Interacting with Statistical Linked Data via OLAP Operations

Abstract

Abstract. Online Analytical Processing (OLAP) promises an interface to analyse Linked Data containing statistics going beyond other interaction paradigms such as follow-your-nose browsers, faceted-search interfaces and query builders. As a new way to interact with statistical Linked Data we define comon OLAP operations on data cubes modelled in RDF and show how a nested set of OLAP operations lead to an OLAP query. Then, we show how to transform an OLAP query to a SPARQL query which generates all required facts from the data cube. Both metadata and OLAP queries are issued directly on a triple store; therefore, if the RDF is modified or updated, changes are propagated directly to OLAP clients.

Enriching integrated statistical open city data by combining equational knowledge and missing value imputation

“…2. Whereas earlier we have transformed data for integration into RDF using our own, proprietary ontology, the Open City Data Pipeline represents all collected, integrated and predicted indicator values using the standardised RDF Data Cube vocabulary (QB) [4] which has proven to be a suitable format for flexible publication and consumption of numerical data [3,11,12] and for generating a unified view, the global cube [9]. 3.…”

“…When using QB, we can rely on an existing toolchain: similarly as multidimensional datasets in OLAP systems, datasets represented in QB can be queried using common OLAP operations using SPARQL [3,9,15]:…”

“…Even several larger cities provide data in on their own open data portals, e.g., Amsterdam, Berlin, London, or Vienna. 3 Increasingly, such data can be downloaded free of charge and used under liberal licenses.…”

“…The collection and integration is based on modelling numerical data as multidimensional datasets (data cubes); we use Statistical Linked Data [3] as a standardised format to publish both the data and the metadata of cubes in wrappers. Statistical Linked Data means using Linked Data and the RDF Data Cube (QB) vocabulary [4].…”

ASPG: Generating OLAP Queries for SPARQL Benchmarking

“…Kämpgen et al [13] describe an approach to map OLAP queries into SPARQL queries with the RDF Data Cube (QB) vocabulary [6]. Since many Linked Data and SPARQL queries do not use QB, we examine the semantics of the above OLAP operations and propose a mapping between OLAP and SPARQL queries that are not limited to specific vocabularies.…”