mDR is the name of the solution of a mapping problem I created for my master thesis at the faculty of mathematics and physics in 2007. Official assignment in Czech can be found at faculty pages. Said briefly in English, the task was to look for the existing solutions of mapping the relational database schema on already existing ontologies, primarily written in RDFS and the creation of a new system which would use a nice GUI interface. The words already existing are important, since there are lots of other solutions not taking this into account.
As a result of the work, the mDR solution was proposed. It generalises the existing FDR2 solution by Korotkiy M. and Top J. L. and uses a very special mapping ontology called mDR vocabulary(rdf/xml, png). A pilot implementation called JmDR written in Java language was even created. One input relation schema and two possible input ontologies about a fictional university were created:
Mapping is done in two steps. The creation of special (so called virtual and quasi elements) reflecting the database using a reverse engineering method and the matching of such elements with the elements of the existing input ontology. Example outputs of both phases of mapping the university schema to the ontology 2:
The JmDR application can handle various mapping situations, however there are naturally some which it does not like that much (see the first and second screenshot). After contacting me by mail, I could send you the application.
Title: Mapping of Relational Schema onto Existing Ontologies
Author: Peter Marko
Department: Department of Software Engineering
Supervisor: Mgr. Jaroslav Tykal
Abstract: This master thesis concerns the problematics of mapping of relational schemas to
existing ontologies, primarily written in RDFS. Its first part gives a view at already existing solutions and their
principles. The solutions are divided into the manual and semiautomatic groups according to
the level of a help given to users when mapping. Secondly the thesis presents an own solution - mDR. In its basics it does
use ideas of the existing FDR2 system, however it generalises them. The mapping is done in three steps:
creation of helping information about a database, mapping and instances transfer. The last third of the work
involves JmDR, a (in JAVA) developed tool completely implementing the first two phases.
The text is available in slovak only. Should anybody be interested, I could send him/her the full version in PDF format after contacting me by mail.
