1. An apparatus comprising: a processor configured to receive a first resource description format (RDF) triple for storage in an RDF store, the first RDF triple including a subject, predicate and object, the object comprising a uniform resource identifier-type (URI-type) or a literal-type object, wherein, for the first RDF triple including a literal-type object, the processor is configured to: identify a subtype of the object of the first RDF triple; semantically mark the object with the identified subtype, including being configured to generate a plurality of second RDF triples corresponding to the first RDF triple, the plurality of second RDF triples comprising an RDF triple including the subject and predicate of the first RDF triple as the subject and predicate thereof, and another RDF triple including the object of the first RDF triple or a representation of the object of the first RDF triple as the object thereof; and store the plurality of second RDF triples in the RDF store.