What is difference between the Network model and Hierarchical model?

In Hierarchical data model, relationship between table and data is defined in parent child structure. In this structure data are arranged in the form of a tree structure. This model supports one-to-one and one-to-many relationships.

On the other hand, network model arrange data in graph structure. In this model each parents can have multiple children and children can also have multiple parents. This model supports many to many relationships also.

The Network model and Hierarchical model are both data models used in database management systems, but they have some key differences:

• Structure: The Hierarchical model is based on a tree-like structure, where each record has a single parent and zero or more children. In contrast, the Network model is based on a graph-like structure, where each record can have multiple parent and child records.

• Flexibility: The Network model is more flexible than the Hierarchical model because it allows for more complex relationships between records. In the Network model, records can have many-to-many relationships, whereas in the Hierarchical model, records can only have one-to-many relationships.

• Navigation: The Hierarchical model is easier to navigate than the Network model because it follows a strict parent-child relationship. To access a child record in the Hierarchical model, you simply follow the path from the parent record to the child record. In the Network model, however, you may have to traverse multiple paths to access a child record that has multiple parent records.

• Performance: The Hierarchical model is generally faster than the Network model because it has a simpler structure and requires fewer joins to access data. However, the performance difference may not be significant in smaller databases.

• Complexity: The Network model is more complex than the Hierarchical model because it requires more knowledge of graph theory and may require more complex queries to access data. The Hierarchical model is simpler and easier to understand.