The role of Registry component is to provide the adequate functionality for the retrieval of Things. This Registry is in fact a semantic Registry and is backed by the core COSMOS ontology.
While the backing of the COSMOS ontology provides a common “language” for the description of Things, users are not required to have a thorough understanding of the semantic technologies used in order to describe and retrieve them. This is due to the fact that the Registry exposes a front-end which hides the complexity of the publishing and retrieval mechanisms.
The Registry’s back-end is responsible for adequate storage, retrieval and maintenance of these descriptions. Triple stores provide the support for the persistence of the semantic descriptions made for Things and other related entities and components. Moreover, the Registry exposes an API which can be used without any knowledge of the underlying technologies. Nevertheless, the exposed REST API also allows external clients (such as other components, Applications, Things) to connect to the Registry and access its functionalities.
The stores are accessed using SPARQL queries but the complexity of these queries is hidden to the user of the Thing's Registry. The API provides access to CRUD operations from a higher level (Thing's description) and handles transparently the triple creation, removal, update and deletion.
More information can be found in Deliverable D5.1.2