Go4Expert (http://www.go4expert.com/)
-   Database (http://www.go4expert.com/articles/database/)
-   -   Database Normalization (http://www.go4expert.com/articles/database-normalization-t299/)

Minty 30Oct2007 20:14

Re: Database Normalization
what do u do with tables having many to many relaionship.
because in the erd we make another table of containing the primary keys of both the tables.

its confussinnnn me how we change those tables in inf

vikas1234 11Sep2008 13:19

Re: Database Normalization
nice short tutorial on normalization ... I just would like to add that that too much normalization make lots of table so you should always go for optimal normalization ...

pradeep 11Sep2008 14:17

Re: Database Normalization
Very right said Vikas!

satyedra pal 20Apr2010 15:26

Re: Database Normalization
Normalization is the process of organizing data into tables in such a way that the results of using the database are always unambiguous or
the process of organizing data to minimize redundancy. Normalization divides a database into two or more tables and links relationships between the tables
Normalization is done in two step that puts data into tabular form by removing redundent data and then removes duplicated data from the relational tables.
In normalization we do:
Avoiding repetitive entries.
Increased speed and flexibility of queries.
Reducing required space of storage for data by removing redundent data.

It has following normal form:
1NF(Normal form)

smithshn 6May2010 00:39

Re: Database Normalization
When data records are in large form then there is required normalization.
Normalization is a process of removing data which is repeated and filtering data to identify a value as uniquely in a table.
In RDBMS there is different method for normalization of the records which is shown as below:
(1) 1st Normal Form
(2) 2nd Normal Form
(3) 3rd Normal Form
(4) 4th Normal Form
(5) 5th Normal Form
(6) BCNF - Boyce Codd Normal Form- In this normal form you have follow the 32 rules of it.

seomanju 3Dec2010 16:40

Re: Database Normalization
Thanks for this detail.

seomanju 3Dec2010 16:42

Re: Database Normalization
Data models are the techniques to handle our databases.

sneha123 13Dec2010 16:30

Re: Database Normalization

Originally Posted by pradeep (Post 5076)
Functional Dependency

Definition: A functional dependency occurs when one attribute in a relation uniquely determines another attribute. This can be written A -> B which would be the same as stating "B is functionally dependent upon A."
Examples: In a table listing employee characteristics including Social Security Number (SSN) and name, it can be said that name is functionally dependent upon SSN (or SSN -> name) because an employee's name can be uniquely determined from their SSN. However, the reverse statement (name -> SSN) is not true because more than one employee can have the same name but different SSNs.

Transitive Dependency

Definition: A type of functional dependency in which the value in a non-key field is determined by the value in another non-key field and that field is not a candidate key

Hello Pradeep,,,,sneha here,,its excellent job,,,,,Thanks lot for share with us,,,,,,,,,

samantha1230 28Mar2012 17:23

Re: Database Normalization
Thanks for letting me know about Normalization, I just heard this but now come to know what exactly it is.

All times are GMT +5.5. The time now is 15:41.