Often information is spread among
several data sources, such as hospital databases, lab databases,
spreadsheets, etc. Moreover, the complexity of each of these data sources
might make it difficult for end-users to access them, and even
more, to query all of them at the same time.
A new solution that has been proposed to this problem is
ontology-based data access (OBDA).
OBDA is a popular paradigm, developed since the mid 2000s, to query
various types of data sources
using a common vocabulary familiar to the end-users. In a nutshell
OBDA separates the user
from the data sources (relational databases, CVS files, etc.) by means
of an ontology, which is a common terminology that provides the user with a
convenient query vocabulary, hides the structure of the data sources,
and can enrich incomplete data with background knowledge. About a
dozen OBDA systems have been implemented in both academia and
In this tutorial we will give an overview of OBDA, and our system -ontop-
which is currently being used in the context of the European project
Optique. We will discuss how to use -ontop- for data integration,
in particular concentrating on:
– How to create an ontology (common vocabulary) for a life science domain.
– How to map available data sources to this ontology.
– How to query the database using the terms in the ontology.
– How to check consistency of the data sources w.r.t. the ontology