What is need for normalization in dbms?

Answer 1

DBMS stand for data base management system

We normally use dbms systems to improve the management of the data and accesss of the data too.

well if the data is in normal form it is very easy to access it as well as manage it for the system.

In the process of normalization we increase the normality of the data by removing the dependencies redundancy applying the entity integrity and referential integrity.

there are many stages of Normalization process..:

1. 1NF

2. 2NF

3. 3NF

4. BC NF

5. 5NF...etc..

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Addendum:

While the above answer is not incorrect, I don't believe it properly answers the question in a way that anyone who is not already a database expert would understand. The question is this: Why do we need to normalize data in a database. Here is the answer:

First, in order to answer this you have to understand what normalization is. Normalization is the process of removing duplicate information and dependent information from a database.

Lets say for example you have two tables, one called 'employees' and another called 'addresses'. In the employees table you include a field called 'city' and you also include this field in the addresses table. The reason you might do something like this is that you want to be able to get a basic idea of where your employee lives without having to look up the address so you include it in both locations.

Why is this bad? well it should be obvious but here it is. Its bad because it allows for inaccuracies. What if the employee moves and changes his address and you forget to change the city listed in the employees table (or your system crashes while you trying to do it)

the proper way to do this would be to not have the 'city' field in the employee table and instead have a reference to the address table. When querying this info you need to join the two tables and this will ensure that you always have the correct info.

-Dallas Caley

Answer 2

Main purposes of normalisation in a relational database: * Eliminate redundancy * Organise data efficiently * Reduce the potential for data anomalies

Answer 3

To reduce the data redundancy and saving disk space.