KroXmlsources
The objective of this project is to experiment with XML data sources and DL-Lite query answering. This project would be built on top of the query answering and query unfolding techniques implemented in the Quonto reasoner, i.e., the student will not implement everything from scratch, instead he will reuse existing infrastructure (classes, etc) and extend appropriately to allow for:
- Definition of mapping language for XML databases
- Extension of the unfolding techniques to cope with these mappings
- Extension of the evaluation techniques to handle querying over the XML databases.
You will first evaluate several candidate XML databases (e.g., eXistDB, ozone, basex, etc) and choose an appropriate database to support in this project. Based on the query language supported by the chosen DB, you will define an appropriate mapping language and query unfolding (transformation from conjunctive queries over the ontology into queries over the XML database). The proposal should be implemented in extensions to the current OBDA and Quonto software to allow for querying Ontologies with mappings to XML databases using the OBDA Plugin for Protege 4 and the Quonto plugin for Protege 4. You will analyze the current structure of these software packages and provide a proposal of extension points to the current API's.
You will also provide a sample scenario in which all the features of the project are demonstrated, i.e., mappings, unfolding, query answering over an XML database.
Development in this project consist of extensions to existing modules in Quonto and ObdaLib as to allow for the functionality provided in your own proposal. The API of the project should be properly modularized with components that handle each of the tasks involved in the system as independent operations (e.g., mapping definition, parsing, query unfolding into XML queries, query evaluation). Each of these modules or extensions should be properly documented using JavaDoc and inline comments.
The final package of the project should include
- An extended functional version of Quonto and the OBDALib that implements your extensions.
- First deliverable. Document describing the proposal for XML mappings as well as the proposed extension points for both, Quonto and the OBDALib. The functionality of each of the modules of the system as well as the concrete implementation choices for each of them.
- Second deliverable. An initial overview of the status of the implementation detailing open issues.
- Third and final deliverable. A final document including the updated architecture and system proposal to reflect the final stage of the development. A simple user manual for the application. The software package described above.
- Tractable reasoning and efficient query answering in description logics: The DL-Lite family. Diego Calvanese, Giuseppe De Giacomo, Domenico Lembo, Maurizio Lenzerini, and Riccardo Rosati. J. of Automated Reasoning, 39(3):385-429, 2007. pdf
- Ontologies and databases: The DL-Lite approach. Diego Calvanese, Giuseppe De Giacomo, Domenico Lembo, Maurizio Lenzerini, Antonella Poggi, Mariano Rodriguez-Muro, and Riccardo Rosati. In Sergio Tessaris and Enrico Franconi, editors, Semantic Technologies for Informations Systems - 5th Int. Reasoning Web Summer School (RW 2009), volume 5689 of Lecture Notes in Computer Science, pages 255-356. Springer, 2009.
- Linking data to ontologies Antonella Poggi, Domenico Lembo, Diego Calvanese, Giuseppe De Giacomo, Maurizio Lenzerini, and Riccardo Rosati. J. on Data Semantics, X:133-173, 2008. pdf