Modeling, Manipulating and Evolving Hybrid Polystores with HyDRa

Data-intensive system evolution is a complex and error-prone process, as most evolution scenarios impact several interdependent artefacts such as the application code, the data structures or data instances. This process is becoming even more challenging with the emergence of heterogeneous database architectures, commonly called hybrid polystores, that rely on a combination of several, possibly overlapping relational and NoSQL databases. This paper presents HyDRa, a framework aiming to facilitate the design, the manipulation and evolution of polystores thanks to (1) a novel modeling language representing conceptually and physically the databases and (2) an automatically generated conceptual data access API (Application Programming Interface). HyDRa automatically enforces cross-database data integrity constraints, does not require developers to master multiple data models and query languages and protect application code from schema and data reconfiguration changes.