the constraint that an employee can never change his or her department.

he SQL query that will return the order number, quantity ordered, price each and total cost of an order (quantity * price each) from the order details table. Label the calculated c

This project requires you to create a database design.  Your design will be documented in a set of Entity-Relationship diagrams.  Draw a set of Entity-Relationship diagrams to mode

Package classes and associations into models  Programs are made of separate physical units which could be edited, imported, complied or otherwise manipulated. The careful part

Define a job scheduling strategy that will meet business requirement of reporting availability by 6am CST for the following cubes? Show the job scheduling dependencies in a pictori

What are the several forms of identity? a) Value b) Name c) Built-in

Define tuple variable Tuple variable is a type of variable whose domain is the set of all tuples.

I want a script that will run, and update my virtual machine's LAN settings (proxy server and port), and also re-configure the Firefox User Agent. I want a script that will run,

Question: (a) What are the challenges in the development of Large Scale Distributed Real Systems? (b) What is backward engineering and forward engineering in a design packa

What is a hash index? A hash index organizes the search keys, with their associated pointers, into a hash file structure.