An open-source object-graph-mapping framework for Neo4j and scala: renesca

Abstract

The usage and application of graph databases is increasing. Many research problems are based on understanding relation- ships between data entities. This is where graph databases are power- ful. Nevertheless, software developers model and think in object-oriented software. Combining both approaches leads to a paradigm mismatch. This mismatch can be addressed by using object graph mappers (OGM). OGM adapt graph databases for object-oriented code, to relieve the developer. Most graph database access frameworks only support table- based result outputs. This defeats one of the strongest purposes of using graph databases. In order to harness both the power of graph databases and object-oriented modeling (e.g. type-safety, inheritance, etc.) we pro- pose an open-source framework with two libraries: (1) renesca, which is a graph database driver providing graph-query-results and change- tracking. (2) renesca-magic, a macro-based ER-modeling domain specific language (DSL). Both were tested in a graph-based application and lead to dramatic improvements in code size (factor 10) and extensibility of the code, with no significant effect on performance.