# What is Normalization ?

Answer : Normalization is the process of reorganizing data in a database…
• Normalization is the process of reorganizing data in a database. They have two basic requirements they are:
• No redundancy of data.
• Logical as data dependencies.
• To normalize a database, we divide the database into tables and establish relationships between the tables.
• Database normalization can essentially be defined as the practice of optimizing table structures.
• Optimization is accomplished as a result of a thorough investigation of the various pieces of data that will be stored within the database, in particular concentrating upon how this data is interrelated.

• 1NF
• 2NF
• 3NF
• BCNF
• 4NF
• 5NF

## First Normal Form (1NF)

• The First Normal Form should be following some rules in table,
• It should only have single(atomic) valued attributes/columns.
• Values stored in a column should be of the same domain
• All the columns in a table should have unique names.
• And the order in which data is stored, does not matter.

## Second Normal Form (2NF)

• For a table to be in the Second Normal Form,
• It should be in the First Normal form.
• And, it should not have Partial Dependency.

## Third Normal Form (3NF)

• A table is said to be in the Third Normal Form when,
• It is in the Second Normal form.
• And, it doesn’t have Transitive Dependency.

## Boyce and Codd Normal Form (BCNF)

• Boyce and Codd Normal Form is a higher version of the Third Normal form. This form deals with certain type of anomaly that is not handled by 3NF. A 3NF table which does not have multiple overlapping candidate keys is said to be in BCNF.
• For a table to be in BCNF, following conditions must be satisfied:
• R must be in 3rd Normal Form and, for each functional dependency ( X → Y ), X should be a super Key.

## Fourth Normal Form (4NF)

• A table is said to be in the Fourth Normal Form when,
• It is in the Boyce-Codd Normal Form.
• And, it doesn’t have Multi-Valued Dependency.

## Fifth Normal Form (5NF)

• Fifth Normal Form (5NF), also known as project-join normal form (PJ/NF) is a level of database normalization designed to reduce redundancy in relational databases recording multi-valued facts by isolating semantically related multiple relationships.
• A relation R is in Fifth Normal Form (5NF) and only if the following conditions are satisfied simultaneously,
• R is already in 4NF.
• It cannot be further non-loss decomposed.

## Design a database for a hierarchical data like country, state, zone, street etc., The tags and length of the hierarchy are not specific and they can change anytime ?

Answer : Hierarchical data is a common relational data pattern for representing tree-like data structures…

## What is DBMS ?

Answer : DBMS is represented by the DataBase Management…

## What is indexing in database ?

Answer : Indexing is the One of the ways that will optimize the database searching…

## Characteristics of DBMS ?

Answer : D) all the above…

## What is the concept of ACID properties in DBMS ?

ACID stands for Atomicity, Consisency, Isolation, and Durbility property. Multiple users can share data in a safe and secure way using these properties.  Atomicity: Atomicity is based on the principle…

## What is ER Model in DBMS ?

ER stands for Entity-Relationship model. It is a high level data model. If any data elements or relationship of any specified system can defined using this model. Conceptual design for…