Differences Between Hierarchical and Network and Relational Models: 7 Key Insights

The Differences Between Hierarchical and Network and Relational Models lie in how data is structured, linked, and queried within database systems. Each model has strengths and weaknesses, making it crucial to select the right one for your application.

What Are Data Models in DBMS?

Data models define the rules for organizing, storing, and managing data in a Database Management System (DBMS). They create a framework that shapes how developers design databases and how users retrieve information.

Among the oldest and most influential are the Hierarchical, Network, and Relational Models, which remain relevant in both legacy systems and modern database designs. Understanding their differences helps businesses and developers choose the right model for performance, flexibility, and scalability.

Hierarchical Data Model Overview

The Hierarchical Data Model arranges data in a tree-like structure. A parent node may have multiple children, but each child belongs to only one parent. This strict hierarchy makes it ideal for one-to-many relationships.

• Example: File systems where folders contain subfolders and files.
• Use Case: Best suited for applications with predictable, structured hierarchies.

Features of Hierarchical Model

• Data is accessed from top to bottom using parent-child relationships.
• Navigation is straightforward for predefined paths.
• Data retrieval is efficient for hierarchical queries.

Advantages

• Fast data retrieval for structured, repetitive access patterns.
• Simplifies management of one-to-many relationships.

Disadvantages

• Limited flexibility for many-to-many relationships.
• Difficult to modify or expand when requirements evolve.

Network Data Model Overview

The Network Data Model represents data using a graph structure with nodes (entities) and edges (relationships). Unlike the hierarchical model, entities can be connected to multiple parents and children, supporting many-to-many relationships.

• Example: Airline route maps where multiple cities connect via different flights.
• Use Case: Useful for telecommunications, transport systems, and supply chains.

Features of Network Model

• Uses pointers to define complex relationships.
• Supports multiple data paths for navigation.
• Handles real-world scenarios with interconnected entities.

Advantages

• Efficient for modeling complex relationships.
• More flexible than hierarchical systems.
• Allows multiple ways to access related data.

Disadvantages

• Complex to implement and maintain.
• Navigation can be challenging for beginners.

Relational Data Model Overview

The Relational Data Model organizes data in tables (relations) with rows (records) and columns (attributes). Relationships are created using primary keys and foreign keys. SQL (Structured Query Language) makes it easy to query and manipulate data.

• Example: Customer orders in e-commerce, where tables store customers, products, and transactions.
• Use Case: General-purpose databases across industries such as banking, healthcare, and retail.

Features of Relational Model

• Data stored in tabular form with clear structure.
• Relationships defined via keys.
• SQL provides powerful querying and manipulation.

Advantages

• Highly flexible and widely adopted.
• Easier for beginners to learn compared to hierarchical or network models.
• Supports complex queries and ad-hoc analysis.

Disadvantages

• Performance may degrade with massive datasets.
• Not ideal for highly hierarchical or graph-like data.

Key Differences Between Hierarchical, Network, and Relational Models

1. Structure

• Hierarchical Model: Tree structure with strict parent-child relationships.
• Network Model: Graph structure supporting multiple connections.
• Relational Model: Tabular format with rows and columns.

2. Relationships

• Hierarchical: One-to-many only.
• Network: Many-to-many supported.
• Relational: Supports one-to-one, one-to-many, and many-to-many.

3. Query Language

• Hierarchical & Network: Rely on procedural data manipulation languages (DL/PL).
• Relational: Uses SQL, a declarative language, making queries simpler.

4. Flexibility

• Hierarchical: Rigid, not suitable for evolving data needs.
• Network: Moderate flexibility but complex.
• Relational: Highly flexible and scalable.

5. Ease of Implementation

• Hierarchical: Moderate, but expansion is difficult.
• Network: Complex, requires advanced understanding.
• Relational: Simplest to implement with wide tool support.

Applications of Each Model

• Hierarchical Model: Still used in file systems, XML databases, and directory services like LDAP.
• Network Model: Found in telecom billing systems, transport logistics, and reservation systems.
• Relational Model: Dominates modern applications including ERP, CRM, banking, e-commerce, and analytics platforms.

Why Relational Models Dominate Modern Databases

Relational models became popular due to their simplicity, scalability, and SQL support. Businesses need flexible systems that adapt to dynamic data, and relational models provide this. While hierarchical and network models still exist in legacy systems, relational databases remain the standard.

However, with the rise of NoSQL and graph databases, network-style data modeling is regaining importance for highly connected data such as social networks and recommendation engines.

Comparison Table: Hierarchical vs. Network vs. Relational

Aspect	Hierarchical Model	Network Model	Relational Model
Structure	Tree	Graph	Table
Relationships	One-to-Many	Many-to-Many	All Types
Ease of Use	Moderate	Complex	Simple
Flexibility	Low	Moderate	High
Query Language	Procedural	Procedural	SQL
Use Cases	File systems, XML	Telecom, Transport	Banking, E-commerce

Conclusion

The Differences Between Hierarchical and Network and Relational Models highlight the evolution of database design. Hierarchical models suit rigid structures, network models handle complex relationships, and relational models balance usability with flexibility. Choosing the right model depends on the application’s complexity, scalability needs, and data access patterns.

FAQs: Differences Between Hierarchical, Network, and Relational Models