Simple steps to Normalize

Posted Date: 11 Mar 2008 Resource Type: Articles/Knowledge Sharing Category: Placement Papers

Posted By: ramya Member Level: Gold
Rating:

Points: 3

First normal form (1NF) sets the very basic rules for an organized database:
Eliminate duplicative columns from the same table.
Create separate tables for each group of related data and identify each row with a unique column or set of columns (the primary key).

Second normal form (2NF) further addresses the concept of removing duplicative data:
Meet all the requirements of the first normal form.
Remove subsets of data that apply to multiple rows of a table and place them in separate tables.
Create relationships between these new tables and their predecessors through the use of foreign keys.

Third normal form (3NF) goes one large step further:
Meet all the requirements of the second normal form.
Remove columns that are not dependent upon the primary key.

Finally, fourth normal form (4NF) has one additional requirement:
Meet all the requirements of the third normal form.
A relation is in 4NF if it has no multi-valued dependencies.

Remember, these normalization guidelines are cumulative. For a database to be in 2NF, it must first fulfill all the criteria of a 1NF database.

Responses

No responses found. Be the first to respond and make money from revenue sharing program.

Feedbacks

Popular Tags

What are tags ?

Search Tags

(No tags found.)

Post Feedback

This is a strictly moderated forum. Only approved messages will appear in the site. Please use 'Spell Check' in Google toolbar before you submit.
You must Sign In to post a response.

	Next Resource: SQL interview Q&A - 6
	Previous Resource: ACID properties
	Return to Discussion Resource Index
	Post New Resource
	Category: Placement Papers

Post resources and earn money!

Related Resources

Fresher Jobs

Resources

Colleges

Simple steps to Normalize

Responses

Post Feedback