Neo4j - Virtual Nodes & Relationships

Introduction

Virtual nodes and relationships in Neo4j, particularly with the APOC library, allow users to create temporary structures in the database that do not persist to disk. This is useful for modeling scenarios where relationships need to be explored without altering the underlying data.

Key Concepts

Implementation

Step-by-Step Process

1. Install the APOC library in your Neo4j instance.
2. Use the `apoc.create.node` function to create a virtual node.
3. Use the `apoc.create.relationship` function to create a virtual relationship.
4. Execute your query utilizing these virtual entities.

Code Examples

                // Creating a virtual node
                CALL apoc.create.node(['Person'], {name: 'John Doe'}) YIELD node
                RETURN node;

                // Creating a virtual relationship
                MATCH (a:Person {name: 'John Doe'})
                CALL apoc.create.relationship(a, 'KNOWS', {since: 2021}, node) YIELD rel
                RETURN rel;
                

Best Practices

• Always ensure that virtual nodes and relationships are used only when necessary to avoid performance degradation.
• Keep the scope of virtual nodes small to maintain query efficiency.
• Use descriptive labels and properties for clarity when creating virtual entities.

FAQ