Data Vault Ensemble Modeling

Graph Databases – Time Representation and Historical Analysis

Tue Kofoed-Enevoldsen, The Danish Environmental Protection Agency

The presentation concerns itself with the theoretical and practical challenge of representing time (i.e. change) and performing historical analysis using graph database technology. Graph database technology has risen to become one of NoSQL’s most prominent members, offering both intuitive data modeling concepts as well as advantageous query capabilities. However the issue of representing and querying dynamic rather than static graphs is still an underexplored topic with no established industry standards and only very few apparent best practices. From the perspective of data warehousing, this is clearly something that must be resolved, sooner rather than later. Based on work experience from within the Danish energy industry and Denmark´s tax authorities, the presentation brings forth multiple different options for modeling historical data sets as graph objects. In addition, hereto a method for logically categorizing a graph object´s temporal aspects is proposed.

Tue works as a data and information architect for the Danish Environmental Protection Agency. He and his architect colleagues are responsible for the design and implementation of the agency´s new data warehouse in which NoSQL technology will play an important role. Tue has a BA in Philosophy (specializing in systems theory) and a MD in Software Development Technology (specializing in Database Technology and Data Modeling). He wrote his master thesis in collaboration with the Danish company DONG ENERGY (now Ørsted), investigating the applicability of graph databases (specifically Neo4j) to storing and analyzing historical data stemming from DONG´s electricity grid (i.e. data concerning grid topology, volts and currents etc.). Furthermore, when working as a data architect for the Danish Tax Authorities from 2015 to 2018, Tue lead the data warehouse department´s exploration into the fitness of graph database technology for becoming a permanent component of the DW data architecture.