A process that breaks down data into record groups for efficient processing. It is a process in which data attributes within a data model are organized to increase the cohesion of entity types. In other words, the goal of data normalization is to reduce and even eliminate data redundancy, an important consideration for application developers because it is incredibly difficult to stores object in a relational database that maintains the same information in several places. There are three main normal forms, each with increasing level of normalization:
* First Normal Form: Each field in a table contains different information. A relation is in 1Nf if and only if all underlying domains contain scalar values only. * Second Normal Form: Each field in a table that is not a determiner of the contents of another field must itself be a function of the other fields in the table. A relation is said to be in 2NF if and only if it is in the 1NF and every non-key attribute is irreducibly dependent on the primary key. * Third Normal Form: A relation is said to be in 3NF if and only if it is in the 2NF and all non-key attributes are mutually independent.
A Database System in which any database file can be a component of more than one of the database tables.
The Study used some methods in order to complete a feasible and reliable system. Primary Key
The Field in a database table that is indexed and maintains the main sequence of the table. It is a key such that the value of the key attributes will uniquely identify any tuple in the relation. A relation must not have more than one primary key. Foreign Key
Is a field or group of field in a database record that point to a key field or group of fields forming a key of another database record in some table. Usually a foreign key in one table refers to the primary key of another table. This way references can be made to link information together and it is an essential part of...
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