ontopProQuestPreferences

Table of Contents Using Ontop in Protégé Starting/Synchronizing/Stopping Ontop Quest Configuration First Order Reformulation Data Configuration

Using Ontop in Protégé

-ontopPro- works in the same way as any OWL reasoners work, however, it provides extra functionalities that makes it an attractive alternative for a wide range of scenarios.

Starting/Synchronizing/Stopping Ontop

In order to enable Quest in Protégé, you need to start it first by doing as follows:

1. Select the "Reasoner" in the menu bar,
2. Select "Ontop x.xx.x " as reasoner,
3. And immediately click "Start reasoner"

Once Quest is started you will be able to send SPARQL queries and retrieve the answers. This facility can be found under "Ontop SPARQL" tab.

Note that changes in the mappings or ontology are not detected automatically by Ontop. If you change any of these, you need to rerun the reasoner by doing synchronization as follows:

1. Select the "Reasoner" in menu bar,
2. Click on "Synchronize reasoner".

In some cases you may need to stop Ontop to restart it. To stop Ontop do as follows:

1. Select the "Reasoner" in menu bar,
2. Click on "None"
3. Restart Ontop by selecting again "Ontop x.xx.x" and "Start reasoner".

Quest Configuration

There is a couple of features that is available in Ontop but not to the other OWL reasoners. Users can configure some of the features using the preference window: "File" > "Preferences...". In the preference window select "Quest" tab.

NOTE: Any changes in the configuration require you to restart Quest.

First Order Reformulation

Users may :

• enable/disable the reasoning step to gain better performance in special case, e.g., when querying RDF data.
• enable/disable querying annotation property present in the ontology.
• enable/disable reasoning with owl:sameAs from mappings .

Data Configuration

• Virtual RDF Graph mode. In this mode, Quest will not import any data from the data source. All reasoning will be done on-the-fly by means of query-rewriting. Quest computes the answers from your query over the ontology and generates one single SQL query to be executed through a database system. Currently, Quest allows a single data source only.
• Classic RDF Graph mode. In this mode, Quest will read individual assertions from the OWL file as well as "extract" individual assertions from the mappings of your OBDA model.

For a full description of Virtual and Classic ABox mode, please refer to this document.