Before you can load data into a graph and write queries on TigerGraph, you must first define a graph schema. A graph schema in TigerGraph is made up of different vertex types and edge types. Each vertex and edge type have their own attributes.
Database definition operations happen in two stages:
A graph schema is a "dictionary" that defines the types of entities, vertices and edges, in the graph and how those types of entities are related to one another.
Each vertex or edge type has a name and a set of attributes (properties) associated with it.
For example, a
Book vertex could have title, author, publication year, genre, and language attributes.
To learn about the GSQL commands used to define a schema, see GSQL language reference: Defining a Graph Schema.
After you define a graph schema, you can still modify it. This includes but is not limited to:
Adding and dropping vertex or edge types to the graph schema.
Adding and dropping attributes to vertex or edge types.
Adding and dropping tags.
Adding and dropping tuples.
Data already stored in the graph and which is not logically part of the change will be retained. For example, if you had 100 Book vertices and then added an attribute to the Book schema, you would still have 100 Books, with default values for the new attribute. If you dropped a Book attribute, you still would have all your books, but the one attribute would be gone.
To learn about the GSQL commands used in modifying a schema, see GSQL language reference: Modifying a Graph Schema.
You can clear the entire graph data store and erase all related definitions, including graph schema, loading jobs, queries as well as users and roles. The data deletion cannot be undone; use with extreme caution. The REST++, GPE, and GSE components will be turned off.
$ gsql --reset
Resetting the catalog.
Shutdown restpp gse gpe ...
Graph store /home/tigergraph/tigergraph/gstore/0/ has been cleared!
The catalog was reset and the graph store was cleared.