Data Model
An explanation of the Dataspace Connector’s data model.
The data model of the Dataspace Connector is based on the structure of the IDS Infomodel. On the top level, metadata of a data object is called a resource. This includes e.g. the title, a description, license information, and a list of contract offers. Resources are organized by catalogs. An IDS Connector can have multiple catalogs. A resource also has a list of representations that describes the offered data in more detail. This includes e.g. the data type. Below the representation, there is the artifact. This has a 1:1 relation to the raw data and describes e.g. checksum and bytesize. An artifact then has a reference to contract agreements, which describe the agreed usage between data provider and data consumer. Contract offers as contracts can contain multiple rules. Each rule may represent one IDS Usage Control Pattern as described here.
Furthermore, the Connector distinguishes between offered and requested resources. If data is offered, it is called an offered resource. The interfaces allow these resources to be modified and deleted without any restrictions. If data is requested by a consumer, it is stored as requested resource after being received. The interfaces for requested resources and contract agreements only allow interactions and manipulations that do not affect the technical assurance of data sovereignty. Also, requested resources cannot be registered as such with an IDS broker. Instead, an explicit offer must be created.
By default, the Dataspace Connector implements a subset of the IDS Infomodel. Some attributes can be defined via the interfaces, while others are gathered automatically. Each input is checked and empty inputs have a predefined default value. For a domain specific usage of the Dataspace Connector, each database entity has an additional “attributes” field, which allows storing custom key value pairs into the database.
An overview of all entities and its attributes are listed in the table below. Between all parent and child entities n to m relations are provided.
| Entity | Provided Attributes | Automated Attributes | Relations |
|---|---|---|---|
| catalog | title, description | created, modified | n offers, n requests |
| offer | title, description, keywords, publisher, sovereign, language, license, endpointDocumentation | version, created, modified | n representations, n contracts, n catalogs |
| request | title, description, keywords, publisher, sovereign, language, license, endpointDocumentation | version, created, modified | n representations, n contracts, n catalogs |
| representation | title, mediaType, language, standard | remoteId, created, modified | n artifacts, n offers/requests |
| artifact | title, accessUrl, username, password | remoteId, remoteAddress, numAccessed, automatedDownload, byteSize, checkSum, created, modified | n representations, n agreements |
| contract | consumer, provider, title, start, end | remoteId, created, modified | n rules, n offers/requests |
| rule | title, value | remoteId, created, modified | n contracts |
| agreement | - | remoteId, confirmed, archived, value, created, modified | n artifacts |
Mapping between the Dataspace Connector’s data model and the IDS Infomodel takes place for any IDS communication. Then a catalog with offered resources is built from all related objects.
Note: An offered resource is only complete if it contains at least one contract offer and at least one representation with at least one artifact. Otherwise, it will not be listed in the IDS self-description because there is no complete data offer.
An example IDS catalog could look like that:
{
"@context":{
"ids":"https://w3id.org/idsa/core/",
"idsc":"https://w3id.org/idsa/code/"
},
"@type":"ids:ResourceCatalog",
"@id":"https://localhost:8080/api/catalogs/9ca7ed44-4321-4bd7-8445-b771b5dc3904",
"ids:offeredResource":[
{
"@type":"ids:Resource",
"@id":"https://localhost:8080/api/offers/726b8938-9058-4cff-8aaf-47c1146ce98c",
"ids:language":[
{
"@id":"idsc:EN"
}
],
"ids:created":{
"@value":"2021-05-17T15:18:52.363Z",
"@type":"http://www.w3.org/2001/XMLSchema#dateTimeStamp"
},
"ids:version":"1",
"ids:description":[
{
"@value":"",
"@language":""
}
],
"ids:title":[
{
"@value":"",
"@language":""
}
],
"ids:sovereign":{
"@id":""
},
"ids:publisher":{
"@id":""
},
"ids:representation":[
{
"@type":"ids:Representation",
"@id":"https://localhost:8080/api/representations/9f1fc799-3bbf-4613-9e91-4d9d2f92fa97",
"ids:instance":[
{
"@type":"ids:Artifact",
"@id":"https://localhost:8080/api/artifacts/688c3e91-461c-4f1f-98e2-e2f7971e8cba",
"ids:fileName":"",
"ids:creationDate":{
"@value":"2021-05-17T15:18:52.749Z",
"@type":"http://www.w3.org/2001/XMLSchema#dateTimeStamp"
},
"ids:byteSize":32,
"ids:checkSum":"3110206735"
}
],
"ids:language":{
"@id":"idsc:EN"
},
"ids:created":{
"@value":"2021-05-17T15:18:52.566Z",
"@type":"http://www.w3.org/2001/XMLSchema#dateTimeStamp"
},
"ids:mediaType":{
"@type":"ids:IANAMediaType",
"@id":"https://w3id.org/idsa/autogen/iANAMediaType/7a5c145d-c6e8-48ff-a628-ac99f38f56ec",
"ids:filenameExtension":""
},
"ids:modified":{
"@value":"2021-05-17T15:18:52.566Z",
"@type":"http://www.w3.org/2001/XMLSchema#dateTimeStamp"
},
"ids:representationStandard":{
"@id":""
}
}
],
"ids:resourceEndpoint":[
{
"@type":"ids:ConnectorEndpoint",
"@id":"https://w3id.org/idsa/autogen/connectorEndpoint/84112ee0-01de-4284-879f-759ab94ade94",
"ids:endpointDocumentation":[
{
"@id":""
}
],
"ids:accessURL":{
"@id":"https://localhost:8080/api/offers/726b8938-9058-4cff-8aaf-47c1146ce98c"
}
}
],
"ids:contractOffer":[
{
"@type":"ids:ContractOffer",
"@id":"https://localhost:8080/api/contracts/747e6404-178b-4910-b35e-749b0a8057de",
"ids:permission":[
{
"@type":"ids:Permission",
"@id":"https://localhost:8080/api/rules/0c9e86dc-3453-461c-bdfc-e1fbb3e8ffe5",
"ids:description":[
{
"@value":"provide-access",
"@type":"http://www.w3.org/2001/XMLSchema#string"
}
],
"ids:title":[
{
"@value":"Example Usage Policy",
"@type":"http://www.w3.org/2001/XMLSchema#string"
}
],
"ids:action":[
{
"@id":"idsc:USE"
}
]
}
],
"ids:provider":{
"@id":""
},
"ids:consumer":{
"@id":""
},
"ids:contractEnd":{
"@value":"2021-05-17T15:18:52.906Z",
"@type":"http://www.w3.org/2001/XMLSchema#dateTimeStamp"
},
"ids:obligation":[
],
"ids:prohibition":[
],
"ids:contractDate":{
"@value":"2021-05-17T17:19:53.749+02:00",
"@type":"http://www.w3.org/2001/XMLSchema#dateTimeStamp"
},
"ids:contractStart":{
"@value":"2021-05-17T15:18:52.906Z",
"@type":"http://www.w3.org/2001/XMLSchema#dateTimeStamp"
}
}
],
"ids:keyword":[
{
"@value":"DSC",
"@language":""
}
],
"ids:standardLicense":{
"@id":""
},
"ids:modified":{
"@value":"2021-05-17T15:18:52.363Z",
"@type":"http://www.w3.org/2001/XMLSchema#dateTimeStamp"
}
}
]
}