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  • Category: SQL Server

    Explain Normalization in Details

    plz tell me about normalization.
    what is the type of that?
    what is the deiffrence detween that?
  • #620556

    Normalization is the process of eliminating the DataRedendency

    simply making well structured database.without partial dependency
    and functional dependency.


  • #620558
    Hi Priyanka,

    Normalisation is a process which is used to organising database in a well structured manner and avoid redundancy of data, i.e., repeating data again and again with giving relationships between data.

    I guess 6 Normal Forms are available. But i know only 3.

    First Normal Form : Enforces unique data that means avoid repeating data or duplicate values.
    We can solve this problem using creating of primary key.

    Second Normal Form : All other attributes should depend on the primary key.

    Third Normal Form : Avoid repeating data that means if we having huge table with no of columns, here we can separate that table into some more simple tables and give relationships to them.

    Prabu Thangavelu
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  • #620564

    Normalization is Set rules for creating Database.It is Used To avoid repetitive entries, increase performance.

    First Normal Form
    Third Normal Form
    Second Normal Form



  • #620566
    There are 4 normal forms namely..

    First Normal Form:

    In this Normal Form all values should be atomic. Set Primary key for not allowing duplicate column.

    Second Normal Form:

    With this normal form Foreign key concept is used. It wont allows for Duplicate row.

    Third Normal Form:

    We can reduce the column for aggregate function such as total,age calculation grade calculation. We no need to specify separate column instead we can assign that column in select query or in code behind itself.

    Boyce Code Normal Form

  • #620570
    normalization is used to remove data redundancy.
    De-normalization is reverse process.

  • #620575
    Normalization is the process of organizing data.
    To establish relationships between tables
    To make the database more flexible by eliminating redundancy and inconsistent dependency.

    Consider this table:

    Student Faculty Faculty_No Stud1 Stud2 Stud3
    Ram Latha 101 1001 1021 1041
    Kamal Priya 102 1061 1071 1091

    First Normal Form:
    Eliminate repeating groups in individual tables.
    Create a separate table for each set of related data.
    Identify each set of related data with a primary key.

    Student Faculty Faculty_No Stud1
    Ram Latha 101 1001
    Ram Latha 101 1021
    Ram Latha 101 1041
    Kamal Priya 102 1061
    Kamal Priya 102 1071
    Kamal Priya 102 1091

    Second Normal Form:
    Create separate tables for sets of values that apply to multiple records.
    Relate these tables with a foreign key.

    Student Faculty Faculty_No
    Ram Latha 101
    Kamal Priya 102

    Student Stud1
    Ram 1001
    Ram 1021
    Ram 1041
    Kamal 1061
    Kamal 1071
    Kamal 1091

    Third Normal Form:
    Eliminate fields that do not depend on the key.

    Student Faculty
    Ram Latha
    Kamal Priya

    Faculty Faculty_No
    Latha 101
    Priya 102

  • #620585
    [Response removed by Admin. Read forum policies.]
    "If u wish to reach the highest,begin at the lowest."

  • #620647
    Normalization is a scientific method of breaking down complex table structures into simple table structure by using certain rules.

    Benefits of normalization of the database includes:

    1) Avoiding repetitive entries.
    2) Reducing required storage space.
    3) Preventing the need to restructure existing tables to accommodate new data.
    4) Increased speed and flexibility of queries, sorts and summaries.

    First Normal Form

    A relation is said to be in First Normal Form (1NF) if the values in the domain of each attribute of the relation are atomic. In other words, only one value is associated with each attribute and the value is not a set of values or a list of values.

    Second Normal Form

    A relation R is in second normal form (2NF) if it is in the 1NF and if all non-key attributes of R are fully functionally dependent on the primary key of R.

    Third Normal Form

    A relation R is in third normal form (3NF) if and only if it is in 2NF and no non-key attribute of R is transitively dependent on the primary key of R.

    Boyce-Codd Normal Form

    A relation R is in Boyce-Codd Normal Form (BCNF) if and only if every determinant is a candidate key.

    Thanks & Regards
    Paritosh Mohapatra
    Microsoft MVP (ASP.Net/IIS)
    DotNetSpider MVM

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