Relational to RDF Mapping and Transparent Data
Access for SPARQL over SQL Databases
Facts about Semantika
• True transparent data access.
• Non-intrusive and utilizes fully over
• Query language aligned with SPARQL.
• High priority on performance.
What is Semantika?
• Semantika is a robust, high-performance
RDB-to-RDF connector and data access
add-on API for Java and SQL. Semantika
provides interface for building semantic
query machine over your existing
database. The solution is non-intrusive
and risk-free for your valuable data.
What is Semantika?
• Semantika framework is based on
Ontology-based Database Access (OBDA)
paradigm that combines the best of
semantic discipline and relational database
• It offers API support and high processing
• Mapping domain entities and relational
• Solution for the infamous object-relation
• Finally application can focus on domain
• Using one query to retrieve sets of data
without knowing what relational database
is the target.
• The query articulation is no longer tight
on a speciﬁc data schema; instead it is
bundled with terminology of your own
through SPARQL language.
Why use Semantika?
• Simple to implement,
• Isn’t intrusive, no migration is required.
• Instant added-value to your existing data
• Query mechanism closely resembles SQL
so learning curve is low,
• Useful for data publishing to public.
What makes up a
• Domain Ontology,
• RDB/RDF Mapping Speciﬁcation,
• Semantika Conﬁguration
• A formal speciﬁcation of the domain
• A formal speciﬁcation about the relationship
between data in database and entities in
<predicate-object-map rr:predicate="firstName" rr:column="FIRST_NAME"/>
<predicate-object-map rr:predicate="lastName" rr:column="LAST_NAME"/>
<predicate-object-map rr:predicate="hireDate" rr:column="HIRE_DATE"/>
• ApplicationFactory - Consumer of
Semantika conﬁguration ﬁle. System
initialization happens here. Creates
• ApplicationManager - One instance per
app. Provides query engine for query
• SparqlQueryEngine - Default query engine
that takes input SPARQL and returns
• RdfMaterializerEngine - RDB-to-RDF
export tool. Useful for open data
Semantika Use Scenario
Semantika Core Framework
(reproduced from Optique 1.0: Semantic Access to Big Data presentation)
Things to Take In
• Semantika is a robust, non-intrusive
platform for your semantic search need.
• Semantika offers you a new and intelligent
way for querying relational data through
• Semantika helps to extract your domain
information into standard documents that
is useful for knowledge sharing.