Network Model in DBMS

April 8, 2021

Network model in DBMS

In 1970s CODASYL (conference on data system language) introduced a network model which is an extension to the hierarchical model but the difference is that the network model uses many to many rather than one to many.
In 1970 IBM introduced IDMS(information data management system), a product based on the network data model.

Data Organisation in the network model is just like a graph rather than a tree, a child record can have any number of parent records
This was the most widely used model before the relational database model was introduced

It was introduced to overcome the drawbacks of the hierarchical model because the hierarchical model uses one to many relationship as a result only a few relationships can be established.
Many to many relationships: But here in network model It uses many to many relationship where the child only is allowed to have more than one parent node as a result large number of relationships can be applied with different data tables and data access becomes easier and faster .

Consider two tables “employee” table and “date of joining” table with the help of this network model more than one employee record can be linked to 2 more than and one record in the “date of joining” table
For example, as shown in the figure both admin and HR uses the same data row present in the date of joining table i.e [2014] as a result data duplicate is reduced .

As more number of relationships or established between data tables it reduces data duplicity saves memory improve access time of data.