Understanding the Network Database Model

Database model invented by Charles Bachman.

The Network Database Model is a type of database model that allows multiple member records to be linked to multiple owner files and vice versa. This model is a flexible way of representing objects and their relationships.

Structure and Characteristics of the Network Model

The Network Model is based on a flexible approach to building database systems, which allows a child record to have multiple parent records. This model is designed as a network of records connected to each other through links, and each record can have multiple parent and child records.

The main components of the Network Model are:

• Records: These are similar to rows in a relational database model. Each record is a collection of fields (attributes), each of which contains only one data value.

• Sets: These are used to define one-to-many relationships between records. A set comprises two types of records: an owner record (parent) and a member record (child). A member record can have more than one owner.

Advantages of the Network Model

• Flexibility: The Network Model can handle more relationship types, such as many-to-many relationships, which are not possible in the hierarchical model.

• Data Integrity: Since the child can have more than one parent, there is no need to duplicate the child data, thus maintaining data integrity.

• Data Access: It allows easy navigation and access to data as it follows a navigational system.

Disadvantages of the Network Model

• Complexity: The Network Model is more complex to design and manage due to its many-to-many relationships.

• Lack of Structural Independence: Any changes in the database structure require changes in all the application programs that access the database.

• Data Redundancy: Although less than in the hierarchical model, some data redundancy still exists in the network model.

Real-world Examples of Network Model

The Network Model was widely used in the 1970s and 1980s, especially in applications that required high performance and navigational access, such as banking systems, airline reservation systems, and telecommunication systems. Today, it is less common but still used in certain systems where complex relationships exist.

In conclusion, the Network Database Model, with its ability to represent complex relationships and ensure data integrity, is a powerful tool for certain types of applications. However, its complexity and lack of structural independence make it less suitable for general-purpose applications.