Consortium of companies Instytut Informatyki Gospodarczej (I2G) and Inwebit were responsible for one of the e-services – "Integrated search service OMNIS". This service allows searching the resources of all libraries in Poland from one place, also based on full-text of books, magazines and articles in a digital form. The outcomes of our work allow the sharing of the above data in the Linked Open Data model and data re-use by third parties through the open OMNIS API.

As a result of analytical work and software development performed within the Omnis Linked Data module in the Metadata Hub, ontology and metadata mappings were delivered. An innovative solution was proposed, which allows creating logical diagrams of OMNIS ontologies and the corresponding translation scripts from one metadata sheet, thus maintenance of the entire solution is simplified. The relational model is converted into Linked Data with automatically generated scripts in RML (RDF Mapping Language). The consortium developed extensions to the standard implementation of the RML engine that support the specifics of data of the National Library.

The essence of Linked Data is not just translating data from non-semantic models, but first and foremost linking with other resources. We developed scripts in Python that associated the OMNIS data model resources (in particular, the National Library Descriptors) with the following external datasets: VIAF (Virtual International Authority File), ISNI (International Standard Name Identifier), ORCID (Open Researcher and Contributor ID), Wikidata and GeoNames. To make linking of identifiers possible, we indexed external resources in Elasticsearch using proprietary data structures. Large volumes of processed data necessitated a range of optimization techniques to improve effectiveness of developed algorithms. As an extension to indexing we developed API for linking descriptors of any library on demand, The library can then contribute own resources to the integrated OMNIS search service.

The OMNIS e-service project [] was co-financed under the Operational Programme Digital Poland from the European Regional Development Fund and the state budget.

Project value: PLN 39 016 380,34

Contribution of European Funds: PLN 32 994 173,68

The project implementation timeline: October 2016 - September 2019