RocketRML - A NodeJS implementation of a use-case specific RML mapper

Umutcan Şimşek, Elias Kärle, Dieter Fensel

Keywords: RML, RML Mapper, RDF generation, NodeJS

TL;DR: A RML Mapper implementation with NodeJs to support a specific real-life use case.

Abstract:

The creation of Linked Data from raw data sources is, in theory, no
rocket science (pun intended). Depending on the nature of the input and
the mapping technology in use, it can become a quite tedious task. For
our work on mapping real-life touristic data to the schema.org vocabulary
we used RML but soon encountered, that the existing Java mapper implementations reached their limits and were not sufficient for our use cases. In
this paper we describe a new implementation of an RML mapper. Written
with the JavaScript based NodeJS framework it performs quite well for
our uses cases where we work with large XML and JSON files. The performance testing and the execution of the RML test cases have shown, that
the implementation has great potential to perform heavy mapping tasks
in reasonable time, but comes with some limitations regarding JOINs,
Named Graphs and inputs other than XML and JSON - which is fine,
due to the nature of the given use cases.

Contribution: In Use and Experience papers (8-12 pages)