What is Normalization?Normalization is the process of decomposition the table into multiple table to remove the redundancy or to overcome the anomaly problem.
Why Normalization?To remove the Anomaly in table.
What is Anomaly in Table?It is the some redundancy or data lose problem in table.
There are there kind of anomaly problem in table:
1.Insertion anomaly(redundancy problem at insertion time)
2.Deletion anomaly(data lose chance at deletion time)
3.Updation anomaly(redundancy problem at Updation time)
Types of Normalization:(a). 1NF
(b). 2NF
(c). 3NF
(d). BCNF
What is 1NF:For table is in 1NF(first normal form) there are two main condition:
-Each cell of table contain only atomic value.
-Each table of database must have primary key.
What is 2NF:For table is in 2NF(second normal form) there are following condition.
-Table is in 1NF.
-There is no partial dependency in the table.
What is 3NF:For table is in 3NF(Third normal form) there are following condition.
-Table is in 2NF.
-There is no transitive dependency in the table.
What is BCNF:- It stand for Boyce codd Normal form.
- BCNF is a normal form in which for every non-trivial functional dependencies A to B, A must a superkey.
- Also called as 3.5NF.
- In this, there must be chance of data lose in BCNF.
What is partial or transitive dependency:
When any non prime attribute is depending on some prime attribute instead of whole candidate key then this is called as partial dependency.
When any non prime attribute is depending on some other non-prime attribute instead of whole candidate key then this is called as transitive dependency.
What is Prime and non-prime attribute?
Prime attribute is the attribute which is the part of the candidate key.
Non-prime attribute is the attribute which is not the part of the candidate key.