Schema

Introduction to graph schemas and the schema builder in PuppyGraph

PuppyGraph uses schemas to structure the concepts (vertices and edges) within a graph.

Graph Concepts

Vertices

Vertices (also known as nodes) are the fundamental units of which graphs are formed. Think of them as points in a space where each point can represent an object, a person, a place, or any abstract concept. Vertices can have properties. For example, if a vertex represents a person, its properties might include name: John Doe, age: 30, and occupation: Software Engineer.

Edges

Edges are the connections between vertices. They signify relationships or interactions between the vertices. In a simple graph, an edge might just be a line connecting two vertices.

Similar to vertices, edges can have properties. These properties can describe the nature or characteristics of the relationship. For example, if an edge represents a friendship between two people, it might have properties like since: 2010, indicating when the friendship began.

Modeling Data into Concepts

Modeling Vertices from Tables

• All the rows for a specific vertex type needs to come from a single table.

• Each vertex table needs to have an identifier column.

Modeling Edges from Tables

PuppyGraph uses a directional edge model, indicating a relationship from one vertex (the source) to another (the target).

• All the rows for a specific edge type needs to come from a single table.

• Each edge table needs to have an identifier column.

• Each edge table needs to have columns corresponding to the ids of its end vertices.

JSON Representation

PuppyGraph has a JSON representation for its schemas.

Vertex

Field	Type	Description
label	string	A user-provided name for reference in edges and queries
mappedTableSource	MappedTableSource	Specifies how vertex maps to catalog
attributes	[]Attribute	Specifies additional attribute for queries.

Edge

Field	Type	Description
label	string	A user-provided name for reference in queries
from	string	The from vertex label
to	string	The to vertex label
mappedTableSource	MappedTableSource	Specifies how edge maps to catalog
attributes	[]Attribute	Specifies additional attribute for queries

MappedTableSource

Field	Type	Description
catalog	string	Catalog name matches the specified catalog schema.
schema	string	Schema name matches the schema inside the catalog.
table	string	Table name matches the table inside the catalog.
metaFields (Vertex)	object {"id" :"string"}	The vertex id fields inside the data source table. The id field must be string and unique.
metaFields (Edge)	object { "id" :"string", "from":"string", "to" :"string" }	id - The edge id fields inside the data source table. The id field must be string and unique. from, to - The from, to fields inside the data source table. The from and to field must be the id of the specified vertex.

AttributeSchema

Field	Type
name	string	The field name. The name must match the field name inside the data source table.
type	string	The data type of the attribute.

Building a Schema

The JSON form of the schema is comprehensive but verbose. To build a schema, it is recommended to use the Graph Schema Builderprovided in PuppyGraph web UI.