Graph Databases vs. Relational Databases: Pros, Cons, and Use Cases

You might be wondering about the differences between graph databases and relational databases. Both have their strengths and specific use cases. Understanding these can help you make informed decisions about which type of database suits your needs.

Let’s dive into what a graph database is and how it works.

What is a Graph Database?

A graph database is a type of NoSQL database. It is designed to store and query data with complex relationships. Instead of tables, it represents data as nodes and edges in a graph structure.

Nodes represent entities such as people, products, or any data item. Edges define the relationships between these nodes, like “friend,” “purchased,” or “connected to.” This structure allows for efficient querying and analysis of interconnected data. Learn more about what a graph database is and how they work.

You might be dealing with structured data and predefined schemas, making relational databases a familiar territory. But how do they compare?

What is a Relational Database?

A relational database organizes data into tables with predefined schemas. Each table consists of rows and columns, where rows represent individual records and columns represent attributes of those records. This structured format allows for efficient storage, retrieval, and management of data.

Relational databases use SQL (Structured Query Language) for querying and manipulating data. SQL provides a standardized way to interact with the database, enabling users to perform various operations such as inserting, updating, deleting, and selecting data. This makes it easier to manage and retrieve data in a consistent manner.

Relational databases enforce data consistency through ACID (Atomicity, Consistency, Isolation, Durability) properties. These properties ensure that all database transactions are processed reliably and maintain data integrity.

Examples of Relational Databases

  • MySQL: An open-source relational database management system widely used for web applications. It is known for its reliability, ease of use, and strong community support.

  • PostgreSQL: An advanced open-source relational database system that supports both SQL and JSON querying. It is known for its robustness, extensibility, and compliance with SQL standards.

  • Oracle Database: A commercial relational database system known for its high performance, scalability, and comprehensive feature set. It is widely used in enterprise environments for mission-critical applications.

Now, let’s explore why graph databases might be the right choice for your project with complex relationships and evolving data models.

Benefits of Graph Databases

Efficient Handling of Complex Relationships

Graph databases excel at managing highly connected data. When dealing with data that has numerous interconnections, such as social networks or organizational hierarchies, graph databases offer a clear advantage. They represent data as nodes and edges, making it straightforward to model and query complex relationships. For more insights, check out this case study on Dgraph performance.

Flexible Schema

Graph databases allow for evolving schemas, which is particularly useful when dealing with dynamic data models. Unlike relational databases that require predefined schemas, graph databases provide the flexibility to add new types of relationships or entities as your data model evolves. Learn more about streamline legacy data with Dgraph.

High Performance for Specific Use Cases

Graph databases deliver fast query performance for graph-based queries. They are optimized for operations that involve traversing relationships, making them highly efficient for specific use cases such as recommendation engines, fraud detection, and network analysis. Discover how FactSet uses Dgraph to power one of the largest financial databases in the world.

But what about the tried-and-true relational databases? Let’s see what they bring to the table.

Benefits of Relational Databases

Strong Consistency and ACID Compliance

Relational databases ensure data integrity through ACID properties, making them suitable for applications requiring strict consistency, such as financial systems, where accurate and reliable data processing is paramount.

Mature Ecosystem and Tooling

Relational databases have a mature ecosystem with extensive tooling and support. This mature ecosystem provides several advantages, including extensive tooling, wide adoption, and community support, and seamless integration with other technologies. Explore the rise of GraphQL databases and how they compare to traditional databases.

Understanding how each database type works can further clarify which one aligns with your project needs.

How Do Graph Databases Work?

Graph databases store data as nodes and edges. Nodes represent entities, such as people, products, or locations. Each node can have properties that describe the entity, like a person’s name or a product’s price. Edges define the relationships between these nodes.

Queries in graph databases traverse the graph to find patterns and connections. This traversal involves moving from one node to another through the edges. This method is efficient for exploring complex relationships and discovering insights that might be difficult to detect using traditional relational databases.

Graph databases use native graph storage and processing. This means they are optimized to handle graph structures directly, without the need for additional layers of abstraction. Learn more about graph data models.

Now, let’s consider some real-world scenarios where graph databases truly shine.

Graph Database Use Cases

Social Networks and Recommendation Engines

Graph databases excel at modeling and querying social connections. They represent users as nodes and relationships as edges, making it easy to traverse connections and uncover insights. Generating personalized recommendations based on user relationships becomes straightforward with graph databases.

Fraud Detection and Risk Assessment

Graph databases can identify complex fraud patterns and suspicious activities by analyzing relationships between entities. This capability allows for real-time fraud detection, reducing the risk of financial losses and enhancing security measures. Read more about Dgraph’s hybrid analysis and its advantages.

Knowledge Graphs and Ontologies

Graph databases are well-suited for representing and querying knowledge graphs. Knowledge graphs organize information into nodes and edges, capturing the relationships between different entities. Performing semantic reasoning becomes possible with graph databases. Find out more about the top graph database use cases.

Choosing between a graph database and a relational database depends on your data and how you plan to use it.

When to Use a Graph Database vs. a Relational Database

Use a Graph Database When Relationships Between Data Are Important

Graph databases shine when you need to manage and query complex relationships. If your data involves intricate connections, such as social networks, supply chains, or recommendation systems, a graph database is the way to go. Explore database sharding techniques for scaling graph databases.

Graph Databases Are Ideal for Highly Connected and Dynamic Data

When dealing with highly connected data, graph databases offer significant advantages. They handle dynamic data well, allowing you to add new nodes and relationships without disrupting the existing structure. Learn more about low-code development considerations and how Dgraph supports dynamic data.

Relational Databases Are Suitable for Structured Data with Predefined Schemas

Relational databases are the go-to choice for structured data with well-defined schemas. If your data fits neatly into tables and follows a consistent structure, a relational database will serve you well.

Consider Data Consistency Requirements

Data consistency is a key factor in choosing between these databases. Relational databases enforce strong consistency through ACID properties, making them suitable for applications that require reliable and consistent transactions.

Ecosystem Maturity

Relational databases benefit from a mature ecosystem with extensive tooling and support. This includes a wide range of ORMs, query builders, and visualization tools that can simplify development and data management.

When making your decision, consider your specific use cases and requirements.

Is a Graph Database Better Than a Relational Database?

The choice between a graph database and a relational database depends on your specific use cases and requirements. Each type of database has its strengths and is suited to different scenarios.

Graph databases excel at handling complex relationships and graph-based queries. Relational databases provide strong consistency and have a mature ecosystem. When deciding between the two, consider factors such as data structure, query patterns, and scalability needs.

Start building today with the world’s most advanced and performant graph database with native GraphQL. Explore our free tier to see how we can help you scale your applications effortlessly. Join us at Dgraph and leverage the power of graph technology for your next project.