At ArcGIS Enterprise 10.9.1, named users in the Enterprise portal must be licensed with the ArcGIS Knowledge user type extension to create, edit, and update Knowledge Graph Server services. At ArcGIS Enterprise 11.0, your account no longer requires the ArcGIS Knowledge user type extension, but you must be signed in to the Enterprise portal to create, edit, and update Knowledge Graph Server services.
The delete operation is available for a knowledge graph service data model's named types resource. With this operation, you can delete an entity type or relationship type from the data model. Identify the type you want to delete by specifying the type name. Use the data model query operation to learn about the item types that are defined in the schema.
You must have sufficient privileges to edit content and editing must be enabled for the knowledge graph service for this operation to be successful. You can enable editing for a knowledge graph service in the same way that you enable it for a hosted feature layer. The knowledge graph service's strict property must not be set to true, which indicates the data model cannot be modified.
Requests and responses
This operation can only be performed by sending an HTTP POST request and receiving a Protocolbuffer Binary Format (PBF)-formatted response. Details of the response parameters are provided in the appropriate .proto file.
The following is a sample POST request to delete an entity type named Warehouse:
POST /webadaptor/rest/services/Hosted/SupplyChain/KnowledgeGraphServer/dataModel/edit/namedTypes/Warehouse/delete HTTP/1.1 Host: machine.domain.com Content-Type: application/x-www-form-urlencoded Content-Length: 
Create a PBF-formatted response to get feedback from the operation based on the DeleteNamedTypesResponse.proto file.