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What is Normalization in DBMS?

Normalization is the process of removing or getting rid anomalies or errors, then making the database to be in steady status. If a database design is not good, it may have irregularities, which are very bad for every database administrator. It is impossible to manage a database effectively the database contains anomalies.

1. Update anomalies: If data items were dispersed and are not connected to each other accurately, then it could lead to odd conditions. For instance, when we try to update one data item having its duplicates dispersed over several places, a few items get updated correctly while a few others are left with old values. Such items leave the database in an incompatible status.

2. Deletion anomalies: We tried to delete a record, but parts of it were left undeleted because of lack of attention or ignorance, the data is also saved somewhere else in the database.

3. Insert anomalies: We tried to insert data in a record that does not exist at all.

What is First Normal Form in DBMS?
First Normal Form rule states that all the attributes in a relation must have atomic domains. It is described in the definition of relations (tables) itself. The values in an atomic domain are undividable units.

What is Second Normal Form in DBMS?

Second normal form rule states that non-key attributes for instance Stu_Name and Sub_Name must be dependent upon both and not on any of the prime key attribute independently.

1. Prime attribute: It is an attribute which is a part of the prime-key.

2. Non-prime attribute: It is an attribute, which is not a part of the prime-key.

If second normal form rule is being followed, then every non-prime attribute should be fully functionally dependent on prime key attribute. That is, if X → A holds, then there should not be any appropriate subset Y of X for which Y → A also holds true.

What is Third Normal Form Rule?
For a relation to be in Third Normal Form rule it must be in Second Normal form rule and the following must satisfy:
1. No non-prime attribute is transitively dependent on prime key attribute.
2. For any non-trivial functional dependency, X → A, then either:
o X is a super key or,
o A is prime attribute.

What is Boyce-Codd Normal Form?
Boyce-Codd Normal Form (BCNF) is an extension of Third Normal Form on firm terms. BCNF states that for any non-trivial functional dependency, X → A, X must be a super-key.

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