Data Models

Data model describes the organization of different database object namely, records, data dictionary, element, etc. Three types of traditional models used for database object. There are:

Relational model

r

In relational data model, data is organised in the from of rows and column as in a table the table are referred to as relation in as relation in a relational data model. Roes of the table are referred to as tuples and columns of the a table are referred to as attributes.

Hierarchical model

tree

 

Hierarchical model was developed by IBM in 1968. A hierarchical model is like a structure of a tree with a records forming the branches of the tree. In this model, records are linked in the form of a organization chart.

Network model

net

The network data mode is different from relational data model and data is represented by collection of records and relationships among data are represented by  links. In this model, the collection of records are connected to one another by means of links. In network model, structure a records type can have multiple owners.