“ Database Normalization” By: Eko Prasetianto (09622009) Information Engineering Universitas Muhammadiah Gresik 2010 Understanding Database Normalization Normalization is a process to alter a table that has a specific problem into two or more tables, which no longer has a problem (Abdul Kadir, 2002: 52). The problem is usually an inconsistency (not normal) when the removal (delete), conversion (update) and reading (retrieving) in a database. Form of normalization is a rule that is imposed on the tables in the database and must be met by the tables at these levels normalized. There are various forms of normalization, such is not the normal form, first normal form, second normal form and third normal forms. The rules in each form of normalization is as follows (Abdul Kadir, 2002: 54): a. The shape is not normal This form is a collection of data to be stored, there is no necessity to follow a certain format, can be incomplete or duplicated data and data collected is. b. First normal form A table is said in the first normal form (1NF) if every single column value for each row. This means that the column name is repeated sufficiently represented by a column name (no need for an index in a given column name). c. Second normal form A table is in second normal form (2NF) if the table is in first normal form, all primary key columns not depend entirely on the primary key. A column is called depends entirely on the primary key if the value in a column is always worth the same for a same primary key value. d. Third normal form A table is in third normal form (3NF) if the table is in second normal form, each column is not the primary key does not have a transitive dependency on the primary key.