Fuseki : Data Services

Fuseki provides a number of "data services" - each data service is an RDF datasets and a configurable set of endpoints for various operations such as SPARQL query, SPARQL update and file upload.

URI scheme. Datasets and services Admin

SPARQL Protocol

Queyr update GSP including direct naming for GSP

in addition:

Dataset as a set of quads.


@@ Just rough notes : out-of-date and inconsistent

Naming

The naming style for application operations is:

/ name / endpoint ? parameters

where name is

and endpoint is

In the administration operations, the name is used after the

/$/

e.g.

In administration operations, the dataset name is appended to the operation. For example, http://host:port/$/datasets/ds accesses the assembler description of the dataset.

There is also an internal name, generated by the server which is a UUID. This UUID is never reused even if the dataset name is reused after the first use is deleted.

Services and Datasets

Service

Query

GEThttp://host:port/dataset?query=..

POST http://host:port/dataset
Content-type: application/sparql-query

Update

POST http://host:port/dataset?update=...
POST http://host:port/dataset?update

or

POST http://host:port/dataset
Content-type: application/sparql-update

GSP

http://host:port/dataset?default
http://host:port/dataset?graph=...

The Dataset Lifecycle

The lifecycle of a dataset

  • Active
  • Offline

An active dataset is able to process applications requests.

An offline dataset is one whose configuration is know to the server but is currently not controlled by the server.

When offline, the dataset is unavailable for application requests but the name remains in-use and the configuration information retained. When made active again, the dataset and it's associated services are recreated. When offline, Fuseki does not retain any access to the data so the dataset can be changed with tools outside of Fuseki. When active, Fuseki assumes it has full control of a dataset (in particular TDB datasets can not be updated by other applications while active).

When Fuseki is not running, all datasets can be considered offline even if they were not explicitly made so prior to shutdown of the server.

(If a dataset uses in-memory storage, changes to its state are lost even though it is recreated from its; configuration when the server restarts.)