What is normalization and what are the different forms of
normalizations?
Answer Posted / swapna
Normalization is the process of efficiently organizing data
in a database. There are two goals of the normalization
process: eliminate redundant data (for example, storing the
same data in more than one table) and ensure data
dependencies make sense (only storing related data in a
table). Both of these are worthy goals as they reduce the
amount of space a database consumes and ensure that data is
logically stored.
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
Is This Answer Correct ? | 28 Yes | 3 No |
Post New Answer View All Answers
How would you use user_constraints table in DB?
Is a primary key unique?
What guidelines should be followed to help minimize deadlocks?
What is an index. What are the types?
How adventureworkslt tables are related?
Why use “pivot” in sql server?
How to trouble shoot if unable to connect SQL Server
Can you explain different types of joins?
Explain alternate key, candidate key and composite key in sql server?
whats the maximum size of view state??
What do we have to check in database testing?
Explain insert into select statement?
What is an active database?
How to list all schemas in a database?
explain what is a schema in sql server 2005? Explain how to create a new schema in a database? : Sql server database administration